Carrier Gas heater not firing


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Old 02-03-07, 04:57 PM
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Carrier Gas heater not firing

I have a Carrier 58RAV gas forced air heater / ac unit. When the unit gets the heat signal (RW closed), it starts the inducer fan for 25s. Then when the igniter starts, I hear the control board click several relays and the inducer fan shuts off and the igniter shuts off. It shounds like it is losing power or something.

It usually gives me no fault codes when all this happens, but once I got a 31, which is the pressure draft safegaurd. I am not surprised I got this, because the inducer fan had shut down on that event, but the controller appeared to continue its cycle.

I have run the test mode a number of times and get no fault codes from the test. Everything seems fine. I have visually checked the pressure draft safegaurd and it always seems to work and trips the microswitch. I wiggled all the connections and everything to the controller board and inducer circuit seems good.

Before I order a new controller board, does anyone have any suggestions as to what I should look at next? This seems to be an intermittent problem. When I start looking at it for a while, it goes away for a couple of days. It's frustrating!
 
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Old 02-03-07, 08:10 PM
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You put a meter on the pressure switch to see if it drops out before the fan shuts down?

You remove the hose and blow into it to make sure nothing is caught on the other end?

How's the pipe outside?
 
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Old 02-03-07, 09:06 PM
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I just tried running it again and the pressure switch closes and stays closed until after the fan shuts off. I didn't check the flue or hose, because the switch is working.

I just remembered that in August I had a lightening strike close to my home and lost my garage door opener, satellite receiver and several other things. Now I wonder if this control board was damaged. I have another heater for the upstairs and it is the same. That one is working fine.
 
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Old 02-04-07, 05:42 AM
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Ok, if the pressure switch is staying closed the whole time, then I'd check the gas valve to see if you are getting power to it. Make sure the switch on the valve is ON.

If no power going to the valve, them it's back to the board not sending power. But make sure there is no tripped flame roll out or limit if they are in series with the gas valve.
 
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Old 02-04-07, 08:07 PM
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Now the system is only getting as far as running the inducer fan for 1-2s before it shuts off and acts as if nothing is wrong. The LED stays on solid. That's not long enough for the pressure switch to activate. I checked the low voltage circuit and it is rock solid. I ran a jumper across the heat call to make sure it wasn't the thermostat, but I still get the same thing. I checked the connections and all seems ok. I think I'm going to replace the board.

Thanks for your help.
 
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Old 02-06-07, 06:22 AM
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I had the same issue with my Carrier- it was the inducer motor would not reach the preset rpm, therfore not allowing the gas valve to open.
 
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Old 02-06-07, 10:25 AM
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I had a similar problem with my furnace and found the pilot orifice clogged up....cleared the orifice and the problem went away.
 
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Old 02-10-07, 07:43 PM
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I ended up installing a new board and everything seems to be working great now. Of course the problem started out intermittently, so I will have to give it a week or two before I am confident that the issue is resolved.

Thanks for the advise.
 
 

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