I have a Rheem Criterion gas furnace. It runs fine and has been serviced recently. They were not able to solve this either.
The furnace runs fine on a heat call, but then the fan(main blower) will run after the flame is out. I know it is supposed to do this at the end of the heat call for cool down, but this is not that. When I open and close the door, tripping the lockout, it fires up again with flame and can then run for some time without doing it again. 2 green LED's are lit when in normal operation, but only 1 is lit when this occurs. Bad Board? Gas valve? very intermittent but not trustworthy. I could leave home and the fan could run all day doing nothing.Flame sensor has been replaced along with the ignitor. Please help!!!
I didn't leave your question posted in that other thread. Doing so means double replies and questions.
The fault codes should be listed on the back of the blower door.
I believe what you are seeing is a one hour lockout code.
That means a fault had happened.... probably several times and then the board locked out.
That furnace blower is timer controlled from the control board.
You need to reset the furnace and watch it until failure to get the actual fault code.
Your furnace may have code storage.
I need the full model number for that or the part number off the control board.
The furnace model is on the ID tag inside on the side wall near the burner.
Hi Pete;
Thank-you so much for the reply. the only problem with trying to watch when it fails is that it can go for a day or so before it does it again. I have heard it happen when in the room, you can hear the flame go out. When I look through the site glass (that I had to install) I see 2 led's lit when running/normal/off. When it fails and is just blowing air, 1 LED is lit (the power LED) the one that is out has an "ok" label. I will get the stuff you asked for. I do have some pics of the board, I will try to post them here. Here are some #'s off the board: 1012-823, 922613,
thanks again for all of your help.
this is my board. Should I replace it or is it something else?
I have a Trane XB80 furnace and a 5055-3797 White Rodgers control board where the flame keeps cycling on and off. I checked the high limit on the control board and it is reaching the limit and the limit switch is turning the flame off while the blower and the exhaust fan continue to run. It waits a while and then turns back on when it cools off. Is this normal or is the limit switch bad?
[h2][color=#333333]Hello Experts - I have[/color]
[color=#333333]- Carrier MVP100-F-18120 furnace[/color]
[color=#333333]- Furnace Control board - HK42FZ0220905.[/color]
[color=#333333]- Thermostat control unit - Ztech ZCV2.[/color]
[color=#333333]- Two zone control[/color]
[color=#333333]My system has stop working yesterday. I thought the control unit was bad because the temperature schedule control was not working since summer time, but the unit was working fine with the temperature control. A couple days ago, I noticed something weird going on. My AC turns on in the middle of the night (thermostat was not set it to run at that temperature), and the furnace was not running sometimes even though the thermostats was set it to run. It stopped working completely yesterday. I went and checked the Ztech control unit, and it seems to have the correct status from the thermostat. It calls the heater to run, and I checked the output voltage (24VDC) on the Ztech unit. I also checked the output to the damper, and it has the correct voltage of 24VDC. It looks to me the Ztech unit is working fine. I opened the access panel of the furnace, and I see the status code was blinking. Read through the instruction from the panel, it looks like it is error code "24 - Secondary Voltage Fuse is Open." I checked the fuse, and it is not shorted. The instruction says to replace the furnace control board.[/color]
[color=#333333]My questions are[/color]
[color=#333333]1) is the furnace control board bad?[/color]
[color=#333333]2) is the Ztech unit need to be replaced?[/color]
[color=#333333]3) what would be the replacement part for the furnace control board? Are there any cheap compatible board ?[/color]
[color=#333333]Thank you!![/color][/h2]
12-28-21, 12:53 PM
