Rheem Natural Gas Furnace

[etz_cutter]

Model: RGDG-07EAUER

I have a gas furnace that I am trying to start up for the winter. It won't start up and I am trying to figure out where to start troubleshooting. The furnace last winter was giving me problems where it would run for a cycle and then shut down and not turn back on. If I reset the power it would continue with another heat cycle.

This year when I connected everything to fire up nothing happened when I set the thermostat. When I removed the IIBC cover I saw no status LED indicators (three LED's for this furnace). When I followed the flow-chart troubleshooting path the first place I came to was to check the LED indicator lights. If they aren't on then I need to replace the IIBC module.

Will someone please kindly direct my steps here? First is this the right place to start for troubleshooting? Should I be looking elsewhere first? I don't have the original manual to help guide me in this process.

Thanks in advance,

[hvactech126]

well your were starting in the right place with the led's, but the unit must be powered to the leds to flash. there is a door switch that you will need to push in with power on to the unit.

[etz_cutter]

Thanks for the response.

Yes, I have manually pushed the door interlock switch in as I am checking the IIBC control module. When the interlock switch is open, i.e the door is off, there is no power to the board. When the interlock switch is closed, i.e. the door is on, there is 120VAC to the board and no LED's come on. This is where I am at...

[HayZee518]

follow the circuit diagram either in the ladder diagram or the point to point diagram. there's got to be one glued somewhere on the furnace. you do know how to troubleshoot using a schematic don't you?

[hvactech126]

check for low voltage fuse and 24 between r and c