Yes, the unit shows the ASHP and zones come on when thermostat temps are raised - I’ve checked them all. Lights come on the unit, the valve on the appropriate zone lifts 2-3mm and the red in the tube indicator drops. (Only exception is the spare bedroom where all indicators work except the red in the tube which only partially moves.)

Posted by: @emmajg

↑

Yes, the unit shows the ASHP and zones come on when thermostat temps are raised - I’ve checked them all. Lights come on the unit, the valve on the appropriate zone lifts 2-3mm and the red in the tube indicator drops. (Only exception is the spare bedroom where all indicators work except the red in the tube which only partially moves.)

That's fine, the red indicator shows the water flow rate, which should have been balanced the the heat demand of each particular room.

With reference to your original post. Probably the most efficient way to operate your heat pump would be to have all the heatmiser thermostats set to 1C above the desired level, with the Vaillant controller using the WC curve to adjust the Leaving Water Temperature (LWT), to help maintain the desired Indoor Air Temperature (IAT) under varying Outside Air Temperatures (OAT). The flow rate through the UFH loops should then be adjusted to achieve the desired room temperatures.

If a particular room gets too warm then the relevant solenoid valve should close to bring the temperature back down.

When all the thermostats are set low, does the heat pump stop, though the water pump may run on for several minutes.

Helpful video! It’ set at 0.45

Posted by: @emmajg

↑

Helpful video! It’ set at 0.45

Okay, if your home is getting too warm then you could try selecting a lower curve.

If you make an adjustment remember that the system will take quite some time to stabilse, so don't expect an immediate drop in temperature, unless you open all the doors and windows. 😋 

@derek-m This has been enormously helpful. I have one last question. How does the desired temp set on the vaillant controller relate to those I set in the individual room thermostats? (Which one wins?)

Please forgive me jumping in.  We have a Vaillant ASHP and have the  same room controllers as you, ours are wired though.    Who wins depends on the settings.  We tried both ways and have now got it set so the Vaillant controller is the only heat reference.  The neostat V2 no longer control the rooms. The valves are disconnected, and the stats just indicate the temp in each room.  This has done wonders for our COP.  

Drew

@drew-pa Thanks - maybe one for us to try next.

Thanks all for your help today - you’ve been fabulous. What a great community!

Posted by: @emmajg

↑

@derek-m This has been enormously helpful. I have one last question. How does the desired temp set on the vaillant controller relate to those I set in the individual room thermostats? (Which one wins?)

The Vaillant controller actually controls the heat pump, the heatmiser thermostats just open the solenoid valves and start and stop the heat pump, assuming it has been connected correctly.

Posted by: @drew-pa

↑

Please forgive me jumping in.  We have a Vaillant ASHP and have the  same room controllers as you, ours are wired though.    Who wins depends on the settings.  We tried both ways and have now got it set so the Vaillant controller is the only heat reference.  The neostat V2 no longer control the rooms. The valves are disconnected, and the stats just indicate the temp in each room.  This has done wonders for our COP.  

Drew

By all means jump in Drew, particularly since you have a similar system and possibly the same problems.