On 13 Dec 2005 16:01:26 -0800, wrote:


Thanks for the info. The thermal expansion tank has a schraeder valve
on the bottom, so I assume it's the bladder type.

When I put a pressure gauge up to the tank it doesn't show any
pressure.

I tried to just push the valve in to see if there was water leaking
out, but it's dry.

So I plugged in a bicycle pump and tried to pump it up to 40 psi. But
as soon as I disconnect it and recheck the pressure it seems like it
hasn't "taken" any pressure.

Do you have to turn off the water and take the tank off to recharge it,
or can you charge it while it's in the system?

Yes, you cant have any pressure behind the tank while charging it.
Remove it. This will also give you a chance to inspect it.
Bubba