Hi Effic Furnace vent Pipes covered with snow

[dannydee]

I just got a call from one of my relatives. They live quite a distance from me but I am familiar with their house because I once lived in it. Back when I lived there, the house had a traditional natural gas furnace that vented out the chimney. Two years ago they had a High Efficiency furnace installed.

The furnace vents out thru the sillplate, where the two PVC pipes exit outside. I know there are less than two courses of concrete block showing, so that means these pipes are a maximum of 14 inches from the lawn.

They have had extreme snow this winter and the woman has had to call in a furnace repairman 3 times, each call costing her around $150, and each time these pipes were buried under the snow. Each time she has nearly frozen to death because it always happens at night and she believes that she can not call during the night and must wait until morning. The woman is not in good health as it is, and she is unable to go outdoors, much less shovel snow. She has a caregiver come daily to help her, but they dont look at things like this. Besides that, the snow turns to a block of ice from the heat and moisture and requires lots of chipping to clear it.

Anyhow, she knows that I am handy and have done all sorts of home repairs. They told me she is really upset because the repair guy told her she could get carbon monoxide poisoning, and she must dig out the snow. She said she wishes she would have kept the old furnace that vented out the chimney.

While I am handy, I have not dealt with these H.E. furnaces, but I do know how they work and the way they put 2 pipes out the side of the house for intake air and exhaust.

Immediately after the call I got to thinking about extending the pipes higher up the house siding. I think they are too low. It would be easy enough to use a few PVC elbows pointed upware, add 2 or 3 feet of pipe, strap it to the house, and put some traps on top so the pipes dont fill with rain or snow.

The question is: Is this legal and acceptable?

If not, is there another solution? Putting an awning of sorts over the pipes might help keep some of the snow off the pipes, but there are limits on that due to blowing and drifting.

I'm sure this happens regularly, what are the solutions?

[Edwin Pawlowski]

The person coming out should have fixed this hte first time. The original installer was incompetant and should have fixed it right. The service man is a thief taking advantage of her.

That is what should have been done the first time. At the top all you have to do is put a "tee" so it is vented on two sides.

[The Freon Cowboy]

need to make sure that it doesnt exceed maximum length or number of elbows as stated in the venting table in the installation manual

should work other wise , or some body could go and dig them out every time it snows ,

[e-mail] wrote:

[ransley]

It was installed improperly, sure you could raise it or for now maybe put something over and around it to keep the snow from building up over that area. If the inspector saw it he would have made the Hack installer fix it which he should if he wasnt a crook. You could maybe still pull a permit to get the original installer cited to fix his hack. Or have him fix it and dont pay him.

[hallerb]

dont move it too close to any window that can open

[Jim Redelfs]

It won't help now but, in the future, she should hire an ETHICAL contractor. The [blocked intake] repair should have been dealt with on the very first visit.

For $150, the vents should have been cleared and the customer INFORMED of the need for a modification to raise them. That could have been done somewhat later for a modest fee.

Heck, the vents should have been installed HIGHER in the first place.

The repairman is a callous jerk. It's virtually impossible for the new furnace to emit CO when it is NOT RUNNING!! When it IS running, the exhaust vent fan MUST run or the system will shut down. Wotta @$$hole. :(

Despite the expensive bills recently paid for service on the new furnace, she will still enjoy smaller gas bills. It will now take a bit longer to "repay" the upgrade cost due to the unnecessary, additional service calls, but repayment will still happen. Tell her she did a good thing, regardless.

I chose to install ONLY the exhaust line, leaving the furnace to draw warmed combustion air from within the house. Yeah, I'm probably paying a bit more for operation but I am assured of fresh air in the house - and it still uses a LOT less air than the old one which was drafting warmed air up the flue ALL the time. Had this same technique been used on the woman's installation, we probably wouldn't be discussing it now.

The only thing that should be attached to the end of either pipe should be an elbow, vertically aligned with openings facing up and down, on the exhaust line. Even that is necessary only if there is still a CHANCE it may be covered with snow. If you raise the lines sufficiently, such "protection" SHOULD be unnecessary. My exhaust line simply has a wide-sweep 90 pointing down. Of course, it is 10-ft off the ground.

Find the installation manual for the furnace. It will specify the maximum run length and number of bends (elbows) allowed. If you comply with that, everything should be fine. Good luck.

[Bob F]

You will need to make sure that condensation inside the exhaust pipe can run out - you must not form a low spot where water will not flow either towards the furnace or towards the outside. If the pipe coming out is sloped downward, it must continue downward (or level - not upward) to the end of the pipe. If all parts of the exhaust from the furnace to the outside slope upward or level, then you can extend it upward. The condensation will flow back to the furnace and be pumped out through the condensate pump.

