FA-92669 / HVAC thermostat control / Member archive

Auxiliary heat releases as soon as DM rises above its start point · case 04

The immersion heater chatters on and off around aux_dm.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Hydronic heat pump degree-minute controller, one sample per minute of [supply_temp, target_supply] in whole F. Degree-minutes DM accumulate supply - target each minute and are clamped to [floor, 100]. The compressor starts when DM <= start_dm and stops when DM >= stop_dm. Auxiliary heat starts when DM <= aux_dm and stops when DM >= start_dm. Decisions use the DM value after this minute's update. Return [DM, compressor, aux] per minute.

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.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: scenario 19	`[[-18, false, false], [-34, false, false], [-54, false, false], [-43, false, false], [-71, true, false], [-91, true, false], [-112, true, false], [-130, true, false], [-140, true, false], [-155, true, true], [-170, true, true], [-182, true, true], [-201, true, true], [-213, true, true], [-231, true, true], [-243, true, true], [-250, true, true], [-250, true, true], [-185, true, true], [-125, true, false], [-69, true, false]]`	`[[-18, false, false], [-34, false, false], [-54, false, false], [-43, false, false], [-71, true, false], [-91, true, false], [-112, true, false], [-130, true, false], [-140, true, false], [-155, true, true], [-170, true, true], [-182, true, true], [-201, true, true], [-213, true, true], [-231, true, true], [-243, true, true], [-250, true, true], [-250, true, true], [-185, true, true], [-125, true, true], [-69, true, true]]`	Failed

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