Connecting floor heating

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beemer

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This is probably a long shot , but, I am in the process of wiring up warm water underfloor heating and wondered if there are anyone able to answer a wiring question?

A new Worcester GREENSTAR Ri RSF Gas Fired Condensing Boiler has been fitted and working and the underfloor heating system has also been fitted, but the electrical side has been left to me! Armed with the instructions I have wired the electrical supply, actuators (for the 2 zones) and pump to the 'Master connecting box' or 'Intelligent UPH Wiring Centre' (as it is called, depending which literature I read).

I also have a cable to connect from 'wiring centre, to boiler so that the underfloor heating system can control power to the boiler on demand. I have connected E,N and SL on the 'centre' so really need to know to what connections I use on the boiler?

This is a long shot, I know, and I do have both electrical plans of boiler and Underfloor heating.

Thanks anyway...

Dave

 

steptoe

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your 'actuators' ,

do you mean a motorised valve?

if your boiler controls more than just the UFH then I would suspect this is what you mean and therefore your control wires would go to the motorised valves.

can you give us a little bit more info please. ?

 
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Steptoe: The actuators (yep, zone, or 2 port valves) connect to the UFH control system. I believe o/p needs the control system to fire the boiler on demand.

Beemer - If memeory serves, the Worcester uses low voltage switching for external controls. It USED to be pins 4 & 5, but if you can post or PM the boiler wiring instructions, we can confirm. I also need to know the spec. on the output signal from the UFH controller - is it throwing 230V at the boiler? If so, you`ll need a relay in line:)

 

steptoe

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my understanding KME would be the UFH sends a signal to the room stat, which in turn opens the valve when it needs heat and then the valve sends the signal to the boiler to fire cos it has opened,

bit like a Y plan I would have thought.

can I assume this is a combi?

 

beemer

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your 'actuators' , do you mean a motorised valve?

if your boiler controls more than just the UFH then I would suspect this is what you mean and therefore your control wires would go to the motorised valves.

can you give us a little bit more info please. ?
Thanks for your answer, I hope I can explain better Steptoe...

There is a manifold with it's own pump to supply two separate zones for the underfloor heating, and two 'actuators' (as they are called in the 'operating instructions' ) or motorised valves, these have been wired correctly as per the wiring diagram to the 'wiring centre' (a separate box with PCB's).

The question is with the link between the 'wiring centre' and the boiler, because the underfloor heating needs to tell the boiler to fire up to provide the hot water for the underfloor heating.

When wiring the supply for the boiler, it is connected to the ST1 terminals. Would I therefore connect the 'wiring centre', to the ST2 terminals?

Just to clarify...boiler is a condensing boiler not a combi.

 
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Steptoe:

DON`T ASS.U.ME anything!!!!!!!

I don`t know mate - if it`s a muti-zone system, they sometimes have a central timing/control/firing system.

We`ll have to wait for more input from o/p mate.....

As if by magic:

Beemer: sp1? sp2? needs more input. as above post. If the wiring centre throws 230 at combi, and it wants low voltage external control, you`ll squiff the boiler. Worcester charge oooodles for a new PCB.

 

steptoe

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as I understand beemer,

its actually the valves that tell the boiler to fire, via the wiring centre,

but,

as has been noted, you MUST ensure if you boiler uses a 230v signal, or a much smaller 20v(or suchlike) signal,

this will be in the boiler instructions somewhere.

 

steptoe

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Thanks for your answer, I hope I can explain better Steptoe... There is a manifold with it's own pump to supply two separate zones for the underfloor heating, and two 'actuators' (as they are called in the 'operating instructions' ) or motorised valves, these have been wired correctly as per the wiring diagram to the 'wiring centre' (a separate box with PCB's).

The question is with the link between the 'wiring centre' and the boiler, because the underfloor heating needs to tell the boiler to fire up to provide the hot water for the underfloor heating.

When wiring the supply for the boiler, it is connected to the ST1 terminals. Would I therefore connect the 'wiring centre', to the ST2 terminals?

Just to clarify...boiler is a condensing boiler not a combi.
dont make it NOT a combi,

mine is.

so there must be a hot water tank then if its not a combi?

if there is a timeclock for the UFH you may be able to simply use a no volt set of terminals in that and ignore the sw line from the valves.

 

beemer

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Steptoe: The actuators (yep, zone, or 2 port valves) connect to the UFH control system. I believe o/p needs the control system to fire the boiler on demand.Beemer - If memeory serves, the Worcester uses low voltage switching for external controls. It USED to be pins 4 & 5, but if you can post or PM the boiler wiring instructions, we can confirm. I also need to know the spec. on the output signal from the UFH controller - is it throwing 230V at the boiler? If so, you`ll need a relay in line:)
Thanks also kme, I am in the process of collating data ready to send to you.

 

beemer

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Thanks, trying to keep up with your replies guys :D

ST1 and ST2 are the terminals on the boiler pcb. ST1 is always the main incoming supply to the boiler (on Worcesters).

Take your point on blowing up boiler pcb, so would like to get this one right.Pray

 
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I know this is of no help at this stage but with these systems I don't like it when the heating guys just say thats our bit done , leave it with you Sparks. Well sorry but its their system , I want a comprehensive wiring diagram to work to, not make it up as I go. Worst case senario, I cock up the wiring , pump overrun does not operate , boiler buggered, bill for

 

avinalarf

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Sorry to butt in gents. I've read this thread with interest, even though most of it is double-dutch to me! I've recently had UFH installed, with 2 zones and added to my current condensing boiler (Vaillant) and my concern was how the GCH engineer had wired it up...

For testing purposes, as there was no FCU in place yet, he put a 3-pin plug on the end of the circuit supplying the UFH and anyone who touched the plug got quite a nice jolt!

My assumption (I know we shouldn't make these!) is that this is incorrect. He said that this was caused because there's no way of isolating the supply for the UFH as it was going (techinical term!) via the boiler, which is always on.

I have since wired the supply cables for each zone into 3A DP switches, but wondered if anyone could alleviate my concerns.

Hope the above makes sense 'cos I think I've confused myself!!!

 

sparkyrj

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In the past i have wired a few of these systems, with the actuators that are on the manifold controlling the various zones,and the pump being connected to the wiring centre, and their is usually a motorised valve for the underfloor system only . The microswitch in this then goes to the boilers switched live terminal with any others from hthe hot water cylinder and radiators. The motor supply on the valve is taken from the wiring centre.

 
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I've recently had UFH installed, with 2 zones and added to my current condensing boiler (Vaillant) and my concern was how the GCH engineer had wired it up...For testing purposes, as there was no FCU in place yet, he put a 3-pin plug on the end of the circuit supplying the UFH and anyone who touched the plug got quite a nice jolt:|!
It's always wrong if you are getting shocks off it! ]:)

 

beemer

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I know this is of no help at this stage but with these systems I don't like it when the heating guys just say thats our bit done , leave it with you Sparks. Well sorry but its their system , I want a comprehensive wiring diagram to work to, not make it up as I go. Worst case senario, I cock up the wiring , pump overrun does not operate , boiler buggered, bill for
 
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