[peterthefish]

Just moved into our new home. I got bored and started reading the furnace manual since I’m not familiar with high efficiency or gas furnaces - I’ve only dealt with electric and oil (and coal at grandmas as a kid).

The install instructions state that the rubber coupling is to be used for the exhaust vent.

However, the install does not follow these instructions. The coupling is instead used for the combustion air intake.

The builder has told me this is a non-issue but he’s a... cut the corners kind of guy, to say the least. See the lovely microwave vent hookup.

Hoping to get a professional opinion on the furnace, as it seems to be a potential safety issue.

 

[comfortdoc]

The building inspector should catch that. It is not installed per manufacturers install instructions.

 

[ammoniadog]

Good question.

Personally, I would say those instructions make no sense and that your furnace is done the correct way.

If the rubber coupling is put on the pipe on the right (exhaust), it's not really accomplishing anything since the pipe is already well supported by the induced draft motor below it, and just passing through the black plastic deal without the rubber coupling seems to be more than enough to support it. The pipe on the left (intake) does not pass through the black plastic deal though. If you don't have the rubber coupling on that one then there's not much supporting the pipe other than the tiny 1/4" lip of that black plastic thing. Putting the rubber coupling on the intake pipe helps to support it better and therefore I believe that's the way it is really supposed to be.

edit.... I just read those instructions again and noticed that it says there is supposed to be some silicone and a tiny sheet metal screw holding the intake pipe into the black plastic thing. I still think that's pretty lame and that the rubber coupling would work better in that spot (instead of the silicone and tiny screw).

Any other United Technology guys have an opinion?

 

[beenthere]

Well, now it will be a bugger to change out the inducer if it ever needs to be changed out.

No harm to the furnace the way it is now.

 

[peterthefish]

Well, now it will be a bugger to change out the inducer if it ever needs to be changed out.

No harm to the furnace the way it is now.

Makes sense now - if done per diagram there’s no need to cut the vent to change the inducer, correct?

 

[ammoniadog]

No, I dont think the rubber coupling would have anything to do with making the inducer easier or harder to change no matter which pipe it's on. I just don't see the point of it being on the exhaust pipe though. In my opinion they should either give you 2 of them or zero of them. Or if it's really that important for it to be on one pipe vs. the other make it so it only fits on the black plastic deal that they want us using it with.

Come on Bryant and Carrier guys, what do you guys have to say?

 

[beshvac]

No, I dont think the rubber coupling would have anything to do with making the inducer easier or harder to change no matter which pipe it's on. I just don't see the point of it being on the exhaust pipe though. In my opinion they should either give you 2 of them or zero of them. Or if it's really that important for it to be on one pipe vs. the other make it so it only fits on the black plastic deal that they want us using it with.

Come on Bryant and Carrier guys, what do you guys have to say?

Yes it does if installed correctly. The pvc is supposed to be cut at the top of the black base. The rubber piece is supposed to be removable and connect the short stub from the inducer to the piping leading the way outside the house. Some day when the inducer is replaced a smart tech will cut the exhaust right at the top of the black base and move the rubber connector over. If it was done right in the first place, to change the inducer all you had to do was remove the rubber coupling and pull out the stub.

 

[comfortdoc]

That coupler supports the weight of the pipe resting on the rubber boot that is between the vent pipe and inducer housing. It also seals the cabinet, maintaining the integrity of the sealed combustion vestibule. The two piece install mentioned by beshvac would be the preferred method.

 

[pacnw]

Yes it does if installed correctly. The pvc is supposed to be cut at the top of the black base. The rubber piece is supposed to be removable and connect the short stub from the inducer to the piping leading the way outside the house. Some day when the inducer is replaced a smart tech will cut the exhaust right at the top of the black base and move the rubber connector over. If it was done right in the first place, to change the inducer all you had to do was remove the rubber coupling and pull out the stub.

Closer to correct, but still not totally correct!!
The install instructions are very specific and precise. The OP just did not post them to read.

The pipe going outside just sits inside the black square adapter and the rubber coupler secures the pipe and the adapter. This prevents condensation and flue gases from escaping.

The inducer has a rubber boots on it as well. The piece of pipe from the inducer to the black adapter MUST be glued into the bottom of the adapter!!!!! It will leak if not. The inducer end is secured into the rubber boot by a screw clamp.

The way to replace the inducer is to loosen the upper rubber coupler and remove the vent pipe, remove the four screws attaching the adapter to the furnace, loosen the inducer rubber boot and pull up the pipe from the inducer.

It is possible to just loosen the inducer rubber boot and remove the inducer without going through the entire process above. Some partial steps above make it easier.

 

[ammoniadog]

That makes sense guys. I stand corrected. I still think the factory should give you 2 rubber couplings but I'm guessing that aint gonna happen.

:cheers:

 

[pacnw]

That makes sense guys. I stand corrected. I still think the factory should give you 2 rubber couplings but I'm guessing that aint gonna happen.

:cheers:

We use Carrier.
They might, but I think not.
Not needed on the intake, nothing bad happens if it is not connected.
A screw is simple and cheap for the MFR.