furnace vent gurgling

jeffeg

Bought this house about 2 months ago and the furnace vent pipe gurgles. the furnace is a 90% Amana 70k BTU 3 ton airflow with induced air.

in the picture you can see the 2" PVC exhaust vent is sloped towards the elbow and I can hear the condensate being blown around in there.

If the vertical pipe slipped an I can push it up an inch, that would be the easiest...but...

To repair, I was thinking about 1) disconnect the vent pipe from the furnace via the rubber coupling 2) using a hacksaw and cutting the vent pipe about 10" above the elbow 3) cutting off what is necessary to properly slope the pipe towards the furnace 3a) cleaning out all the PVC shavings 4) putting it back together with a coupling. 5) hooking the pipe back up to the furnace.

My questions are:
1) anything wrong with the above?
2) any special glue I should use, or is standard PVC cement sufficient
3) if I wait until Spring to do this, what would be wrong with that.

thanks!
Jeff

Attached Thumbnails

 

ben's plumbing

you have the right idea make sure the whole pipe run is sloped back to furnace ....if you leave it go it will at some point shut down ..repair it now ...or it will leave you in the cold...ben sr

HVAC1000

I would suggest using Christy's Red Hot Blue glue. I love the stuff because it seals pipe nicely. But any PVC cement would work well

Legacyairsystem

undo pipe at rubber, take off an inch or two of pipe with saw at bottom, tighten it up, check your slope, no glue needed

hvac benny

I think you're looking at the picture sideways.

HVAC1000

I would cut pipe about 5 to 8 inches above elbow, cut off an inch or two then marry the two raw ends with a no hub rubber coupling and make sure the horizontal solidest back into the furnace. The rubber coupling farther up on the pipe make certain repairs easier in the future

HVAC1000

If you really wanted to get fancy too you could replace that 90 elbow with two 45 elbows

jeffeg

Thanks for the advise on the no-hub coupler - it helped a lot, I don't think I would have been able to make a PVC coupler work (see picture.)

there's not much play in the pipe penetrating the roof, so it would have been difficult getting a slope with a rigid coupler.

note: this is a horizontally mounted furnace. there is about a 1" per foot slope back to the furnace because I ended up flipping the pipe around (i.e. the hoizontal became the vertical and vice-versa, it fit better this way, if I shorten the horizontal pipe, I start to lose the slope again.

I thought this was going to be a lot easier than it was...

notice that it's not a clean fit on the no-hub coupler, but it is secure and does not leak vent gas.

??? my question-- is the cock-eyed fit on the coupler a problem? If it is a problem, can I wait until it warms up before I trim a little off of the horizontal pipe?

Any other solutions if what is in the picture is a no-go?

thanks a lot everyone,
Jeff

Attached Thumbnails

 

HVACTECH96

As long as condensate can drain back to furnace it should be ok.

HVAC1000

from what I can see it all looks good. the cock-eyedness of the pipe is fine as long as the PVC is fully inserted into the coupling and it is screwed down tight and is not leaking at all. i am glad that the no hub worked well for you, they are such a quick and convenient repair solution

carmon

Illegal here... not to code ..... I see nothing wrong...hope it works out....

HVAC1000

its perfectly fine to do that here as long as its not leaking. canada has different regulations and much stricter enforcement so it all depends on where Jeffeg is from. the only issue (around here at least) is some damage to your personal pride for not having straight lines. personally I would make it straight to make it look professional but thats not saying Ive never left things like that in my beginning days.

jeffeg

Thanks for the feedback... I agree, it does look sloppy... my problem is the vertical pipe going through the roof doesn't have much play, so it's going to be difficult to get any slope, 2" pipe isn't very flexible, but it could be better - I was looking around this evening - would it be OK to use a PVC flexible elbow?
like this one -> http://www.homedepot.com/h_d1/N-5yc1...1#.UOp4sXf5WQ4



as far as leaks, I just went by feel - air flow, heat and condensate -

should I check the joints with soapy water?

thanks. these forums are great!
Jeff

carmon

that clamp should not leak...as far as an flexible elboe you posted....definately not here... maybe you are allowed in your area...not sure....

hvac benny

I would have used two 45's instead of the 90. The first 45 would be right after the pipe left the unit, eliminating most of the horizontal pipe, and allowing the vertical pipe to remain straight.