HCC100 and 2 port valve wiring

[Mfourc]

Hi,
I’ve just had underfloor heating installed downstairs at my home. Upstairs has an EvoHome system with all radiators having the evohome TRV’s. Prior to the installation of the UFH I had a two zone system (one zone being upstairs, further zoned within evohome, the other being downstairs). Each zone had a separate 2 port valve controlling it. With the addition of the HCC100 for the UFH, and retirement of the old controller that ran downstairs, how do I wire in the 2 port valve to provide isolation of the IFH when no room downstairs calls for heat?

[Richard]

The HCC100 has a 'Pump' terminal which gives a switched live but only operates when there is a demand for an UFH zone.

You wire it similar to how the HCC80R used to be wired (I will do a HCC100 version when I get 5 minutes)...

hcc80r-wiring-diagram-for-motorised-zone-valve copy.jpg (219.09 KiB) Viewed 396 times

[Mfourc]

Ah, ok so i effectively wiring the positive from the ‘pump’ connection to trigger the 2 port calve and then have the Grey / orange wire from the valve to be permanent 240v and switched wire to the pump respectively?

[Richard]

Yes correct, although the above diagram shows the grey and orange made safe.