2nd Zone UFH and 2nd pump

[25146447]

Hi,

I require a second pump connected to a 2nd zone.

System is S plan, just a bit stumped with how you only get the pumps on that are calling for heat with only one boiler.

Zone 1 at moment pump and boiler comes off 10 which is right but the 2nd pump has to go in 10 as the neutral and earth are common I can't see how you stop the both pumps firing up when only 1 zone calls for heat.

Only way I can see is a relay or contactor but I can't remember the basics with them been that long since used one.

Anyone got any diagrams that can help??

Thanks Rich

 

[Wilko]

Hi - this thread’s got some info on the subject from @Leesparkykent which helped me .

Underfloor heating help - in - UK Electrical Forum

, Underfloor heating help, UK Electrical Forum, ElectriciansForums.net Est.2006 | Free Electrical Advice Forum and page_number.

www.electriciansforums.net

 

[cliffed]

The valve will operate the 2nd pump for 2nd zone

 

[25146447]

The valve will operate the 2nd pump for 2nd zone

Yes true, but if one boiler link 10 it will activate the other pump and vice versa.

 

[cliffed]

2nd valve used to control pump,room stat will Ctrl this,switch valve,which will operate that pump.
see what you mean with the signal to the boiler & pump.
The orange from the valve could feed the pump,but would not on that zone fire the boiler

 

[25146447]

2nd valve used to control pump,room stat will Ctrl this,switch valve,which will operate that pump.
see what you mean with the signal to the boiler & pump.
The orange from the valve could feed the pump,but would not on that zone fire the boiler

Yeah bit of a head scratcher, never know the Ufh pumps might have their own wiring boxes that have the next relays.

 

[Midwest]

If I recall the last one I did, its was S-Plan+, with the UFH having its own 2 port valve, and the UFH manifold & pump with live feed, and switch live from room stat to the 2 port.

The UFH manifold will then blend the water in the UFH loops, with the heated water from the boiler, to the required temerature. Otherwise the floor would be too hot to walk on.

 

[davesparks]

For multiple pumps you will effectively need a relay for each pump fitted.
You must always have a pump connected to the boilers pump overrun terminal, so if there isn't a seperate circulating pump for this purpose you will need the relays to always leave one pump connected even when all zones are off.

 

[Midwest]

Not for the UFH pump, sorts itself out.

 

[StephenRowley]

View: https://youtu.be/VRqinTBkGSA

 

[davesparks]

Not for the UFH pump, sorts itself out.

Assuming there is also a circulating pump for the boiler overrun yes.

 

[Midwest]

Think we might be at cross purposes. The UFH pump, has nothing to do (socially as it were) with the CH system. It just lives in a world of its own circulating water around the UFH loops.

 

[25146447]

View: https://youtu.be/VRqinTBkGSA

Sorted 2 contactors it is then.

Cheers

 

[davesparks]

Think we might be at cross purposes. The UFH pump, has nothing to do (socially as it were) with the CH system. It just lives in a world of its own circulating water around the UFH loops.

I take it you've actually seen the system the OP is working with then?

Not all systems work like that.

 

[Midwest]

I take it you've actually seen the system the OP is working with then?

Not all systems work like that.

Ok stand corrected then.

However, all the UFH systems I've worked on, come as kit to add to existing CH systems. Unless your talking of a bespoke UFH system, for large premises. Bit like the place I work in now, which has a large circulating flow & return, and the manifold takes its blend from that.

 

[davesparks]

Ok stand corrected then.

However, all the UFH systems I've worked on, come as kit to add to existing CH systems. Unless your talking of a bespoke UFH system, for large premises. Bit like the place I work in now, which has a large circulating flow & return, and the manifold takes its blend from that.

Most domestic ones I've done these days do seem to be the kit type. Thinking about it it is a few years since I've seen it done directly from the circulating pump just like any radiator zone.