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.
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.