Expansion tank that can handle more heat

CBRob

A home that I manage has a poorly placed expansion tank, it's on the cold side of the tank but close to a recirc pump that keeps it too hot.

I'll probably try to put a little heat trap loop before the tank but I'd like to know if there are dhw tanks that can handle more heat

JUGHNE

How do you know it is getting too hot?
Most true DHW exp tanks are rated for pretty high temps.

Zman

DHW expansion tanks can handle more heat than the occupants or the relief valve. What are the symptoms?

CBRob

Just replaced it last year and it is full of water already.
I'll take a pic tomorrow of how it is situated
I'm guessing the failure is heat related...
Could be something else.

STEVEusaPA

What’s your incoming water pressure?

CBRob

I have not put a gauge to it, but there is a regulator with a 65psi high end.

JohnNY

DHW expansion tanks are typically factory pre-charged to 40 PSI. Isolate and pump up your tank's air pressure. Problem solved.

DZoro

What model of tank are you using? Is this on the domestic water? Boiler water? There are differences between DHW tanks and Radiant heating tanks.
D

CBRob

John was right, I just needed to pump it up.
It's at 50 psi now and holding air.

CBRob

DZ,
I found the tank on the radiant heat was incorrect... same house.
Swapped in a rx30 .

Also noticed the circ pump installed with a vertical shaft, but I think that is ok with adequate psi in the system. I saw another discussion here at heating help that talks about pumps installed incorrectly

CBRob

Can I use the flex2 dhw tank that I removed in another dhw application?
It's not fubar from being exposed to glycol?

Jamie Hall

CBRob said:

Can I use the flex2 dhw tank that I removed in another dhw application?

It's not fubar from being exposed to glycol?

No. Once it has been exposed to glycol, you mustn't use it for domestic (drinking) water.