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FA-92786 / HVAC thermostat control / Open access

Compressor starts on the same sample the reversing valve shifts · case 01

The valve shifts under full differential pressure, producing a loud whoosh and valve wear.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The compressor output ignores whether the valve changed position.

VERIFIED REPAIR

Hold the compressor off on the sample the valve shifts.

Unsuccessful approach: Waiting only for shifts into heating still starts against a shifting valve for cooling.

Case contract

Heat pump reversing valve output (O/B terminal) and compressor per sample; samples are the call (heat, cool or None). An O-type valve is energized for cooling, a B-type for heating. The valve is de-energized at power-up and holds its last position while idle. On a sample where the valve changes position the compressor waits (off) for pressure equalization. Return [compressor, valve_energized].

Why this case matters

Residential and light-commercial thermostats make these decisions sample by sample; each defect changes equipment calls in a way that shows up as short cycling, comfort complaints or equipment stress.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(valve_type, samples):
    valve = False
    out = []
    for call in samples:
        if call is None:
            out.append([False, valve])
            continue
        want = (call == 'cool') if valve_type == 'O' else (call == 'heat')
        changed = want != valve
        valve = want
        out.append([True, valve])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 1',
   ['B', ['cool', 'heat', 'heat', None, None, 'cool', 'cool', 'heat', 'heat', 'heat', 'heat']],
   [[True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [False, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['regression: scenario 2',
   ['B',
    ['heat',
     'heat',
     'cool',
     'cool',
     'heat',
     None,
     'heat',
     'cool',
     'heat',
     'heat',
     'cool',
     None,
     'heat',
     'cool']],
   [[False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, True],
    [False, True],
    [True, True],
    [False, False],
    [False, True],
    [True, True],
    [False, False],
    [False, False],
    [False, True],
    [False, False]]],
  ['regression: scenario 3',
   ['O', ['cool', 'cool', 'cool', 'heat', None, None, 'heat', 'cool', 'heat', 'heat', None, 'heat', 'heat']],
   [[False, True],
    [True, True],
    [True, True],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [True, False]]],
  ['regression: scenario 4',
   ['B', [None, 'heat', 'cool', 'cool', 'cool', 'cool', 'heat', 'heat', None, 'cool']],
   [[False, False],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, False]]]],
 [['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: scenario 1',
   ['B', [None, None, 'heat', None, 'cool', 'cool', 'cool', 'heat', None, 'cool', None]],
   [[False, False],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 2',
   ['B', ['heat', 'cool', 'heat', None, 'cool', 'heat', None, 'heat', None, 'cool', None]],
   [[False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 3',
   ['B', [None, 'heat', None, None, None, None, 'cool', 'heat', 'heat', None]],
   [[False, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [True, True],
    [False, True]]],
  ['regression: scenario 4',
   ['B', ['heat', 'cool', 'cool', 'heat', 'heat', None, 'heat']],
   [[False, True], [False, False], [True, False], [False, True], [True, True], [False, True], [True, True]]]],
 [['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: scenario 1',
   ['B', ['cool', 'heat', 'heat', 'cool', 'cool', None, 'cool', 'heat', 'heat', None, None, 'heat']],
   [[True, False],
    [False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [True, True]]],
  ['regression: scenario 2',
   ['O', [None, 'cool', 'heat', 'cool', 'heat', 'heat']],
   [[False, False], [False, True], [False, False], [False, True], [False, False], [True, False]]],
  ['regression: scenario 3',
   ['B', ['cool', 'heat', None, None, None, 'heat', 'heat', 'cool']],
   [[True, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, False]]],
