Home Repair Forum

Need Advice · #1 (**permalink**) 01-31-2008, 09:42 PM

I have a Rheem Criterion Furnace, Model RGDG-10EAMER that has been giving me problems lately.
The burners will not always light. The igniter comes on and glows red hot, I can hear the sensor trip the value to release the gas to ignite, but there is not ignition of the burners. It will cycle and the blower will start but still the burners will not start. I have cleand the furnace checked the wiring and the IIBC board, the green light comes on to show there is power to the board. After tinkering with it for a while and vaccumming out the furnance and have turned off the gas and the value and the power swith to the furance and then turning it all back on it will light ( I think it has more to do with the time lapse of having everything tunred off and not any I really did), but it will run for the day and cycle several times throughout the day, but it eventually stop again and I go through the same process again and it will ignite again, but of course it will stop again until I go through the same steps. Any ideas of what is causing the problem?

HayZee518 · #2 (**permalink**) 02-01-2008, 07:22 AM

ok, you have a hot surface igniter. you may also have a millivolt generator to sense the pilot flame. -or- there may be NO pilot flame - just a flame rod to detect the presence of the main flame. check to see which type of flame sense you have. a flame rod senses a flame by the ionized gas between the rod and chassis ground. if the rod is covered with soot it will not work.

Need Advice · #3 (**permalink**) 02-02-2008, 03:30 PM

Thanks for your information. How can I tell if it is a Rod or a millivolt generator? I have read something about a flame rod before, but it said it would be in the last burner, I can not see anything in any of the burners ( not sure which one is the last one, or if I am looking in the right place. Is it in the part that delivers the gas or in the part in which the blame burns into? Can seam to see a rod in either place.) There is no standing pilot flame. There is only ignition when the igniter heats up and then gas is released to ignite the burners.

HayZee518 · #4 (**permalink**) 02-02-2008, 07:02 PM

ok, then judgung fromwhat you said the flame sense is a flame rod. the hot surface igniter is set close to the main burner. within a time delay period the igniter heats up and gas is supposed to be released. a flame rod is set close to but not necessarily within the flame itself. if your burner fails to light I would check out the surface igniter - its resistance has to be within engineered limits and the electronic control board for the burner.

mike n · #5 (**permalink**) 02-04-2008, 09:26 AM

I don't think the problem has anything to do with flame detection as you are describing the flame never lights are you actually hearing gas flow after the igniter heats up or are you hearing the valve click, describe the failure sequence again for me please and is it nat. or LP

Need Advice · #6 (**permalink**) 02-04-2008, 01:10 PM

The sequence is as follows. The burner will ignite for the day several times durning the day and then suddenly it will not ignite, in fact I believe after a while it does not even try to ignite any more. I have changed the filter vaccummed out the furnance and cleaned it up. In order to get it to ignite again, I turn of the the gas value that set on what in the old days looks like the old pilot light where you would have to turn it and hold it while lighting the pilot, in this case it is just a simple ON or OFF with electrical leads. I also turn off the main value (on the pipe) that goes to the furnace and I flip the electrical switch to off. After it sits for a while, I turn on the gas value in the furnace the gas value leading to the furnace and then the electrical swith. The igniter heats up and you hear the value click (no sound of gas being released) the burners don't ignite and the igniter goes off and it cycle through this few more times and nothing. After letting it for a while longer I try the same process and it will light and will continue to ignite for the day until suddenly once again it will not ignite and the process begins all over.

This is furnance that burns natural gas.

Thanks for your input!

HayZee518 · #7 (**permalink**) 02-04-2008, 01:41 PM

I have a propane gas stove that did the same thing you described. My problem was that the igniter leads weren't making a good connection. The hot surface igniter would glow but the main valve would not open at all. I took out the igniter and squeezed the connector as hard as I could and it worked a fw more times then quit completely. It got red but the main valve would not open. I bought a new igniter and installed it and it fired up immediately. This was five years ago and it's still working.

mike n · #8 (**permalink**) 02-14-2008, 10:11 PM

When you say that you hear no gas that tells me to look there so if you have a meter you can check on the two or three wires going to that valve, if there are two wires easy just check with your meter set to volts ac when the hot surface ignitor is glowing good and red you should read 24 volts across those two leads if you do and no gas is coming out your gas valve is sticking if there are three wires it is a little trickier you have to find the wire to the pilot valve and the common the other valve will be for main gas same deal about the voltage if you dont have 24 volts and no safeties are open then you may have a bad control board or wiring connection you need to follow the wiring back to make sure no loose connection.