Adding UFH pump to existing “S” plan system

[slim reaper]

Hi, folks, great forum bye the way . Ive been doing Diy plumbing since the early 1970’s on rad systems. I have now installed wet ufh in the cir 1800’s part of our present property and am stuck with how to control it. I have an “S” system, older L,N,E wired heat only oil boiler with no pump over run or room stat by choice, I would like to add the wiring for the zone valve, pump and programmable room stat to operate a newly installed UFH circuit and to have it run independently or together with the existing heating .I would be grateful if someone could please tell me if its possible to run the second pump this way and if so ,how to wire it.
Thanks
slim

 

[EvilDrPorkChop]

Wire your UFH Live pump wire to the Brown wire on the motorised valve that controls the UFH circuit.

 

[slim reaper]

Wire your UFH Live pump wire to the Brown wire on the motorised valve that controls the UFH circuit.

Thank you very much, I’ll give it a whirl

 

[slim reaper]

Thank you very much, I’ll give it a whirl

Ive had a look at

Wire your UFH Live pump wire to the Brown wire on the motorised valve that controls the UFH circuit.

Ive had a look at this and am wondering how this would work with my system is.
Because the boiler and existing pump are powered from the same live terminal, the ufh control wiring would need to fire the boiler on the same one and in doing so would turn the existing pump on as well?

 

[EvilDrPorkChop]

Ive had a look at

Ive had a look at this and am wondering how this would work with my system is.
Because the boiler and existing pump are powered from the same live terminal, the ufh control wiring would need to fire the boiler on the same one and in doing so would turn the existing pump on as well?

The Orange wire from the Motorised valves is the one that fires the boiler and brings your boiler pump in.

The Brown to the motorised valve only powers up the motor to open the valve to close the mircoswitch. In wiring your UFH pump to the brown wire will only bring the UFH when the motorised valve for the UFH opens I.E when your UFH programmable stat clicks in.

 

[ShaunCorbs]

The Grey wire from the Motorised valves is the one that fires the boiler and brings your boiler pump in.

The Brown to the motorised valve only powers up the motor to open the valve to close the mircoswitch. In wiring your UFH pump to the brown wire will only bring the UFH when the motorised valve for the UFH opens I.E when your UFH programmable stat clicks in.

Don’t you mean orange ?

 

[EvilDrPorkChop]

Don’t you mean orange ?

Yeah, sorry. Sunday afternoon 🙄

 

[slim reaper]

The Orange wire from the Motorised valves is the one that fires the boiler and brings your boiler pump in.

The Brown to the motorised valve only powers up the motor to open the valve to close the mircoswitch. In wiring your UFH pump to the brown wire will only bring the UFH when the motorised valve for the UFH opens I.E when your UFH programmable stat clicks in.

The Orange wire from the Motorised valves is the one that fires the boiler and brings your boiler pump in.

The Brown to the motorised valve only powers up the motor to open the valve to close the mircoswitch. In wiring your UFH pump to the brown wire will only bring the UFH when the motorised valve for the UFH opens I.E when your UFH programmable stat clicks in.

Thanks, I’m not sure where all the wires would go from the new zone valve that will turn the boiler on without the old pump seeing they are both powered from the same terminal?

 

[EvilDrPorkChop]

Thanks, I’m not sure where all the wires would go from the new zone valve that will turn the boiler on without the old pump seeing they are both powered from the same terminal?

I think if you're struggling with this then you probably need a heating engineer or electrician in.

The microswitch is what fires the boiler, this is independent of the Motorised Valve motor (Brown wire). In doing so the UFH pump when connected to the brown wire would only run when the UFH requires a demand, when there's a demand elsewhere on the system it would not run as the microswitch is what separates it.

 

[slim reaper]

Thanks,I will have another go when I get a room stat, would this one be ok?

 

[EvilDrPorkChop]

Thanks,I will have another go when I get a room stat, would this one be ok?

Yes although wouldn't have been my choice.

 

[slim reaper]

Yes although wouldn't have been my choice.

As a matter of interest, what would that be?

 

[EvilDrPorkChop]

As a matter of interest, what would that be?

One of these - CP4B - OpenTherm® Battery Operated Programmable Thermostat - EPH Controls - https://www.ephcontrols.co.uk/section/cp4b/

Dead easy to use. Can't really go wrong with them.

 

[slim reaper]

I had an offer in on 3bay for the one I mentioned and by the time I’d read your preference it had been accepted so had to go ahead and pay for it but thanks anyway.