Understanding wiring for wet underfloor heating?

[HappyHippyDad]

I have not had to do the wiring for a wet underfloor heating system before. I think I started a thread fairly recently and had some very good replies which has helped me understand heating systems in greater detail. However, I have a more specific question to this particular manifold wiring diagram (see picture).

I understand most of it, but I am unsure how to locate the 'boiler enable' terminals located on the bottom left of the wiring diagram. I'm guessing these must be located in the boiler? (its a combi, no pictures, sorry!) Are they in the boiler, and if so how do I identify them?

Second question... Where it says 'heat enable' in part of the manifold wiring centre, it says LS and LR are volt free. The cable from 'heat enable' to 'boiler enable' is therefore volt free. I initially thought this meant ELV and was just poorly worded. However, I now think it means it can take any voltage from 0 up to 230V, is that correct?

lastly, they supply 2 wiring diagrams. I have attached them both. How do I determine which one to use?

 

[HappyHippyDad]

Yes, as I said above a motorised valve is required on the flow pipe to the radiators which there appears to be already installed in the picture.

If I have understood the photo correctly the pipes with the blue and red lever valves will be the flow and return to the UFH and the, electrically unconnected, motorised valve above the red valve will be in the flow to the radiators.

Got it!
Your explanations have really helped me understand it more, thankyou.

 

[HappyHippyDad]

Yes, as I said above a motorised valve is required on the flow pipe to the radiators which there appears to be already installed in the picture.

If I have understood the photo correctly the pipes with the blue and red lever valves will be the flow and return to the UFH and the, electrically unconnected, motorised valve above the red valve will be in the flow to the radiators.

I think this wiring diagram would work.
I hope you don't mind me popping it up, so I can double check with you (or indeed anyone else).

 

[diditrain]

That should work. If your heatmiser is calling but your radiator stat is turned down, the rad zone valve should be closed. No heat to radiators.
if your rad stat is calling but your heatmisers are not calling, then your heatmiser actuators should be closed. Seems to make sense.

 

[davesparks]

I think this wiring diagram would work.
I hope you don't mind me popping it up, so I can double check with you (or indeed anyone else).

View attachment 112291

The theory is right but the colours don't quite make sense.
Most 2 port motorised valves use brown and blue for the valve motor and grey and orange for the microswitch.
So in your diagram the grey of the valve would connect to your terminals 1/2, blue as shown to 3/4, brown to 7 and orange to 9.

The heatmiser box you have has the facility to connect the room stat and motorised valve for the existing heating zone, this is another option if it is going to be local to the boiler

 

[HappyHippyDad]

The theory is right but the colours don't quite make sense.
Most 2 port motorised valves use brown and blue for the valve motor and grey and orange for the microswitch.
So in your diagram the grey of the valve would connect to your terminals 1/2, blue as shown to 3/4, brown to 7 and orange to 9.

The heatmiser box you have has the facility to connect the room stat and motorised valve for the existing heating zone, this is another option if it is going to be local to the boiler

That's brilliant Dave, thanks again.
I had to raid my sons felt tips and pencils for any colours available!
Apologies for the strange and incorrect colour use.