expansion valve problem

[housed]

We have a situation with a water to water heat pump.

If the bulb of the expansion valve is stick to the pipe , after 30 sec is closing the flow and the pressure goes up (at 20 C is reaching 2.5 mpa)

If we remove it from the pipe, and is not regulating the flow, the heat pumps works perfect.

It is a thermal expansion valve from Emerson ....

[marvin]

are you sure everything is positioned properly & your charge is
correct

[mseng]

Is it a water furnace? They had a bad batch of TXV's that when out. It sounds like the TXV has lost some of its head charge.