UFH 4 Wire Actuator Wiring

MattyH · Mar 22, 2020

Hi, just recently wired in my single zone (4 loops) wet UFH system. I found it relatively simple as I think it is a basic layout. Heating is S plan (UFH/Rads) however it is only wired together using (the supplied) box with a big choc block connector rather than these fancy wiring centres you see. General flow is stat powers up the 2 port valve, which then send a signal to both the boiler and pump et voila. However the pack included an actuator valve which sits where the flow enters the manifold and AFAIK acts as a kind of TRV, but i can't seem to figure out how to wire it. It has 4 wires, so I can only assume Live, Neutral and the other two maybe a switch similar to how the 2 port valve works, but trial and error hasn't really worked.

Anyone any ideas please? Wiring diagrams seem to be impossible to find for the 4 wired versions

Wilko · Mar 22, 2020

Hi - can you advise the make and model of the controller please? Any pics?

MattyH · Mar 23, 2020

Hi, not sure of the make/model, just looks "generic" but have attached some pics. I rightly/wrongly assume that the brown/blue wires are live/neutral and the black and grey are a switch same as the grey/orange of the 2 port valve. Thought I'd reach out to anyone who has a hit more of a clue. My other assumption is that if I can figure out the wiring, this should open at the same time the pump switches and boiler fires up.

Wilko · Mar 23, 2020

Hi - I think this actuator controls the mixed hot water flow to the individual UFH zones. They are typically either 24V or 240V, so they need to be the correct type for your controller. Hopefully they’ve got that right for you. The 2nd pair of cables is for a pair of contacts, which again could be normally closed or normally open depending on the system design. Sorry I’d only be guessing which conductors do which function, but this could likely be established by testing if the manufacturer’s instructions are no use.

MattyH · Mar 24, 2020

Thanks for the help. I managed to get the actuator to move by trial and error but not when I wanted it to. Researching around I don't think it is actually required since we only have a single zone, so all 4 loops will either be on or off. Just gonna remove it

Thanks