Does anyone here know anything about furnaces?

[grampi]

Our furnace was installed new 6 years ago. It's a Coleman model TG8S080B12MP11A. Our HVAC guy who installed it claimed it was an awesome furnace (his words). Well, he was wrong! This is the most unreliable POS I've ever seen. Every winter we have to deal with this thing constantly going out on us. It has a light on the main circuit board that flashes rapidly when there's a fault to indicate what the problem is. It goes out quite regularly because of the flame sensor, which is nothing more than a wire that sets inside the combustion chamber. I can take this sensor out and clean it and then it will work for a while, and then it starts faulting out again. Even replacing the sensor with a new one only works for a week or two before it starts faulting. When it goes out, the furnace runs constantly, blowing cold air, and wasting electricity. Last year we had to have the main circuit board replaced because we kept getting an error for an open limit switch, and now I'm getting that error again too. With my work schedule that has me away from home for 2 weeks at a time and my wife here alone, and temps lately being in the single digits, I can't have an unreliable furnace. Do I have any other choice other than having to replace the entire furnace?

 

[turtlevette]

A real engineer would bypass all that extraneous stuff. That what I did on my hot tub to get it really steaming hot.

Do you have schematics?

Just a wild guess. The flame is too rich and carboning up the sensor.

 

[dishdude]

Originally Posted By: turtlevette
A real engineer would bypass all that extraneous stuff. That what I did on my hot tub to get it really steaming hot.

Do you have schematics?

Just a wild guess. The flame is too rich and carboning up the sensor.



Yikes! I won't set my hot tub higher than 100.

 

[NHGUY]

I had no idea Coleman still made furnaces.We had a Coleman floor furnace in the early 70s and it was a noisy,smelly POS.

 

[Jetronic]

maybe the flame IS going out?

oil or gas? check the supply of either is constant. oil could be gelling, esp if kept outside or in a unheated room. Gas pressures can drop if the neighbours are all starting their furnaces around the same time (coming home from work?)

 

[Garak]

Has the board ever been replaced? Is the sensor being reinstalled correctly and is it OEM? For some of our industrial stuff, the flame sensor has to be placed just so, and OEM boards and flame sensors make for a much less problematic time. There are some generic parts out there that, while substantial cheaper, just don't give the performance in the long run. And Jetronic makes a good point about the gas supply.

 

[Pop_Rivit]

Coleman (at least that model) is a re-branded York. If you can't find an HVAC person who knows them well enough to fix it correctly, then if I were in your shoes I'd simply replace it with a reliable unit. Around here, we have a service company that inspects the furnace each fall and, if it fails for any reason during the winter, they pay for the repair. If you have a company in your area that offers something similar you might also consider that route.

Originally Posted By: turtlevette
A real engineer would bypass all that extraneous stuff. That what I did on my hot tub to get it really steaming hot.


Good idea! Bypassing the safety features on a furnace is really a fantastic idea, and a stroke of sheer brilliance!

 

[Donald]

You need to get a good HVAC guy or a service contract and let them deal with it.

 

[grampi]

Originally Posted By: Jetronic
maybe the flame IS going out?

oil or gas? check the supply of either is constant. oil could be gelling, esp if kept outside or in a unheated room. Gas pressures can drop if the neighbours are all starting their furnaces around the same time (coming home from work?)


Natural gas

 

[grampi]

Originally Posted By: Garak
Has the board ever been replaced? Is the sensor being reinstalled correctly and is it OEM? For some of our industrial stuff, the flame sensor has to be placed just so, and OEM boards and flame sensors make for a much less problematic time. There are some generic parts out there that, while substantial cheaper, just don't give the performance in the long run. And Jetronic makes a good point about the gas supply.


The main board was replaced last winter due the open limit switch errors, which are back again. When I replace the sensor, I install it the same way the original one was installed, and they are OEM.

 

[grampi]

Originally Posted By: Pop_Rivit
Coleman (at least that model) is a re-branded York. If you can't find an HVAC person who knows them well enough to fix it correctly, then if I were in your shoes I'd simply replace it with a reliable unit. Around here, we have a service company that inspects the furnace each fall and, if it fails for any reason during the winter, they pay for the repair. If you have a company in your area that offers something similar you might also consider that route.

Originally Posted By: turtlevette
A real engineer would bypass all that extraneous stuff. That what I did on my hot tub to get it really steaming hot.


Good idea! Bypassing the safety features on a furnace is really a fantastic idea, and a stroke of sheer brilliance!



He'll probably get electrocuted in his hot tub...

 

[grampi]

Originally Posted By: Donald
You need to get a good HVAC guy or a service contract and let them deal with it.