  ['regression: scenario 4',
   ['O', ['heat', 'heat', 'heat', 'heat', 'heat', 'cool', None, 'cool', 'cool', None]],
   [[True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True]]]],
 [['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 3',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'heat', 'cool', 'heat', None, 'heat', None, 'heat']],
   [[False, True],
    [True, True],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [True, False]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: scenario 1',
   ['O', ['heat', 'cool', None, 'cool', None, None, 'cool']],
   [[True, False], [False, True], [False, True], [True, True], [False, True], [False, True], [True, True]]],
  ['regression: scenario 2',
   ['B', ['cool', 'cool', 'heat', None, 'cool', 'cool', None, 'cool']],
   [[True, False],
    [True, False],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False]]],
  ['regression: scenario 4',
   ['O', ['cool', None, None, 'heat', 'cool', None, 'heat', None, None, 'cool', 'cool']],
   [[False, True],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, False],
    [False, False],
    [False, True],
    [True, True]]]],
 [['regression: scenario 1',
   ['O', ['heat', None, 'cool', None, 'heat', 'cool', 'heat', 'cool', None, None, None]],
   [[True, False],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True]]],
  ['regression: scenario 3',
   ['O', ['heat', 'cool', 'cool', 'heat', 'heat', None, 'heat', None, 'heat', 'heat', 'cool', 'cool']],
   [[True, False],
    [False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [True, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 2',
   ['B', [None, None, None, None, 'cool', None, 'heat', 'cool', None]],
   [[False, False],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 4',
   ['B', [None, 'heat', 'heat', None, 'cool', None, 'cool', None]],
   [[False, False],
    [False, True],
    [True, True],
    [False, True],
    [False, False],
    [False, False],
    [True, False],
    [False, False]]]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: O valve season change[[True, True], [True, True], [False, True], [True, False], [True, False], [True, True]][[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]Failed
regression: B valve idle hold[[True, True], [False, True], [True, True]][[False, True], [False, True], [True, True]]Failed
regression: first call heat on O[[True, False], [True, False], [False, False], [True, True]][[True, False], [True, False], [False, False], [False, True]]Failed
regression: first call cool on B[[True, False], [False, False], [True, False], [True, True]][[True, False], [False, False], [True, False], [False, True]]Failed
regression: scenario 1[[True, False], [True, True], [True, True], [False, True], [False, True], [True, False], [True, False], [True, True], [True, True], [True, True], [True, True]][[True, False], [False, True], [True, True], [False, True], [False, True], [False, False], [True, False], [False, True], [True, True], [True, True], [True, True]]Failed
regression: scenario 2[[True, True], [True, True], [True, False], [True, False], [True, True], [False, True], [True, True], [True, False], [True, True], [True, True], [True, False], [False, False], [True, True], [True, False]][[False, True], [True, True], [False, False], [True, False], [False, True], [False, True], [True, True], [False, False], [False, True], [True, True], [False, False], [False, False], [False, True], [False, False]]Failed
regression: scenario 3[[True, True], [True, True], [True, True], [True, False], [False, False], [False, False], [True, False], [True, True], [True, False], [True, False], [False, False], [True, False], [True, False]][[False, True], [True, True], [True, True], [False, False], [False, False], [False, False], [True, False], [False, True], [False, False], [True, False], [False, False], [True, False], [True, False]]Failed
regression: scenario 4[[False, False], [True, True], [True, False], [True, False], [True, False], [True, False], [True, True], [True, True], [False, True], [True, False]][[False, False], [False, True], [False, False], [True, False], [True, False], [True, False], [False, True], [True, True], [False, True], [False, False]]Failed

