HVAC Refrigeration Guide — limit switch

Williams Wall Furnace Won't Light? Diagnose & Fix It

Jul 29, 2026

Williams wall furnaces run on millivolt control — no circuit boards, no flash codes. When a pilot won't hold, the unit short-cycles, or the thermostat stops responding, the fix is almost always a single OEM part. This guide walks through the four most common failure points — spark electrode, limit switch, millivolt thermostat, and blower motor — with diagnostic steps and confirmed Williams part numbers for each.

Tags: Blower Motor, Heating Repair, HVAC Troubleshooting, Limit Switch, Millivolt Thermostat, OEM Parts, Pilot Light, Wall Furnace, Williams, Williams Furnace Parts

Heil Quaker Furnace Flashing a Code? Here's What Every LED Pattern Actually Means

Jul 12, 2026

Heil Quaker/ICP furnace flashing a fault code? Decode the LED sequence, find the failed component, and get OEM parts that fix it right the first time.

Tags: Comfortmaker, control board, furnace repair, furnace troubleshooting, Heil Quaker ICP, HVAC diagnostics, ICP parts, inducer motor, LED flash codes, limit switch, no heat, OEM parts, pressure switch, Tempstar