Expansion tank help

Thanks for all the help in the last few weeks.

Hopefully one last question.

1992 house, no expansion tank off the hot water heater. The house does have a pressure regulating valve, but no backflow that I can find (I think the PRV acts as one?). I am installing a new water heater, should I install an expansion tank even though the house has never had one, and never had any water come out of the check valve in the previous heater? I am using PEX, how do I support the tank with plastic plumbing (it will be on a wall in the garage)?

Thanks,

--Brian

water pressure

what kind of water pressure do you have??

over 90psi? Its still nice to instal one.....


lots of places have nominal pressure and
probably dont need one....

you could go either way....


as far as supporting the tanks....

if you have the room on the side of the heater
you can simply get some metal pipe strapping
and some small sheet metal screws and strap the tank to the side of the water heater....then plumb to it...

or strap it up to the 2x4s near by...and plumb to it...

Yes, install a Exp. Tank. Use copper for the first 3' or so coming out of the hot and cold from the heater then transition to PEX. You can install the tank and ball valve on the copper.

Be sure the tank and ball valve are on the cold (street side) of the water heater.

Like MPM said
If the tank is installed horizontally support the tank with strapping to the joist above.

It seems that homes that never had an expansion tank, need one when the wh is replaced. The only explanation I can come up with is that the burner size and efficiency of todays WH are somewhat larger and better that 15 years ago. So the water gets heated faster and hence the expansion problem occurs. If water heated slowly, the system "absorbs" the increased volume, but when it is heated fast, the pressure increases too fast

Wow ...

... you guys are the best. I will be working on it tomorrow, will let you all know how it went.

Thanks a ton,

--Brian