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SOLVED! OFF TOPIC - Any HVAC Furnace experts here?? I need help!!
MDG
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- Marc
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I've had similar happen on two occasions, once when we first moved into our then new house and then again when we replaced the furnace.
The first time the issue was intermittent, and nobody could figure out what was happening. After having different techs look at it each time it failed, I was at a loss. then one night when it wouldn't fire I started to just do what I shouldn't and just tried different things. At one point I pulled the intake plumbing out from where it entered into the furnace. There sat a nice big maple leaf. The reason the issue was intermittent was that the leaf had split in two down the spine Sometimes the two pieces would fall on top of one another allowing enough airflow. Other times the two halves would sit side by side completely blocking the inlet. Removing the leaf fixed the issue.
The second time with the new furnace the issue was caused by bad install of the exhaust pipe. There was a low spot in the pipe causing condensation to sit in the low area blocking the exiting airflow rather than draining back and being captured by the condensate system. This one became obvious when we started getting water in the pressure switch.
I doubt your issue is with condensation, but I would lean toward some blockage on the intake side. I agree with the suggestion that someone made of disconnecting the intake at the furnace to see if it fixes the issue. If you can get your hands on a plumbing snake I would run that out the intake and exhaust from the inside out to see if you can clear a blockage.
Good Luck
The first time the issue was intermittent, and nobody could figure out what was happening. After having different techs look at it each time it failed, I was at a loss. then one night when it wouldn't fire I started to just do what I shouldn't and just tried different things. At one point I pulled the intake plumbing out from where it entered into the furnace. There sat a nice big maple leaf. The reason the issue was intermittent was that the leaf had split in two down the spine Sometimes the two pieces would fall on top of one another allowing enough airflow. Other times the two halves would sit side by side completely blocking the inlet. Removing the leaf fixed the issue.
The second time with the new furnace the issue was caused by bad install of the exhaust pipe. There was a low spot in the pipe causing condensation to sit in the low area blocking the exiting airflow rather than draining back and being captured by the condensate system. This one became obvious when we started getting water in the pressure switch.
I doubt your issue is with condensation, but I would lean toward some blockage on the intake side. I agree with the suggestion that someone made of disconnecting the intake at the furnace to see if it fixes the issue. If you can get your hands on a plumbing snake I would run that out the intake and exhaust from the inside out to see if you can clear a blockage.
Good Luck
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Caliguy
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- Thread starter
- #66
thanks, the pressure switch test in the video just tell me real quick if it’s a bad pressure switch or a clog so I’ll know tonight if it’s related to exhaust/intake.
Both my pipes are white plastic piping so it’s not very easy to disconnect I don’t think, if pressure switches are opening and closing as they should, that leaves the board as the only culprit
FCCinAZ
Well-Known Member
Where on the Jeep is this located exactly?
In all seriousness, if your doing these types of diagnostics on your furnace with guidance from a Jeep forum then you may want to take pause. Carbon monoxide poisoning is no joke. I appreciate the can do attitude of the do it yourselfer, but a healthy respect for things that can kill you and your family is likely in order.
On second thought, did you check to see if all the fuses are seated?
In all seriousness, if your doing these types of diagnostics on your furnace with guidance from a Jeep forum then you may want to take pause. Carbon monoxide poisoning is no joke. I appreciate the can do attitude of the do it yourselfer, but a healthy respect for things that can kill you and your family is likely in order.
On second thought, did you check to see if all the fuses are seated?
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Caliguy
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- Thread starter
- #68
lol thanks. I find most jeepers to be DIY’ers or folk who aren’t afraid to get their hands dirty from all walks of life. Between the Jeep brain trust, and a gun forum brain trust Iv also cross posted, I’ll get this sorted out, even if I have to use my Jeep to haul it to the shooting range for all those who helped to take a few shots at it.Where on the Jeep is this located exactly?
In all seriousness, if your doing these types of diagnostics on your furnace with guidance from a Jeep forum then you may want to take pause. Carbon monoxide poisoning is no joke. I appreciate the can do attitude of the do it yourselfer, but a healthy respect for things that can kill you and your family is likely in order.
On second thought, did you check to see if all the fuses are seated?
21 Willys
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Mine is 1/2" PVC pipe coming out of the bottom of the furnace leading to the outside of the house.
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XX4XEXX
Well-Known Member
Being your knee deep in troubleshooting and now familiar with sequence here's some more insight however I would bet it's the PCB 99.9%.
The stat can infact send false signal to the PCB as the relays do act up on the SSM but its unlikely and I believe you swapped it out, I think you answered your question already. So try this...
At furnace disconnect G
At stat energize heat
At firnace visualize heat sequence and let fail on limit. If this works its the PCB and or flame sensor.
next..
At stat and remove it leaving sub base on wall
At furnace jump out R to W1 and G and watch heat sequence If it sequences correctly its the stat or short in wiring like a chafe. If it does the same PCB or sensor. This is if FAN starts 1st as mentioned.
NOTHING in this entire system will allow fan to run 1st in the sequence you mention other then the PCB or stat. Proof switches, sensors, nothing becuse of series as mentioned by previous HVAC member.
The stat can infact send false signal to the PCB as the relays do act up on the SSM but its unlikely and I believe you swapped it out, I think you answered your question already. So try this...
At furnace disconnect G
At stat energize heat
At firnace visualize heat sequence and let fail on limit. If this works its the PCB and or flame sensor.
next..
At stat and remove it leaving sub base on wall
At furnace jump out R to W1 and G and watch heat sequence If it sequences correctly its the stat or short in wiring like a chafe. If it does the same PCB or sensor. This is if FAN starts 1st as mentioned.
NOTHING in this entire system will allow fan to run 1st in the sequence you mention other then the PCB or stat. Proof switches, sensors, nothing becuse of series as mentioned by previous HVAC member.
Last edited:
XX4XEXX
Well-Known Member
This would not cause fan to run 1st prior to heat ign but would cause burner to light the fail. Faulty psi switch.
I believe he stated fan comes on 1stthen heat ign then fan off then heat shuts down failed on a safety
I believe he stated fan comes on 1stthen heat ign then fan off then heat shuts down failed on a safety
We have a Coleman furnace that did the same thing. I unplugged one of the vacuum lines that went from the vacuum pressure switch to the upper burner box. Solved my problem.
Beachcomber72
Well-Known Member
It’s located in the back seat seatbelt crevice directly behind the front passenger seat between the right there and hmm over here maybe and yet directly above the oh here it is section.Where on the Jeep is this located exactly?
In all seriousness, if your doing these types of diagnostics on your furnace with guidance from a Jeep forum then you may want to take pause. Carbon monoxide poisoning is no joke. I appreciate the can do attitude of the do it yourselfer, but a healthy respect for things that can kill you and your family is likely in order.
On second thought, did you check to see if all the fuses are seated?
And as far as threads lately have gone this has been one of the best work together share ideas and let’s make it happen for a fellow Jeeper in a long time. This thread would have never been seen in the off topic section but I get it…
and yes as you mentioned, the Carbon Monoxide stuff is a very real consideration to take.
sadly it’s probably going to end up being the steering stabilizer.
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