SHA-256 / 81c1d2014d9751d6ca282c24ec7bafe12d78af9bf2d57f8be166e07c70288641

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(valve_type, samples):
    valve = False
    out = []
    for call in samples:
        if call is None:
            out.append([False, valve])
            continue
        want = (call == 'cool') if valve_type == 'O' else (call == 'heat')
        changed = want != valve
        valve = want
        out.append([not changed or call == 'heat', valve])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 1',
   ['B', ['cool', 'heat', 'heat', None, None, 'cool', 'cool', 'heat', 'heat', 'heat', 'heat']],
   [[True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [False, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['regression: scenario 2',
   ['B',
    ['heat',
     'heat',
     'cool',
     'cool',
     'heat',
     None,
     'heat',
     'cool',
     'heat',
     'heat',
     'cool',
     None,
     'heat',
     'cool']],
   [[False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, True],
    [False, True],
    [True, True],
    [False, False],
    [False, True],
    [True, True],
    [False, False],
    [False, False],
    [False, True],
    [False, False]]],
  ['regression: scenario 3',
   ['O', ['cool', 'cool', 'cool', 'heat', None, None, 'heat', 'cool', 'heat', 'heat', None, 'heat', 'heat']],
   [[False, True],
    [True, True],
    [True, True],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [True, False]]],
  ['regression: scenario 4',
   ['B', [None, 'heat', 'cool', 'cool', 'cool', 'cool', 'heat', 'heat', None, 'cool']],
   [[False, False],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, False]]]],
 [['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: scenario 1',
   ['B', [None, None, 'heat', None, 'cool', 'cool', 'cool', 'heat', None, 'cool', None]],
   [[False, False],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 2',
   ['B', ['heat', 'cool', 'heat', None, 'cool', 'heat', None, 'heat', None, 'cool', None]],
   [[False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 3',
   ['B', [None, 'heat', None, None, None, None, 'cool', 'heat', 'heat', None]],
   [[False, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [True, True],
    [False, True]]],
  ['regression: scenario 4',
   ['B', ['heat', 'cool', 'cool', 'heat', 'heat', None, 'heat']],
   [[False, True], [False, False], [True, False], [False, True], [True, True], [False, True], [True, True]]]],
 [['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: scenario 1',
   ['B', ['cool', 'heat', 'heat', 'cool', 'cool', None, 'cool', 'heat', 'heat', None, None, 'heat']],
   [[True, False],
    [False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [True, True]]],
  ['regression: scenario 2',
   ['O', [None, 'cool', 'heat', 'cool', 'heat', 'heat']],
   [[False, False], [False, True], [False, False], [False, True], [False, False], [True, False]]],
  ['regression: scenario 3',
   ['B', ['cool', 'heat', None, None, None, 'heat', 'heat', 'cool']],
   [[True, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, False]]],
  ['regression: scenario 4',
   ['O', ['heat', 'heat', 'heat', 'heat', 'heat', 'cool', None, 'cool', 'cool', None]],
   [[True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True]]]],
 [['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 3',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'heat', 'cool', 'heat', None, 'heat', None, 'heat']],
   [[False, True],
    [True, True],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [True, False]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: scenario 1',
   ['O', ['heat', 'cool', None, 'cool', None, None, 'cool']],
   [[True, False], [False, True], [False, True], [True, True], [False, True], [False, True], [True, True]]],
  ['regression: scenario 2',
   ['B', ['cool', 'cool', 'heat', None, 'cool', 'cool', None, 'cool']],
   [[True, False],
    [True, False],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False]]],
  ['regression: scenario 4',
   ['O', ['cool', None, None, 'heat', 'cool', None, 'heat', None, None, 'cool', 'cool']],
   [[False, True],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, False],
    [False, False],
    [False, True],
    [True, True]]]],
 [['regression: scenario 1',
   ['O', ['heat', None, 'cool', None, 'heat', 'cool', 'heat', 'cool', None, None, None]],
   [[True, False],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True]]],
  ['regression: scenario 3',
   ['O', ['heat', 'cool', 'cool', 'heat', 'heat', None, 'heat', None, 'heat', 'heat', 'cool', 'cool']],
   [[True, False],
    [False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [True, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 2',
   ['B', [None, None, None, None, 'cool', None, 'heat', 'cool', None]],
   [[False, False],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 4',
   ['B', [None, 'heat', 'heat', None, 'cool', None, 'cool', None]],
   [[False, False],
    [False, True],
    [True, True],
    [False, True],
    [False, False],
    [False, False],
    [True, False],
    [False, False]]]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: O valve season change[[False, True], [True, True], [False, True], [True, False], [True, False], [False, True]][[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]Failed
regression: B valve idle hold[[True, True], [False, True], [True, True]][[False, True], [False, True], [True, True]]Failed
regression: first call heat on O[[True, False], [True, False], [False, False], [False, True]][[True, False], [True, False], [False, False], [False, True]]Passed
regression: first call cool on B[[True, False], [False, False], [True, False], [True, True]][[True, False], [False, False], [True, False], [False, True]]Failed
regression: scenario 1[[True, False], [True, True], [True, True], [False, True], [False, True], [False, False], [True, False], [True, True], [True, True], [True, True], [True, True]][[True, False], [False, True], [True, True], [False, True], [False, True], [False, False], [True, False], [False, True], [True, True], [True, True], [True, True]]Failed
regression: scenario 2[[True, True], [True, True], [False, False], [True, False], [True, True], [False, True], [True, True], [False, False], [True, True], [True, True], [False, False], [False, False], [True, True], [False, False]][[False, True], [True, True], [False, False], [True, False], [False, True], [False, True], [True, True], [False, False], [False, True], [True, True], [False, False], [False, False], [False, True], [False, False]]Failed
regression: scenario 3[[False, True], [True, True], [True, True], [True, False], [False, False], [False, False], [True, False], [False, True], [True, False], [True, False], [False, False], [True, False], [True, False]][[False, True], [True, True], [True, True], [False, False], [False, False], [False, False], [True, False], [False, True], [False, False], [True, False], [False, False], [True, False], [True, False]]Failed
regression: scenario 4[[False, False], [True, True], [False, False], [True, False], [True, False], [True, False], [True, True], [True, True], [False, True], [False, False]][[False, False], [False, True], [False, False], [True, False], [True, False], [True, False], [False, True], [True, True], [False, True], [False, False]]Failed

