Water Heater Drain Pan Pipe to Outside.. ?

Old 11-27-23, 10:56 PM
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Water Heater Drain Pan Pipe to Outside.. ?

Our house is built on a slab with the main living space one level above- so the garage/basement (at ground level) was originally unfinished. We recently finished the ground level so there is now living space beyond the garage. The water heater is in the garage right next to the wall going toward the living space, and also right next to an exterior wall. In the years before we finished the ground level the water heater failed once and flooded a portion of the garage. Now that we have living space right next to the garage I would like to protect against a possible future water heater failure (I plan to proactively replace the water heater- but you never know).

My plan is to add a drain pan under the water heater (see blue lines in pic), and connect the pan via some kind of flexible (green in pic) line (in case a replacement water heater changes position slightly) to a pipe (PVC?) that penetrates the exterior wall and then drops down on the outside as a drain.

Any tips on what flexible piping I could use to connect to the pan? And any tips on the best way to stick a pipe out through the exterior wall?

Or any comments in general on this plan?

Old 11-28-23, 05:35 AM
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Any kind of pipe that can withstand hot water can go through the wall and any kind of hose that can withstand hot water can connect the pan to the wall pipe

This is an unpressurized gravity fed line so there is no need to withstand pressure.

Suggest half inch inside diameter minimum. If the line is less than 1 inch, add some size changers and/or gender benders to the outside end to provide a 1 inch opening to put a bee excluding mesh over.

Optional: If you are paranoid about the water heater's failing and overheating the water at the same time the tank springs a leak you would select materials that can withstand 220 degrees F.otherwise 130 degrees is adequate.
Old 11-28-23, 05:57 AM
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I would use standard PVC. You don't need flexible because if the water heater moves, you've got bigger problems like an earthquake. But there is flexible PVC you can use though it's not stocked by most home centers or plumbing suppliers. You might have to look at pond or hot tub suppliers.

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