Replace/Rebuild Expansion Valve when Replacing Water Heater?

[jtdonohue]

I need to replace a 15 year old electric water heater. The supplies are plumbed with PEX and it uses an Apollo thermal expansion valve instead of an expansion tank. This is my first time encountering one of these valves. What is the proper way to address the expansion valve when replacing the water heater? Should I just use the existing valve, rebuild the existing valve, completely replace the valve with a new one, or replace the valve with an expansion tank? The current valve seems to be working fine. The water heater is in the garage and the expansion valve drain is plumbed to the outside using CPVC. Thanks for any advice.

 

[Master Plumber Mark]

you dont know how well it works,
I would just tear it all out and do a new stop and expansion tank