Just had a new gas (propane) furnace put in and it is leaking water. This water seems to be coming from a 2 inch pvc pipe labeled exhaust. While I know that combustion yields CO2 and H20, and have often seen water dripping from car tailpipes, I have never seen water coming from a furnace. What did they likely do wrong in installation that has caused this?
Didn’t get the drain set up right for the exhaust.
My gas furnace shares the a/c condensation drain. If you furnace was set up to drain properly, the leak could be due to a faulty joint.
Faulty valve. I had the same thing. I forget the exact valve name but it’s not an unusual breakdown. Might be covered under warranty.
The furnace has been there 5 days so I am sure it is covered. Where will I look for this valve. Likely something just came loose.
Should the exhaust vent pipe be tilted downhill slightly toward the exterior, so the water drips outside rather than back into the furnace?
Another cause of water, highly irrelevant this time of year - the cooler coils for my AC are right above the furnace in the air flow. Obviously cooling air causes condensation. The installers did not properly clean the interior and the drainage hole got clogged with crud. As a result the water on the cooler coils froze, then when the air conditioning stops, the ice all melts and (no drain still) runs out all over the floor.
Modern high efficiency furnaces recover waste heat from the exhaust, this produces quite a bit of water. The water should exit from a tube leading to the floor drain. If it is exiting from anything else get the installer to come back and fix it.
So I called the guy who installed the furnace and he said that when he was doing the installation he could not find a 2.5 to 2 pvc reducer and that what he jury rigged was not sealed. He asked me to get silicone sealer and apply it to the joint, and if that does not work then he will need to replace the entire exhaust pipe.
I have no problem with trying that. Does it sound plausible? Can I buy that reducer online (he said he went to four stores, and could not find it)?
And while I am here, what kind of sealant should be purchased. He suggested a good quality silicone caulk. Is there something better than that?
If water is leaking out of the exhaust, so is CO. Depending on the location, the water could drip back down into the furnace like it’s supposed to or it could just pool there until it causes a bigger problem (like a blocked exhaust) and shuts down the furnace (no harm done, there’s a sensor for that).
If that’s what he told you to do, I’d consider either calling back and asking for his supervisor if it’s a big company or calling the city and asking for a post instillation inspection if he pulled a permit. Things like this are exactly why you pull permits.
For the record, if the leak is small, you’re not going to die. Keep a few CO detectors around your house (but not right next to the furnace) and heed their warnings and you should be fine. But I’d still see what I could do about getting it taken care of today. Just sealing up the joint maybe the right answer but replumbing it may be the better answer. Hard to say without seeing it.
I’d have a BIG problem trying that. You presumably paid a *professional to have the thing installed properly. If he didn’t have the correct part, he should have hauled his ass down to Home Depot and bought it.
Tell him you want it fixed properly, and you want it done ASAP. If he dithers, stop payment on the check.
*I’m assuming you didn’t have your brother-in-law Earl do the installation here. If you did, its your problem now…
Thanks, I will heed that advice and get him over here to do it. It is not my cousin Earl.
Just out of curiously how much CO does a modern furnace produce? I know it is now very hard to kill yourself with a car.
I know CO2 is heavier than room air. How about CO? This furnace is in the basement, there is another in the attic. Which of the two is the more dangerous.
I was under the impression that CO (not CO2 that’s carbon dioxide) is about neutrally buoyant. The problem is going to be if it gets itself sucked back into the return system and distributed throughout the house.
From what I can find it seems essentially isodense with ambient air. It’s specific gravity is almost exactly that of Nitrogen. Fortunately, my furnace has an outside air intake. However, I will get this fixed ASAP. We do have a couple of CO detectors, and they are quiet.
No leaks in the returns anywhere? No returns anywhere inside your house? No connections between the ducting and the furnace where a little bit of air gets pulled in? What about where you slide the filter in? Does a little bit of air get sucked in there?
Either way, yeah, get it fixed.
!?!?!?!?!?!?!?!?!?!?!?!?
This guy is not a professional HVAC person.
You cannot silicone this. Unless you live in Timbuktu, that reducer was available in boodles of supply houses.
If you hired a legitimate HVAC company you got taken advantage. (wheres there’s smoke there’s fire)
If you found some shade tree yahoo to save a few bucks, all is well. you got what you paid for.
The more I think of this, the madder I’m getting.
This is ***unconscionable. ***
Would you accept your mechanic saying, “I couldn’t find a U-Bolt (an exceptionally common part) so I duct taped the exhaust to the chassis. I think it will hold.”
That reducer was 1000% necessary and there is no workable jerry-rig fix.
To give you a more pointed answer, almost all furnaces have a 2" outlet for exhaust. If the flue is long, or has a lot of turns, or has a lot of Btus, the manufacturer will specify that the flue to enlarged to 3".
There is a chart in the installation manual that specifies how this is done, including the limitations. (There are limits to how long the flue can be, number of fittings etc)
At any rate, if its a smaller furnace and/or a short flue you can stay at 2". No reducer needed.
If he blew it up to 3" however, a 3>2 reducer was absolutely 1000%, take-it-to-bank necessary. ***There is no other way to do this responsibly. ***
The furnace shouldn’t have been started, and he sure as hell shouldn’t be asking you to silicone it.
raindog
Licensed HVAC contractor.
ETA
I live in a small city (Dayton, Oh) and I’ll bet I could find that reducer in 40 places.
No kidding.
My guess is that he didn’t plan well and got on site and realized he didn’t have one so he jerry-rigged it.
Raindog, I appreciate the information. The guy I hired was recommended by a neighbor. I don’t really know anything more about him, although I am beginning to think that perhaps I should have hired someone else.