Can't get new Rheem gas furnace to fire up model RGRM-10

jdemaris

I am NOT a heating/HVAC person. Electrician, yes. I just tore out an old oil hot-air furnace in an farm-house I own and replaced it with a new Rheem RG10 upflow gas furnace (with propane fuel). I can't get it to fire up and Rheem offers no tech support. Any help will be greatly appreciated. This is a two-stage, 95% eff. furnace. I installed the propane conversion kit. Installed a new two-stage thermostat. Hooked it all up to what seems right to me. It made some noise at first - and sounded like a blower going. Went back off after a few seconds and after that -nothing. The circuit board has two lights lit. No blinking. The "power" light is on constantly and the "status" light is on constantly.
I followed the trouble-shooting chart in the install manual and now am at a dead-end.
It states . . .
#1 - If the "status" and "power" lights are on steady - go to the next step
#2 - check voltage at the IDM (induced-draft motor). I did and NO power
#3 - check wires/connectors between the IDM and IFC. I did and all it tight
#4 - Ensure line-voltage between P2-2 and P2-3 on IFC (integrated furnace control. This one has me stumped.
I see nothing on the board marked P2-2 and P2-3.

Any ideas where to proceed?

Tinman

Did you bleed the air out of the gas line?

jdemaris

No, I did not bleed it. I assumed (perhaps wrongly so) it would bleed itself. But . . at it is - the furnace does nothing. Can air in the gas line cause this sort of thing? Better said - even if I DID bleed it now - since the furnace does nothing - how could it even sense gas in the line? It DID do something when I first turned it on - but it was in the basement and I was upstairs by the thermostat. I sounded like the induction blower that ran a few seconds and stopped. Since then - absolutely nothing and I don't see anything that can be "reset." On manual reset switches are up at the burner and they are all fine.

lchmb

interrupt power to the unit to clear a lock out...

bmwpowere36m3

I'd start by purging the line, first kill power to furnace (service switch or breaker), crack open the gas connection at furnace and wait till you smell gas. Then do up the connection and turn the power back on.

Set thermostat so it calls for heat and try again.

Tim McElwain

Do not crack open the gas line that is dangerous.

P2-2 and P2-3 are terminals on a six connector or nine connector or twelve connector white block on the Integrated control. Depends on the board as to how many. Get a bright light and a magnifying glass and you will see numbers on the block or better yet use the diagram that should be on the unit or in the manual.

Brp814

You mentioned that you were an electrician, is the furnace properly grounded? Today's furnaces require a good ground. Also check the polarity of the line volt. Hot to hot and neutral to neutral. Try this also, just jump out the "R" and "W" on the board, does the furnace start up? If not then it is something else Keep us posted on what you find.

bmwpowere36m3

*Disclaimer*

I'm no expert… but I think dangerous is a relative term. That is exactly how the gas company purged my boiler when they came to hook up the meter.

Either you purge the line or reset the furnace and try again… as many times as necessary till it sucks thru all the air.

Granted it could "dangerous" if there's open flames, devices that can spark and/or lack of ventilation. Proceed with caution and common sense.

This is assuming its air in the line and not an electrical problem.

JUGHNE

With the condensing furnaces I am familiar with and have worked on, the first that must work in the inducer fan motor and it gets its power from the control board.

With the power and gas off you could unplug the inducer motor and hot wire 120 volt to the motor. It is most likely a 2 speed so just apply power to the white neutral and the black (high speed). Motor shud run. Then power up the white and red (low speed). Motor shud run slower. Then that proves the first step. (don't power both red and black at the same time or you will need a new inducer motor! for sure!)

Then with power on work back towards the control board to see if it is supplying power to blower. Jumper the 24v R & W to eliminate the t-stat as an issue. All of the grief I have had with any of these control systems is the sequence of ignition after the indurcer is running. I don't know of any limit which shuts out the inducer on start.
An item that is too simple would be the blower door safety switch not closed, but then there would be no indicator lights.

I don't believe the furnace even knows if there is gas there or not. I would leave it off untill I get the fan to run and prove the pressure switches and get the HSI to glow. Then shut power off and turn gas or and restart.

Tim McElwain

All purging of gas should be exited to outdoors never into the building. Any gas man who told you that or showed you that should be fired. I worked as a gas service tech for 10 years and was a supervisor for 18 more and have been an instructor on gas since 1994 until the present. Lighting equipment takes patience and always safety first.

Batch1026

Check your grounds and proper polarity. Make sure you have 24v. From there jump R to W. Your inducer should start, pressure switch closes then gas valve will open, then ignition. Call your local distributor for tech service. Here on Long Island we install Rheem and they have great tech service from MCN supply house.