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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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My RHEEM Criterion II furnace started out acting like the

Customer Question

My RHEEM Criterion II furnace started out acting like the others, I set the thermostat to above room temperature, the purge fan would start, the igniter would light, the flames would start, and after 5 seconds they would shut off and the cycle would repeat in about 5 minutes. I saw there were three similar sensors with small brown "buttons" in the middle, and each with two wires. Two of the sensors were on the far side from the igniter and surrounding the flame tube, and the third was right next to the igniter/flame tube. I wiggled the wires to each, and pushed in each "button" (about the size and shape of a thin dime), and each one "clicked". Now the furnace igniter won't light at all, but the main fan blows constantly. The "buttons" felt more like thermocouples than mechanical buttons. Any suggestions?
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

Do this. Turn power off to furnace and back on.This will reset board.Then call for heat and let me know how far in sequence it goes and if we get an error code at that point.

Inducer vent motor comes on

Pressure switch closes

Igniter lights

Burners ignite

Main circulating blower comes on

If furnaces fails anywhere in the sequence we should get an error code by blinking lights on the control board. Turn power off and back on, then call for heat.tell me how far in that sequence it goes and what error code is on first failure We will go from here.