Gas and Oil Home Heating Furnaces - New Carrier furnace problem
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Mopar1
01-18-06, 11:47 AM
This spring I and my brother in law installed a new 93% effecient carrier furnace and A/C unit. The A/C works fine but the heater will not ignite with the front inspection cover on. At first we thought that the PVC chimney was too small so we added 3" inlet and outlet with a 3" concentric on the roof. We have tried the restricters in the inlet and outlet pipes. It is a 100,000 BTU propane furnace, 2 stage that we had to change over from natural gas. It ignites and runs just fine with the cover off. When it is running and I install the cover on it the flames seem to back out of the burn chambers a little. Thank you for your help and I hope I have given all the info needed.
Jay11J
01-18-06, 01:27 PM
Your brother in law a Carrier dealer?
If he is, I'd call them back under a warranity call.
Sounds like it either a bad heat exchanger or poor piping of the venting.
Did they follow the install manual for pvc sizing?
If he is, I'd call them back under a warranity call.
Sounds like it either a bad heat exchanger or poor piping of the venting.
Did they follow the install manual for pvc sizing?
Mopar1
01-19-06, 06:55 AM
No, my brother in law is an HVAC guy but he works on large industrial units. He got it through his place of employment.
The inlet and exhaust is 20' a piece long and has 2 90* elbows and 1- 3" to 2" reducer and 1 90* 2" elbow per side.
This is more than ample for the length of pipe used per the manual.
The inlet and exhaust is 20' a piece long and has 2 90* elbows and 1- 3" to 2" reducer and 1 90* 2" elbow per side.
This is more than ample for the length of pipe used per the manual.
Jay11J
01-19-06, 07:42 AM
Ok. if the flame works with the cover, off. and not when it's on.
You take a reading on preasure switch to see if that is not closing whenn the covers are on?
If the switch is not closing, then I think it may be a bad inducer (Not stong enough to pull the flame in the heat exchanger) or have you tried removing the exhaust pipe at the furnace and see what happens?
You take a reading on preasure switch to see if that is not closing whenn the covers are on?
If the switch is not closing, then I think it may be a bad inducer (Not stong enough to pull the flame in the heat exchanger) or have you tried removing the exhaust pipe at the furnace and see what happens?
Mopar1
01-19-06, 08:06 AM
Ok. if the flame works with the cover, off. and not when it's on.
You take a reading on preasure switch to see if that is not closing whenn the covers are on?
If the switch is not closing, then I think it may be a bad inducer (Not stong enough to pull the flame in the heat exchanger) or have you tried removing the exhaust pipe at the furnace and see what happens?
We did not take a reading as far as I know. The flame will stay lit if I put the cover back on it after it is already burning but the flame changes like it backs out of the burner tubes a bit. Or kinda like it gets fatter so it hits the sides of the tubes insted of going just through the center if that makes sence.
I have tried removing both the inlet and exhaust and installed the cover and tried to light it. It did not light but it did fill the room with highly explosive propane/ air mixture so I won't try that again! :)
The inducer motor starts in high speed and after the burner lites it slows down. I have removed the motor and fan to see if there was anything wrong in there but did not see anything that looked suspicious.
I have wondered if there is a defect in the heat exchanger causing to much resistance to flow that it won't let it draw through the intake pipe. How would you find out something like that?
You take a reading on preasure switch to see if that is not closing whenn the covers are on?
If the switch is not closing, then I think it may be a bad inducer (Not stong enough to pull the flame in the heat exchanger) or have you tried removing the exhaust pipe at the furnace and see what happens?
We did not take a reading as far as I know. The flame will stay lit if I put the cover back on it after it is already burning but the flame changes like it backs out of the burner tubes a bit. Or kinda like it gets fatter so it hits the sides of the tubes insted of going just through the center if that makes sence.
I have tried removing both the inlet and exhaust and installed the cover and tried to light it. It did not light but it did fill the room with highly explosive propane/ air mixture so I won't try that again! :)
The inducer motor starts in high speed and after the burner lites it slows down. I have removed the motor and fan to see if there was anything wrong in there but did not see anything that looked suspicious.
I have wondered if there is a defect in the heat exchanger causing to much resistance to flow that it won't let it draw through the intake pipe. How would you find out something like that?
Jay11J
01-19-06, 09:32 AM
My guts are telling me it's the heat exchanger.. Your brother in law's company a carrier dealer?
If he's not. I will amost will say that the warranity is out the door. ??? Unless he can clame it in?
No way to really test it with out taking out the heat exchanger or calling tech support.
I am afraid there is not much more I/we can do here for you.
If he's not. I will amost will say that the warranity is out the door. ??? Unless he can clame it in?
No way to really test it with out taking out the heat exchanger or calling tech support.
I am afraid there is not much more I/we can do here for you.
Mopar1
01-19-06, 10:22 AM
Thank you for your information. I will talk to him to see what can be done about an exchange or something. That is some real bad news for me!
Jay11J
01-19-06, 11:21 AM
That's a big down fall when you get a "deal" on something, and you may not get any support on it.
That's why we stress let the Pro do the job. Not getting stuff on line or though a buddy where they may not be able to get warranity support.
That's why we stress let the Pro do the job. Not getting stuff on line or though a buddy where they may not be able to get warranity support.
Mopar1
02-09-06, 08:36 AM
New update:
My brother in law had removed a solid metal baffle in the burn box up where the air enteres into it. He thought that he had read in the manual that he neded to do that. He went back to find that info but he could not find it.
He came by saturday and put one back in there and it has worked fine ever since!
I guess that the air must have been flowing too fast where that plate should have been causing the flame to stop traveling over to the other burners. :wall:
Yes, it pays to have someone do the job right the first time!
My brother in law had removed a solid metal baffle in the burn box up where the air enteres into it. He thought that he had read in the manual that he neded to do that. He went back to find that info but he could not find it.
He came by saturday and put one back in there and it has worked fine ever since!
I guess that the air must have been flowing too fast where that plate should have been causing the flame to stop traveling over to the other burners. :wall:
Yes, it pays to have someone do the job right the first time!
Jay11J
02-09-06, 03:40 PM
Thanks for the update.
Yeah, the baffle is there for a reason.. Glad to see you are up and running.
Yeah, the baffle is there for a reason.. Glad to see you are up and running.