Gas water heater down draft

[rollerdawg]

I also have a radon mitigation system installed which runs all the time. I suspect this might be further adding to the negative pressure problem.

Jim

[HayZee518]

If your house is really tight for heating there's inadequate combustion air in the basement, that's why you are getting the negative pressure. Open a window or provide some kind of ducting around the furnace area from the outside.

[rollerdawg]

I just had a mason install a 3" aluminum duct inside the flue all the way to the top of the chimney. This was supposed to take care of the venting problem because the hot gas would have a smaller diameter flue to heat up and would create an updraft more quickly. Supposedly, even the heat from the pilot light would continue to keep an updraft in the flue. Well it still doesn't work (and it cost me $1000). There is still a very strong down draft created in the flue (especially on very cold nights) and it takes at least several minutes for the draft to reverse direction when the water heater is calling for heat.

Can a draft inducer fan be added to the top of a conventional hot water tank? I guess I probably should have considered changing my hot water tank to a direct vent or power vent type with make-up air being supplied from outside. Probably would have cost me less $$ and would also have solved the fireplace problem.

[HayZee518]

if your house is totally sealed against air infiltration, then you would see a downdraft. for gas appliances in a basement, makeup air is ALWAYS needed. Crack a window or put in an outside to inside vent.