Tankless Water Heater: Install Inside or Outside?

LESLIE: Charlie in Texas has a question about a water heater. What can we do for you today?

CHARLIE: Yes. I’m looking at replacing my water heater with a tankless water heater and as I understand, it needs to be installed outside near the gas line from the meter and …

TOM: (overlapping voices) OK. It doesn’t have to be; it could be outside or inside. If it’s inside, of course, it has a direct vent to the outside or it could be installed outside, as well.

CHARLIE: Right. They said the best way would be to put it outside near that gas line. But my question is, we’ve had a lot of cold weather – unusually cold weather here in Dallas this year – and with that water – cold water line going outside the house, is there any chance that that could freeze?

TOM: (overlapping voices) Right.

CHARLIE: Should I worry about a problem with freezing?

TOM: No. All the water lines are insulated and the units that are mounted on the outside are usually freeze-protected. Now, that said, typically in a really cold climate, you wouldn’t install it outside because there’s a big system loss. But for Dallas, where you just may have the unusually cold snap, I wouldn’t worry about it; I think you’ll be fine.