How to fit smart thermostats to underfloor heating

[Paul G1]

Hi I have underfloor heating - it’s brilliant.
I’m trying to change thermostats to Smart Thermostats.
Ok with wiring apart from the brown and black wire from my combi boiler.
Black is from LS
Brown is from LR
The new control box has a N & L and a COM & NO block
I’ve attached a couple of pics .
Anyone advise where these 2 wires go please?

 

[CBW]

LS to Com
LR to NO

I presume you know to give it L and N?

 

[Paul G1]

Thank you that’s brilliant . When you save L and N - is that separate to the mains live already connected to the left on the pic ?

 

[CBW]

Thank you that’s brilliant . When you save L and N - is that separate to the mains live already connected to the left on the pic ?

I can’t even see anything connected to the L and N on the left, but nothing separate, just take a live and neutral (from the same source) to the one on the left, often piggybacked.

 

[Paul G1]

Sorry my mistake - I’m only a DIY’er so bear with me.
I meant the mains st No:5 on diagram
Just to be sure.
LS to Com
LR to No
When you say take a live and neutral from same source and piggy back onto the L&N at No:7 - where from exactly?

 

[CBW]

What exactly do you have currently for controlling your under floor heating (ufh)?

 

[Paul G1]

This is the current set up with wireless thermostats but the time set up on them is poor so going for smart controls .
Do I just piggy back off the mains live and neutral terminal ?

 

[CBW]

Ahh, right, so the mains would be the mains, and copy all others over.

 

[Paul G1]

Getting back to your previous comment -
‘I presume you know to give it L and N?’
Does it need a L & N at blocks 7 on new box as there is already a mains connection at 5 ?
Or do i piggy back off that with a L&N?
Sorry to be a pain

 

[CBW]

Getting back to your previous comment -
‘I presume you know to give it L and N?’
Does it need a L & N at blocks 7 on new box as there is already a mains connection at 5 ?
Or do i piggy back off that with a L&N?
Sorry to be a pain

No apologies, it was me who muddied the water.
Mains input to number 5
Pump wires to number 6
LS to com
LR to NO

 

[Paul G1]

That’s really good of you to take the time to respond . I’ll sort it all tomorrow and drop you a lane . Thanks again you’ve been a great help !

 

[Paul G1]

Hi. I’ve connected it as you suggest and all lights up and smart controls connected but when I attempt to turn it on it doesn’t fire up the boiler - everything else kicks in but boiler just doesn’t fire up ?

 

[CBW]

Definitely have Ls and Lr?

 

[Paul G1]

Yes - Worcester boiler
Pressing the test button
the pump starts up
Relay ignites boiler
It lights up the actuators but doesn’t fire up boiler?
Stumped !

 

[CBW]

Yes - Worcester boiler
Pressing the test button
the pump starts up
Relay ignites boiler
It lights up the actuators but doesn’t fire up boiler?
Stumped !

What do you mean, relay ignites boiler? But then doesn’t fire up?