SHA-256 / c129402abea46deb45e96e0ac1711e09fb412ae5798885aff206058c73200380

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(valve_type, samples):
    valve = False
    out = []
    for call in samples:
        if call is None:
            out.append([False, valve])
            continue
        want = (call == 'cool') if valve_type == 'O' else (call == 'heat')
        changed = want != valve
        valve = want
        out.append([not changed, valve])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 1',
   ['B', ['cool', 'heat', 'heat', None, None, 'cool', 'cool', 'heat', 'heat', 'heat', 'heat']],
   [[True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [False, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['regression: scenario 2',
   ['B',
    ['heat',
     'heat',
     'cool',
     'cool',
     'heat',
     None,
     'heat',
     'cool',
     'heat',
     'heat',
     'cool',
     None,
     'heat',
     'cool']],
   [[False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, True],
    [False, True],
    [True, True],
    [False, False],
    [False, True],
    [True, True],
    [False, False],
    [False, False],
    [False, True],
    [False, False]]],
  ['regression: scenario 3',
   ['O', ['cool', 'cool', 'cool', 'heat', None, None, 'heat', 'cool', 'heat', 'heat', None, 'heat', 'heat']],
   [[False, True],
    [True, True],
    [True, True],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [True, False]]],
  ['regression: scenario 4',
   ['B', [None, 'heat', 'cool', 'cool', 'cool', 'cool', 'heat', 'heat', None, 'cool']],
   [[False, False],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, False]]]],
 [['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: scenario 1',
   ['B', [None, None, 'heat', None, 'cool', 'cool', 'cool', 'heat', None, 'cool', None]],
   [[False, False],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 2',
   ['B', ['heat', 'cool', 'heat', None, 'cool', 'heat', None, 'heat', None, 'cool', None]],
   [[False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 3',
   ['B', [None, 'heat', None, None, None, None, 'cool', 'heat', 'heat', None]],
   [[False, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [True, True],
    [False, True]]],
  ['regression: scenario 4',
   ['B', ['heat', 'cool', 'cool', 'heat', 'heat', None, 'heat']],
   [[False, True], [False, False], [True, False], [False, True], [True, True], [False, True], [True, True]]]],
 [['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: scenario 1',
   ['B', ['cool', 'heat', 'heat', 'cool', 'cool', None, 'cool', 'heat', 'heat', None, None, 'heat']],
   [[True, False],
    [False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [True, True]]],
  ['regression: scenario 2',
   ['O', [None, 'cool', 'heat', 'cool', 'heat', 'heat']],
   [[False, False], [False, True], [False, False], [False, True], [False, False], [True, False]]],
  ['regression: scenario 3',
   ['B', ['cool', 'heat', None, None, None, 'heat', 'heat', 'cool']],
   [[True, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, False]]],
  ['regression: scenario 4',
   ['O', ['heat', 'heat', 'heat', 'heat', 'heat', 'cool', None, 'cool', 'cool', None]],
   [[True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True]]]],
 [['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 3',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'heat', 'cool', 'heat', None, 'heat', None, 'heat']],
   [[False, True],
    [True, True],
    [False, True],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [True, False]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: scenario 1',
   ['O', ['heat', 'cool', None, 'cool', None, None, 'cool']],
   [[True, False], [False, True], [False, True], [True, True], [False, True], [False, True], [True, True]]],
  ['regression: scenario 2',
   ['B', ['cool', 'cool', 'heat', None, 'cool', 'cool', None, 'cool']],
   [[True, False],
    [True, False],
    [False, True],
    [False, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False]]],
  ['regression: scenario 4',
   ['O', ['cool', None, None, 'heat', 'cool', None, 'heat', None, None, 'cool', 'cool']],
   [[False, True],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, False],
    [False, False],
    [False, True],
    [True, True]]]],
 [['regression: scenario 1',
   ['O', ['heat', None, 'cool', None, 'heat', 'cool', 'heat', 'cool', None, None, None]],
