[jeffnc]

Where is the best location for an expansion tank for a home in Eastern North Carolina, where the plumbing is exterior? i.e. in the crawl space. It's mostly copper piping. None of it is insulated, and it has never burst due to freezing. I don't think pipes would ever freeze since they are so close to the floor in the crawl space. It's an older house with no expansion tank currently installed. The water heater was just removed from under the kitchen cabinet, and a new bigger one installed in an exterior utility room, but no expansion tank yet. The old tank was 38 gal and the new one 50 gal. The newer plumbing that has been done is in PEX (so it won't support the weight of the expansion tank by itself.) The house and utility room are made from cinder block, so it will be a slight hassle to install strapping to hold the tank, but no big deal. Is there any danger of the expansion tank freezing if it's installed in the utility room? How about if it's wrapped in insulation like the new water heater is? Should the expansion tank go under the crawl space instead?

 

[AllanJ]

The expansion tank can be anywhere with no valves between it and the water heater (or other appliance it is intended to protect). But inspectors prefer to have it above the water heater so they don't have to go looking for it to verify its existence.

An expansion tank should be supported by more than the pipe it is attached to. Should tampering or failure of the air valve result in its becoming waterlogged, it will become heavy.

All plumbing should be protected from freezing. For plumbing in exterior walls or otherwise near exposed areas there should be no building insulation between the pipe and the living space.

 

[jeffnc]

Yes, I understand it can be anywhere but I was wondering if there is any preference with respect to potential freezing temperatures. Obviously I don't worry about freezing in the water heater in unheated space, but I was wondering about potential freezing in the expansion tank. The crawl space would be a little safer in that regard, but I'd prefer the tank be near the water heater if it's a non-issue.