Currently I have have a standard (22mmm thread?) 230 VAC thermal actuator that turns on or off the return from the UFH manifold, as a part of the heating /cooling comtrol system.  This actuator is a NC one, that opens when 230 VAC is applied.  We have a minor problem in that when there is a call for heating or cooling there is a delay before this valve opens.  This doesn't matter in heating mode, as the ASHP can unload into the buffer tank, but in cooling mode the only load is the UFH, and becau