The guy who installed this furnace came highly recommended and is a licensed HVAC guy...since he recommended this POS, I'm gonna see if I can get him to replace the furnace for the price he pays without any markup. I think it's the least he could do since I've had problems with this unit every winter since it was installed...

 

[spackard]

There are probably enough youtube videos to allow you to troubleshoot it yourself, if you have the ability and time.

https://www.youtube.com/watch?v=rBCW3qYjtr0

So, this one says low airflow (replace filter) is one cause. A failing switch is another problem.
Another is too high gas pressure, but you'd need a manometer to check, which is about $40 for a Chinese clone.

Respect the safety controls. The thing has to operate 24/7/365 both in normal and abnormal modes. All those things are on there for a reason.

 

[AZjeff]

Originally Posted By: grampi


The main board was replaced last winter due the open limit switch errors, which are back again. When I replace the sensor, I install it the same way the original one was installed, and they are OEM.


In your OP you say you've had problems every winter since you got it. If you've had trouble every winter since it was new hopefully you've documented the service calls and can show a pattern? In the quote above you say you replaced the sensor. The problem could be if you've been doing some of the troubleshooting and replacing parts yourself. Quick seach looks like Coleman has a 10 year parts warranty? Your highly recommended HVAC guy should be going to bat for you, he recommended this unit. If he can't figure it out he's not as good as you thought.

 

[bullwinkle]

If you have an adjustable speed blower, a temporary fix might be to set the fan switch to "on", which causes the blower to run continuously at high (A/C) speed. Sounds a lot like it wasn't installed properly, or something is restricting airflow somehow (blocked filter, blocked air returns, etc.). Don't go bypassing stuff, could lead to a fire, or (if you're having ignition problems), even an explosion. Get a pro out there!

 

[Doog]

Originally Posted By: grampi
Originally Posted By: Donald
You need to get a good HVAC guy or a service contract and let them deal with it.


The guy who installed this furnace came highly recommended and is a licensed HVAC guy...since he recommended this POS, I'm gonna see if I can get him to replace the furnace for the price he pays without any markup. I think it's the least he could do since I've had problems with this unit every winter since it was installed...


Try calling a different Coleman furnace guy

 

[BigCahuna]

Seems like having fire is against his furnace's theory of operation. No much chance it's gonna heat up anything. Having a wood stove might be a good backup plan.,,,

 

[NormanBuntz]

If your furnace is a rebranded York, it's no wonder. Many of their units have been made overseas for years. My most trouble prone HVAC system ever was a York. No more York for me--I switched to Trane. No problems since on two new Trane systems.

Remember that some contractors recommend certain products when they get great deals on the units because the units have been discontinued or because the units just plain stink and aren't selling well. Like others have said, if you don't want to replace it, a local service contract may be your best bet.

 

[Gillsy]

Originally Posted By: grampi
Originally Posted By: Garak
Has the board ever been replaced? Is the sensor being reinstalled correctly and is it OEM? For some of our industrial stuff, the flame sensor has to be placed just so, and OEM boards and flame sensors make for a much less problematic time. There are some generic parts out there that, while substantial cheaper, just don't give the performance in the long run. And Jetronic makes a good point about the gas supply.


The main board was replaced last winter due the open limit switch errors, which are back again. When I replace the sensor, I install it the same way the original one was installed, and they are OEM.
My money says, bad design, or tech that is lacking. I vote for a new tech, get his opinion, and go from there. Good luck! I woke up to twelve below this morning.

 

[yeti]

Originally Posted By: grampi
Originally Posted By: Pop_Rivit
Coleman (at least that model) is a re-branded York. If you can't find an HVAC person who knows them well enough to fix it correctly, then if I were in your shoes I'd simply replace it with a reliable unit. Around here, we have a service company that inspects the furnace each fall and, if it fails for any reason during the winter, they pay for the repair. If you have a company in your area that offers something similar you might also consider that route.

Originally Posted By: turtlevette
A real engineer would bypass all that extraneous stuff. That what I did on my hot tub to get it really steaming hot.




Good idea! Bypassing the safety features on a furnace is really a fantastic idea, and a stroke of sheer brilliance!



He'll probably get electrocuted in his hot tub...


reading turtle's posts in the last couple of months led me to believe that, at some point, natural selection would come into play. his above post reinforces that opinion.

turtle -- no toasters in the hot tub!
when he dies, mr. brady, and 1 or 2 bitogers, might miss him. I, and our group, will miss him, since he gave us so many laughs. keep up the funny posts.

o.p.-- before you try to work out a deal with the service guy, think about getting another competent guy to look at it. possibly, it could be something minor, that is an easy fix. food for thought.

pop's post pretty much nailed it.
have a good day, all.