Linking two zones - removing one thermostat

[pjblink]

Hi all,

I have a 2-zoned ASHP system, one thermostat upstairs and one downstairs. I'd like to test running the system as one zone from one programmable thermostat - how can I do this easily and temporarily?

Both thermostats have L/N going to common terminals on the HP and a Brown/Grey going to two separate sets of terminals.

 

[CBW]

If the motorised valve head is detachable then detach this, move the spindle to open and then run from one programmer

 

[pjblink]

There's a 3-port valve covering Heating/DHW but no further valve for the two zones - just two pumps.

 

[CBW]

Sorry, I wouldn't know with ashp, thought there were zone valves