[MiniMe4HVAC]

Hi guys

Would you please share from your experience what are the two parts of a furnace (any type any MFG) that fail most frequently?


Thanks
MiniMe

 

[pecmsg]

The Installer

 

[MiniMe4HVAC]

The Installer

You just failed :grin2: ....to answer the question.
So now a furnace comes with a built in installer huh?

 

[rider77]

No, he's actually telling the truth. Most residential furnaces are built pretty equal, some share the same parts.
Put one in wrong and you'll get failed heat exchangers and blower motor problems from duct issues, pressure switch trips from incorrect venting/combustion air, sooting from incorrect setup/LP conversions, clogged coils from lack of maitenance.
I guess hot surface igniters go bad more then anything.
I'd rather have a builders grade bare bones unit installed nicely then a top of the line peice of equipment hacked in.

 

[MiniMe4HVAC]

Neah... you are avoiding the question
YOU are the installer and you obviously installed many furnaces (so it is the same installer mostly, good or bad) so from the large number of installations that you have done so far a number of them had problems. Which part was involved?

 

[Bazooka Joe]

Here you go..... The oil filter and nozzle on a oil burner. You did not state what type of combustion.

 

[MiniMe4HVAC]

gas furnace ..damn it! I forgot that Sorry

 

[snupytcb]

It's a tough question. I guess the igniter but there are so many variables you can't say. for you it could be a blower motor, the next guy could be an inducer, it depends on install.

 

[Bazooka Joe]

Not including manufacture defects , Glow coil/ hot surface igniter /flame sensor ,spark igniter assembly being one , other things capacitors, power vent motor ( due to the surrounding high temperate of the flue gas ) and or power vent squirrel cage . if blower wheel of power vent is made of metal the corrosive flue gas tends to deteriorate and disintegrate the squirrel cage over time and bind up the motor.

 

[BaldLoonie]

What brand? Each one has a problem area it seems.

Probably pressure switches, many seem to be made in the same factory in Costa Rica and are dropping like flies in all brands that use them.

 

[MiniMe4HVAC]

I don't mind if you indicate the brand as well
I thought that due to construction principles specific parts are more exposed to problems than others
Igniters and their circuitry if they have any should be more exposed due to their functionality.

 

[pecmsg]

I put my boiler in 10 years ago. Knock on wood no problems.

I N S A L L E R.

A great system installed by hacks is garbage. Parts will fail.

A garbage system installed by a knowledge tech with the proper support

Priceless

 

[hvacvegas]

I don't mind if you indicate the brand as well
I thought that due to construction principles specific parts are more exposed to problems than others
Igniters and their circuitry if they have any should be more exposed due to their functionality.

Some of it has more to do with maint. also.

IE: An older unit with a dirty flame sensor, or a dirty filter, can tear through ignitors.
A high efficiency unit, if the drains back up, can go through pressure switches and/or ignitors.

Certain models had issues with heat exchangers.

Usually the older models get, the more common you find the same issue.
Sadly, you usually don't find out until after the unit is out of warranty.

 

[MiniMe4HVAC]

RE: older models -mine is an Olsen Duomatic that survived many of its yonger generations
I just had a look at the heat exchanger yesterday (since I opened the AC coil) and it seems to be healty and in good shape
I used one test that someone recommended me-make the room pitch black and use one of these

.
Stick the lamp deep into the burner and then look from above (high boy furnace). If you see any light then your burner is cracked. I could not see any.)
That being said I think that my furnace would rather die due to electrical parts...although those are very simple and still easy to replace

 

[snupytcb]

there is a more accurate method of that test but still is not reliable like modern tools are when it comes to combustion and hx's.

 

[Poodle Head Mikey]

The thermocouple and the fan/limit switch - especially the 11" version.

PHM
-------

Hi guys

Would you please share from your experience what are the two parts of a furnace (any type any MFG) that fail most frequently?


Thanks
MiniMe

 

[snupytcb]

The thermocouple and the fan/limit switch - especially the 11" version.

PHM
-------

well said. i am a little embarrassed to admit i kind of forgot about those parts. lol.

 

[MiniMe4HVAC]

It is interesting that none of you is saying "heat exchanger"

 

[hvacvegas]

Certain models had issues with heat exchangers.

.

 

[Linktorn]

You have to define the question more. Furnace? Part? Frequently?

My number one "no heat call", statistically speaking is flame sensor. It's not failed, just a lack of maintenance. That would be followed by thermocouples and igniters. This could also be chalked up to maintenance but it is a part failure. Then it goes into a mix match of motors, boards, pressure switches, limits (plugged filters), gas valves, thermostats, and various other parts. Another one not defined is water management varying from frozen venting, to plugged condensate lines.

I don't concider the heat exchanger a part. It's the furnace in my eyes. If it's failed, it's time for a new furnace. Even under warranty your just tossing good money away to keep your old junk furnace. I've replaced one heat exchanger this year. Homeowner wouldn't listen to reason. I did that in may. He's had two billable calls on that furnace since. One was last night at 3 am. Pressure switch. He was mad that he didn't choose a new furnace instead. I just smiled.

This is also assuming we are just talking residential.