Installing Hive Multizone to Vaillant ecTEC 937

[Tim Green]

Sorry to bring this topic up again but I thought I had it sorted but the heating is only working upstairs (zone 1)
I originally had a VRC 470f stat and VR 61 mixer module but the 470f has finally given up after 4 years of suffering - and my god have we suffered!

I removed the VRC 470f panel from the boiler front and replaced with the blank panel.
I removed the 24V RT bridge on PCB
I removed the eBUS connection (2 wires) on PCB and replaced with a single wire from RT 230V to 9 on the wiring centre
I reinstated the orange and brown wires on the the 2 port valves (they had been taped up for use with the VRC 470f)
Then completed the wiring as per the diagram below.

Any help would be gratefully received. Hive appears to be working on both zones but only zone 1 actually heats up.

 

[stem]

Assuming both Hive thermostats are the single channel version, then from a wiring point that all looks as it should to me.

I would start by checking the Zone 2 Motorised valve. Is it physically opening when the Zone 2 Hive switches the heating on? If not, is there 230V present between its live and neutral?

 

[Tim Green]

You were right. The valve was ok in that it was working fine for the Vaillant controllers whick worked using L/N/E only. I reinstated the grey/orange switch wires for Hive but there was obviously a fault there. Installed a new actuator on the valve and all is good. Many thanks for your direction.

 

[stem]

Looks like the fault was with the motorised valve's internal switch. When the valve opens it switches 'on' and the grey and orange wires are connected together to provide a live supply to the boiler.

In your case it would appear that the valve was opening OK [hence why you hadn't noticed it before] but the switch wasn't working in order to start the boiler via the newly reinstated orange & grey wires.