Water heater & washer emergency drains = holes in the house
In my area the plumbing code requires a washer sit in a plastic pan, and that the pan have a drain draining direct to the outside. The pan drain cannot drain to the sewer system under the theory that if the washer overflows it is because the drain is clogged, so you need to drain the overflow elsewhere.
They require similar for a tank water heater – sits in a pan, and the pan has a direct drain to the outside. Note this is NOT the T&P valve drain on the water heater, it is the pan drain.
Seems like it would be simple, although unsightly, to install a small trap at the exterior and then manually keep the traps primed to prevent air leaks. (Presumably no water will ever go through these drains unless there is an overflow, so nothing to auto prime the traps). Short of that, is there a backflow preventor that can be used for this situation? It would need to be weak enough to allow water with only some head pressure to flow out, and strong enough to resist air going through it.
While both of these are small 1″ drains, this creates two 1″ holes in the house. I have never read of this issue on GBA. What are people doing to prevent these two drains from being total airleaks in an otherwise tight house?
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