Extending just the intake pipe, which might solve this problem, would be less worrysome, as long as water cannot get into it via rain, sprinklers, etc.

Minimise elbows, and use larger radius ones if you can. Check the "installation manual" for exact limits. This document should have come with the new furnace, or can be obtained from the manufacturer. Check their web site.

[EXT]

While she may not be able to go out and shovel it clear herself, someone must then be shovelling her doorway, sidewalk and other access areas, pay a little extra to have them clear the snow from the vent, it has got to be cheaper than paying a serviceman $150.00 to shovel the area after freezing all night.

Also pay attention to the regulator on the gas meter, it should not be buried under snow or ice as it can cause the pressure regulator to start allowing the gas pressure to go too high at the appliances. This area needs to be shovelled clear on a regular basis. Check with your gas company if you don't believe me. I used to work for one before I retired.

[Bubba]

Your best advice would be to get the installation instructions for that furnace and follow the venting instructions "To The Letter". This will give you a very high chance of never having a venting problem if the instructions are followed correctly. Bubba

[HVACTECH2]

In all honesty Ed you really can't say that without seeing the job. The 90% or greater furnaces have pipe run limits. in some it's as little as 30 feet. also each 90 degree el is equivalent to 5 or 10 feet of pipe depending on the model. what if they are at or near the piping run limit? adding 1 90 degree el can cause major problems. what the OP needs to do first is get the manual for the furnce in question and check this.

[DerbyDad03]

I recently asked a simliar question over at

My question related to extending the pipe *horizontally* along my exterior wall just so that I didn't see the steam outside my kitchen window - more of an asthetic issue than anything else. The answer I got was a resounding No! due to the possibility of the condensation freezing up and causing problems. In other words, with more pipe exposed to the elements, I was asking for trouble.

[Jim Redelfs]

That's a good point. Now that I think about it, I have never seen more than a

12-18-inches exposed pipe.

[Edwin Pawlowski]

Agree on the checking the manual, BUT - - - -

If you live in an area that gets a good amount of snow, provisions must be made to eliminate the problem. If it happened once, it can happen again, and to not fix it correctly is negligence. If you are in the heating business you know about degree days, annual snowfall, low temperature expectations, etc. You design accordingly. If you can't, you are incompetent and should be bagging groceries.

[HVACTECH2]

Yes, I do agree with you there. My only point was that you can't just go throwing lengths of pipe and 90 degree ells in without knowing what you are doing.

[clint]

I have a 90%+ gas furnace that is vented with pvc pipe. We moved into a development 6 years ago. In the 2nd year there were 4 homes on our street of

8 homes that lost their heat due to snow that blocked the intake pipes. In all of the failed cases the intake and exhaust pipes were only 10 to 12 inches above the ground. I got the installation manual that was attached to the return duct on our furnace and it stated that in areas of significant snowfall the pipes (both intake and exhaust) should be extended to a height of 12 inches above the maximum anticipated snowfall. It showed how an 90 degree elbow should be placed where the pipes exit the building and pieces long enough to gain the necessary height placed into that elbow with another 90 degree elbow placed at the top pointing away from the building. Then a short piece of pipe placed into those elbows. Then a reducer and a smaller pipe was to be installed at the end of the exhaust pipe so as to create enough back pressure to expel the exhaust gasses away from the house and the intake pipe. The intake pipe had an additional elbow pointing down toward the ground. Then after all that is done the exhaust should be insulated and covered or painted to prevent UV damage. Fortunately the hack that was installing the furnaces (108 of them) was still working in the development and after a considerable amount of pressure he finally extended all of the ones that were too low. I was going to take him to small claims court and pay to have the pipes extended but what finally got him to relent was that the pipes were a code violation. Whenever a code says to follow the manufactures directions then those directions become a part of the code for that particular item. Watch for distances from windows and other exhausts. (water tank and drier vents) Hope this helps. Clint Stoner

[Bubba]

You havent said a thing that isnt in the installation instructions of every furnace. Other than the blithering part about sueing someone. Bubba

[Bob F]

And you know for sure that the O.P. has and has read the manual?

[Bubba]

I dont even know if the O.P. can read, Bob. Do you? Bubba

[Bob F]

No, but I do know that the reply you criticised made some very good points.

[Bubba]

And like I said..........What he replied was nothing that wasn't in the installation manual. You act as if he just wrote the book on it. That part about suing someone was just his blithering. He's obviously not gone through that. Oh, and you spelled criticized wrong. Bubba