Working on a Coleman Evcon natural gas furnace in a mobile home not lighting / igniting. The circuit board has an LED flashing once indicating ignition failure. Thinking maybe a bad igniter or something. Any troubleshooting guidance greatly appreciated. Thinking I need to remove this to get to igniter?
I removed the assembly and think it may be one of these two devices. The heating element doesn’t have continuity so expect it’s the culprit. The other appears to be a spark starter.
That appears to be a Hot Surface Igniter (long "flat" device) in the top picture. It gets hot (cherry red) and ignites the burner. It should have a resistance of 30-75 ohms. If it's open, that's your problem. The smaller, round device is the thermocouple, which lets the unit know that the pilot is lit. If the thermocouple goes bad, the pilot will light as long as the pilot button is depressed, but will go out when it's released.
Replaced the igniter and it started working again for about a day. It’s flashing ignition failure code again. Is there a way to test the thermocouple? I probably should have replaced it as well while I had it apart. I’ll be diving back in this morning.
It looked like the hot surface igniter was cracked in your original picture.
I have a feeling it is/was ok and you have a control board problem.
You replaced the igniter and got the same problem.
You need to see if the furnace will light and fail or won't light at all.
If you don't see the igniter come on.... you need to check the 120v to it when it should be lighting.
If you don't get that voltage... the board is at fault.
If the burner lights but goes out in a few seconds... you probably have a dirty flame rod.
It's that metal rod with the yellow wire. clean it with a green Scotchbrite pad. It's just a stainless steel rod. It won't go bad unless the ceramic is cracked.
Remember.... those hot surface igniters are as fragile as glass and will crack if you bump them on anything. I'm a pro and have broken them during installation.
I replaced the flame detector with a generic one. It was straight down had to bend it to mimic the original one. We appear to be back in business now. We’ve been running a while with no issues. Thanks for all the input!
I replaced the flame detector with a generic one. It was straight down had to bend it to mimic the original one. We appear to be back in business now. We’ve been running a while with no issues. Thanks for all the input!
Looks good. Make sure flame rod is fully engulfed in the flame and it can't touch metal.
The flame must create a bridge between the flame rod and the metal burner.
Clean and keep the old rod for a spare. They don't go bad. I've never had to change one.
I have a Weil Mclain GV-5 series 1 gas fired boiler. I want to replace the boiler fed indirect tank with an electric hot water tank to allow me the benefit of the recently installed solar panels. The gas bill keeps going up and our electric bills are locked in at a minimal cost. Can I cap the feed and return lines feeding the Indirect tank and disable aqua stat
[img]https://cimg0.ibsrv.net/gimg/www.doityourselft.com-vbulletin/640x480/img_1233_5822__7eab3eb38ba7b5cbfae00610182aa2d77f17dee4.jpg[/img]
[i]Weil Mclain GV-5 with Indirect[/i]
relay for the indirect We have 4 zones with dedicated circulating pumps.
Hello all,
I am trying to wrap my head around a Goodman furnace issue. Natural gas, upflow configuration. It turned really cold here yesterday and it was enough for a lurking problem to rear its head. I noticed that the furnace was running, but not producing heat. I popped the access cover off to inspect the burners and inducer. Furnace fired right up. I thought it was a fluke so I put the access panel back in place and the flames went out. Now, as long as the access panel is off the unit it fires and heats normally. I am thinking there is a problem with the inducer, but I am stumped as to why the furnace operates normally with the panel open, but shuts the gas off as soon as I seal up the compartment with the panel. Any ideas?
12-20-22, 08:56 AM
