Strange Problem with My Furnace - DIY Chatroom

chenjijc · 10-31-2009, 10:30 PM

I recently had this strange problem with my gas furnance.

When I set it to heat and set the temperature higher than the room temperature, I heard the furnace was starting. After a minute or so, it went off. I climbed to the attic and saw a switch besides the furnace. It was on. I turned it off, then on again. The furnace started, then I saw the lighter became red, however, no fire started. The furnace went off after a minute or so. Then, I tried again, the furnace worked. The fire started, and the furnace worked fine all night.

The next day, the problem came back. I had to climbed to the attic, restarted the furnace a few times until the fire was lighted.

Can someone help me with this? I called a technician. He couldn't tell what was the problem, and wasted me $84 diagnostic fee.

Thanks.

Plumber101 · 10-31-2009, 10:54 PM

Let's start with brand and model

Then if this is a newer furnace check and see if there is an LED on the control board. Thee may be a site glass on the door of the furnace so you do not have to remove the door to see the LED.

Now if there is an LED then when the furnace is acting up look at the led and count the number of flashes instead of turning power off and on, reseting the furnace and lossing the flash code.

To me it sounds as if you are having a pressure switch proving problem

chenjijc · 10-31-2009, 11:01 PM

Thank you very much for your quick reply.

I am using an old furnace.
Age: 1996
Distribution Type: Forced Air
Furnace Type: Natural Gas
Manufacture: Carrier
Model: WeatherMaker 5000

Can you give me more info about this problem, and how to fix it? Thanks.

Plumber101 · 10-31-2009, 11:46 PM

Quote:

Originally Posted by chenjijc

Thank you very much for your quick reply.

I am using an old furnace.
Age: 1996
Distribution Type: Forced Air
Furnace Type: Natural Gas
Manufacture: Carrier
Model: WeatherMaker 5000

Can you give me more info about this problem, and how to fix it? Thanks.

Just like I said before you need to count the flashes instead of turning the furnace off and back on. When you do that you reset the control board and lose the code. We need to get the flash code to go forward. If the furnace is working then go back into the attic and look on the doors you should see a flash code chart. Look for the LED and get familure with the furnace so that when it does act up you know what you are looking for ahead of time.

Post results and then we can help you. Until then it's all a guess.

chenjijc · 11-01-2009, 12:07 AM

Yes, there is a glass and I can see the LED. It is now red. I raised my temperature setting, so the furnace act up, but I didn't see the LED flashing.

There is an instruction on the furnace. It says "to initiate component test, turn off the room setting, then short the R and C terminal". Is this what you suggest me to do? How can I do that?

Thanks.

Plumber101 · 11-01-2009, 12:14 AM

No

Look for a code chart. You may have to look pretty close. Sometimes they are pretty small print

Wait for it to act up and get a code.

chenjijc · 11-01-2009, 12:40 AM

Yes, I see the code chart.

The LED stays as red. Now the furnace seems working properly. Maybe that's the reason it is not flashing.

So, I will wait till the furnace stops working next time, then go upstairs to read the flashing code. Am I right?

Thanks very much for your help. I learn a lot.

Plumber101 · 11-01-2009, 01:18 AM

yes that's correct

Yoyizit · 11-01-2009, 12:39 PM

In the meantime it would help if you can find a way to bring on the problem. This also comes in handy for checking if a fix worked.

chenjijc · 11-03-2009, 09:17 PM

My furnace stops working again. I have checked the code. It is 21.

The service label says "Gas Heating Lockout - Control will NOT auto reset. Check for : - Stuck gas valve relay on control or miswire to gas valve circuit."

Can anyone help how to fix this problem? Thanks.

chenjijc · 11-03-2009, 10:57 PM

Quote:

Originally Posted by chenjijc

My furnace stops working again. I have checked the code. It is 21.

The service label says "Gas Heating Lockout - Control will NOT auto reset. Check for : - Stuck gas valve relay on control or miswire to gas valve circuit."

Can anyone help how to fix this problem? Thanks.

My furnace is Carrier WeatherMaker 8000, Model 58WAV Upflow.

Please help. Thanks a lot.

Houston204 · 11-03-2009, 11:33 PM

Verify that your furnace is properly grounded.

chenjijc · 11-04-2009, 08:05 PM

Yes, it stands straight. Any other suggestion? Thanks very much!!!

Houston204 · 11-04-2009, 10:41 PM

Verify that the romex ground wire to your furnace is actually connected and not broken.

chenjijc · 11-04-2009, 11:05 PM

Yes, I checked the wires and they seem connected.