Expantion tanks

C.M.

I have an old dual temperature system that uses an open expantion tank located in the top of the system.This tank is old and leaking,need to be replaced very fast.I,m not sure how to size the new seald tank(blader type)to accomudate the excess water that you get in your system when you go from heating to cooling mode.Thank you.

Constantin

Depends on a number of factors, no?

I second the adoption of a sealed expansion tank. Sizing them depends on the volume of water in the system and the ΔT the system experiences. Amtrol has a Extrol sizing chart, presumably that's good for most brands assuming the tanks have similar internal construction and size.