I'm new to this forum, and the reason why I'm new here is because I have had three different "professionals" look at my system and they have come to three different conclusions.
What I have: Lennox 125,000 BTU Forced Air Furnace the model number looks to be G20Q3E-125-1. Motor HP 1/3. I have about a 2300 sq.ft house. It is a Category I Central Furnace. (All this by way of the stickers on the inside of the unit.
What I know:
When I push the new switch on the system and it starts up, the heat works great, it does a great job of circulating through the house, and all is fine and dandy.
it stops before it reaches the temperature on the thermostat, and therefore I have to push the switch again. It does not come on automatically.
Other notes, one of the three gentlemen held a carbon monoxide meter up to the system (after he said that there was probably a ton of carbon monoxide coming out of the system and that I shouldn't be in there because I would probably get a headache) and it read a zero change in CO both right by the backflow place as well as on the ground below the backflow place. Therefore I don't think that there's any CO being released and question his reliability.
The PSE&G guy came by and said that the system needed to be serviced by a chimneysweep. However, after flipping the switch today I ran outside and saw that there was heat being released out of the fake chimney that is up there (not my idea, I bought the house in July). And that there is not really any backflow as demonstrated by the third guy who held a match up to the backflow place and it looked like the smoke was going up it.
The carbon monoxide tester guy said that I had a cracked exchange and needed to replace the whole furnace probably next year sometime, the PSE&G guy doesn't want to see me until it's fixed and he can remove the red tag, and the last guy didn't touch anything and is still charging me a visit price which I will pay and will never use him again.
So, what I'm saying is while I don't have a lot of faith in the guys I've used so far, I just want a rough idea of what you guys feel the problem might be so that the next professional that visits and says what you guys thinks it is, I can hire him on the spot and trust his judgement.
Thanks for your help in advance and I'm sorry for the novel...I shoulda been a writer...
What button are you pushing.
And is this the Furnace with the little damper door over the burners?
Beware of advice given by some guy on the Internet.
if you are pushing the switch down by damper, probably cracked heat exchanger. if switch up on side of flue box probably flue issue.
yea Lynn g20 has damper door
I think it's called the limit switch. If the little door that swings down is called the damper door, then yes it is. Inside it I can see what looks like 5 metal cones if that helps. It's open now right even after the furnace just turned off.
what town if in south jersey
Also, after reading more on these forums, it looks like there could be soot as well in the backflow place.
I am in Ewing, NJ (which is pretty close to Trenton, NJ)
i don't go that far north, are any of the dealers that looked at it lennox dealers? i would get a local lennox dealer in to take a look. i would not be resetting it any more, guy with co detector may be on right track. if heat exchanger is cracked it may still be under warranty.
I'm going to have to write down which furnaces are which.
I'd say don't push the button again until someone figures out whats happening.
Beware of advice given by some guy on the Internet.
Where exactly is the switch that you are pushing?
It sounds like you are reseting a rollout switch. If a rollout switch is tripping, that is a bad thing.
It could be as simple as needing a good cleaning. If the heat exchanger is sooted up, it may not be drafting properly, so fire can roll out into the burner compartment, causing the rollout switch to trip.
Usually if the heat exchanger on one of those furnaces is sooted up, it was likely caused by a crack/hole in the heat exchanger allowing air to blow into the heat exchanger and disturb the combustion proccess, causing the soot. Fire could also be getting blown out into the burner compartment, causing the rollout switch to trip.
Those furnaces had the "dura curve" heat exhanger. If you do a search on this forum for "dura curve", you will find that lots of people find lots of them cracked.
You need to find an honest competent tech to diagnose the problem. It sounds like you are having dificulty finding that though.
The switch is to the side of the backflow place in the 3 inch or so gap and it is attached to the backflow place with a hole drilled in it (about 3/4 to 1 inch in diameter). It has two bolts that attach it to the backflow place. The backflow place only has a little soot almost like a dusting rather than a layer. The switch has two cords with funny looking connectors that slide over the pieces that are sticking out of the switch.
I reiterate that it works just fine for about 5 to 10 minutes and then shuts down but does not turn back on again which is why I didn't think pushing the switch in to turn it back on was a problem. Thanks to the people who have given their advice here I have stopped that behavior.
I'll look for dura curve and see if anyone mentions a problem similar to mine...maybe that will help.
As a novice I don't know these things, but couldn't it be the thermostat isn't working properly and calling for the furnace to turn back on at the correct temperature. I'm a civil engineer so I understand systems, just not your guys and gals type of system.
I still have hope of finding a honest and good tech though...I'm heading to the yellow pages and looking for Lennox.
if switch is the one towards the top of the furnace it may be a chimney problem. go to lennox.com you can put in zip code and do a dealer search. thermostat could not cause your problem.