   [[True, False],
    [False, False],
    [False, True],
    [False, True],
    [False, False],
    [False, True],
    [False, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True]]],
  ['regression: scenario 3',
   ['O', ['heat', 'cool', 'cool', 'heat', 'heat', None, 'heat', None, 'heat', 'heat', 'cool', 'cool']],
   [[True, False],
    [False, True],
    [True, True],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [False, False],
    [True, False],
    [True, False],
    [False, True],
    [True, True]]],
  ['regression: O valve season change',
   ['O', ['cool', 'cool', None, 'heat', 'heat', 'cool']],
   [[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]],
  ['regression: B valve idle hold',
   ['B', ['heat', None, 'heat']],
   [[False, True], [False, True], [True, True]]],
  ['regression: first call heat on O',
   ['O', ['heat', 'heat', None, 'cool']],
   [[True, False], [True, False], [False, False], [False, True]]],
  ['regression: first call cool on B',
   ['B', ['cool', None, 'cool', 'heat']],
   [[True, False], [False, False], [True, False], [False, True]]],
  ['regression: scenario 2',
   ['B', [None, None, None, None, 'cool', None, 'heat', 'cool', None]],
   [[False, False],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [False, True],
    [False, False],
    [False, False]]],
  ['regression: scenario 4',
   ['B', [None, 'heat', 'heat', None, 'cool', None, 'cool', None]],
   [[False, False],
    [False, True],
    [True, True],
    [False, True],
    [False, False],
    [False, False],
    [True, False],
    [False, False]]]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: O valve season change[[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]][[False, True], [True, True], [False, True], [False, False], [True, False], [False, True]]Passed
regression: B valve idle hold[[False, True], [False, True], [True, True]][[False, True], [False, True], [True, True]]Passed
regression: first call heat on O[[True, False], [True, False], [False, False], [False, True]][[True, False], [True, False], [False, False], [False, True]]Passed
regression: first call cool on B[[True, False], [False, False], [True, False], [False, True]][[True, False], [False, False], [True, False], [False, True]]Passed
regression: scenario 1[[True, False], [False, True], [True, True], [False, True], [False, True], [False, False], [True, False], [False, True], [True, True], [True, True], [True, True]][[True, False], [False, True], [True, True], [False, True], [False, True], [False, False], [True, False], [False, True], [True, True], [True, True], [True, True]]Passed
regression: scenario 2[[False, True], [True, True], [False, False], [True, False], [False, True], [False, True], [True, True], [False, False], [False, True], [True, True], [False, False], [False, False], [False, True], [False, False]][[False, True], [True, True], [False, False], [True, False], [False, True], [False, True], [True, True], [False, False], [False, True], [True, True], [False, False], [False, False], [False, True], [False, False]]Passed
regression: scenario 3[[False, True], [True, True], [True, True], [False, False], [False, False], [False, False], [True, False], [False, True], [False, False], [True, False], [False, False], [True, False], [True, False]][[False, True], [True, True], [True, True], [False, False], [False, False], [False, False], [True, False], [False, True], [False, False], [True, False], [False, False], [True, False], [True, False]]Passed
regression: scenario 4[[False, False], [False, True], [False, False], [True, False], [True, False], [True, False], [False, True], [True, True], [False, True], [False, False]][[False, False], [False, True], [False, False], [True, False], [True, False], [True, False], [False, True], [True, True], [False, True], [False, False]]Passed

SHA-256 / 3a97a3563e6c1f203d1875f9431b9ccbb0805ed4ecf3b50603259506a0160004

Verification & scope

A deterministic bounded teaching model of one thermostat or HVAC controller decision evaluated per sample. Temperatures are integer tenths of a degree Fahrenheit unless stated otherwise. The contract is a stipulated toy convention, not a claim of conformance to any manufacturer, ASHRAE guideline or code. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:51:49.106738+00:00.

Case digest / 05265e4d03b96ec786d19d61597737bd08af8ad2aca19983560b1eccf1c7b375