On demand water heater help

This was my first one. Questions:
The fresh air intake was not sealed at the unit as well as sloping away from the unit before it went up through the roof, problem?

Exhaust vent has “trap” installed to catch condesate, 2 lines, small one drains to a little plastic tub, big one loops around and has water in the line but doesn’t go anywhere.

I think the answers are obvious, but take a look and see if you notice anything else.



Is that flue 0-clearance to the kraft paper combustibles :shock:
Properly secure NM in the background

This would be a suspect install with modified drain vent, clear vinyl tubing and Ziploc container…not to mention the previous moisture stained flooring…so what were your other concerns

Was there a pressure relief valve located about 6 inches down the hot water outlet pipe? If so, was it draining to the outside of the building?

If there was condensate coming down the flue, How long was the vent run? It should be no more than 25 feet in length. It might be that they didn’t have a cap on the vent outside and rain tends to enter the vent opening.


There is a TPRV as indicated however it was installed pointed at the wall another 6" away, no drain and nowhere to go.

Here is the stack.