Also, look for blockages in the flue, and tighten any loose wiring. Check the pressure switch hose of your furnace for blocks or an improper connection. Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Turn off the furnace power and repair a short or replace the pressure switch.
After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.ĭecipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Turn the power off and check the thermostat for improper settings or connections.
Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. See lights a flashing count them flashesĪ sampling of various failure codes on a furnace: Any light flashin on the control board? If not then look for a small fuse blown on the board.
