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Part of water heater vent pipe is now sloped downward after furnace installation

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9.6K views 9 replies 7 participants last post by  Jreality  
#1 ·
I just got a new furnace installed today. The guys are coming back tomorrow to install the A/C condensor. I notice that the water heater vent pipe is not the way it used to be. There used to be, say a 1 foot straight section (or less) coming straight up out of the water heater. This section is now slightly slanted and 3 of the 4 tabs at the bottom of the vent hood are connected in the slots (all 4 used to be connected). Above the now-almost-vertical pipe, there is an elbow. and then an approximately 1 foot section that now slants DOWNWARD before it connects to the big T where the furnaces vent exists. There never used to be a section of the water heater vent pipe that sloped downward. It sloped upward before they replaced the furance. Is it really acceptable that this section slopes downard? (This is a natural gas water heater, and the furnace is a forced air natural gas furnace.)

Thanks,

Jeff
 
#2 ·
that is a must fix NOW!!!

you should seriously think about shutting that off until it is fixed.

gasses travel up and this could cause those flue gasses, including carbon monoxide, to vent into your house and cause illness or worse!!!
 
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#4 ·
Before and after pics would be nice!

sent from my Samsung Galaxy Note
 
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#6 ·
Take pics then shut it off. This can easily spill carbon monoxide into the room. Advise them since you no longer have potable hot water, the house is technically "uninhabitable" which means you'll have to move into a hotel and they will have to pay your full expenses until the house is repaired properly. Or, you can take your chances and wait for them to come back but regardless, the vent connector must slope upwards towards the chimney 1/4" per horizontal foot. All offsets must be properly braced and supported. Min. 3 screws per joint with seams up. If this is a 40,000 btu/hr input WH and the total vertical rise is less than 3 feet before the chimney then the connector pipe must be increased to 4" per the sizing tables in the code. If the draft hood will not stay put, it must be screwed down or otherwise made secure.

Tell them after they are done, you want a certified professional to perform combustion analysis to ensure proper venting and no spillage into the room. Also remind them the return ducts must be sealed for the first 10 feet back from the blower plenum so as to minimize the chance of backdrafting out the draft hood. If this room is small or enclosed, as to see the calculations for makeup air then have them test once done to ensure it works or make corrections as needed.

Lastly, install low level CO monitors in the home outside the bedrooms.
 
#7 · (Edited)
I got them to fix it today, so that it now is the way it was originally, with no exhaust vent pipes slanting downward. I had pics of the way it was originally, in case they were to argue, but I didn't take any pics of the way it looked yesterday.

I'm just glad they fixed it. The new furnace appears to be working fine, and no carbon monixide detectors have gone off. I'm not thrilled about the humming noise during the ignition phase of the new 58CVA furnace. I'm told it is the sound of the inducer motor running, but I guess I'll eventually get used to it.

I won't know until the Spring, whether or not the new A/C system (installed today) actually works. I have it in the contract that I get a free A/C startup in the Spring, including any extra needed Puron after the start-up. I don't like it that they will be paid in full before the A/C is started up and confirmed to work, but I guess I have no choice, as long as everything passes inspection, is that correct?
 
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