Where to terminate an abandoned vent pipe for old power-vented hot water heater?
Andrew C| Posted inGeneral Questionson
Michigan, Zone 5.I am replacing an old power-vented hot water heater with an electric water heater.
Question: where, and how, should the abandoned vent pipe be terminated?
The water heater is in the basement. The power-vent goes straight up through the first floor (behind walls), thru the attic, and out the roof, terminating in a downward hook.
我应该剪掉在阁楼年代吗omewhere above the insulation level and just cap both ends of the tube? Cut it off in the basement near the ceiling and cap it there?
Should I leave the roof termination as is? [That’d be preferable, because it’s a really steep roof, and technically it’s outside of my control as it’s a condo.]
Thanks,
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Replies
Andrew,
I'd leave the roof cap termination alone. They can remove it when the roof is redone - hopeful some years from now. If it's easy, cut the duct close to the underside of the roof and seal the end. Otherwise cap it at the ceiling of the room it comes from.
Cutting it in the middle is potentially risky, lest somebody think it's still complete and hook up another burner to use it at some future point. If you're going to do that it's better to pull it all out and just cap the it a few feet below the roof terminator kit.
Otherwise, capping it at the bottom-only is fine. There will be a tiny heat leak due to convection in the pipe, as well as a bit of conducted heat loss, but the total energy cost is miniscule as long as it's capped.
"Cutting it in the middle is potentially risky, lest somebody think it's still complete and hook up another burner to use it at some future point."
I really good point I didn't think of.
Thanks Malcolm and Dana,
Capping it at the bottom only in the basement/mechanical room sounds like an easy option; I'll do that.