Natural gas water heater - backdrafting

[Mke_Nate]

While tidying up in my basement, I noticed some of the plastic plugs on top of my natural gas water heater showed signs of heat deformation. This problem seems to have appeared since we spent time on air sealing, insulating, and making other energy efficiency changes.

Looking around, I discovered our house (built in 1929) does not have a make-up air inlet. I plan to remedy this shortly.

The water heater's exhaust passes through a couple of bends and finds its way into the lined chimney. Beyond adding the make-up air vent, is there anything I should change with the flue pipe on this installation? It appears the water heater was, at one time, electric and that this unit was a replacement some time ago.

Thanks again,

Nate

 

[John Gayewski]

If you could get the run shorter by moving the heater or perhaps take one of the bends out of it and have it run straight into the chimney that is about all you can do to the vent to make it better.

It appears you have a large enough space are you sure you need an inlet.

 

[Sponsor]

 

[Mke_Nate]

If you could get the run shorter by moving the heater or perhaps take one of the bends out of it and have it run straight into the chimney that is about all you can do to the vent to make it better.

It appears you have a large enough space are you sure you need an inlet.

Thanks John, that is helpful advice. I'll try first to straighten out the run and shorten to the extent that I can.

 

[Reach4]

I would lay a piece of steel over that plug to spread the heat out.

 

[Tuttles Revenge]

We had a similar event at a clients. Turned out that the aluminum chimney liner had oxidized so much that the aluminum oxide dust had completely plugged the liner at the base where it turned out of the chimney.