DIY Doctor

Main navigation

Boiler trigger is 12V, but UFH outputs 230V

Postby Haggles » Fri Jan 20, 2012 8:02 pm

We have self installed under floor heating down stairs and kept our radiators upstairs. Last month we got our electrician in to connect the systems together, so the UFH system would trigger the boiler to turn on.

Unfortunately he discovered the UFH outputs a 230V signal but the combi boiler accepts a 12V signal. He managed to coble something together by kind of bypassing the boiler time clock (I'm even less sure of what exactly he did now than I was then) but it means the heating HAS to be on downstairs to have the radiators on upstairs. This is a pain and a waste so my dad wants to get him back in to disconnect the whole thing.

Is there any way to step down the trigger from one system to the other? Would a simple AC/DC power brick (like for laptops) work?

Any thought would be welcome. Thanks.
Rank: Labourer
Progress to next rank:
Posts: 2
Joined: Fri Dec 10, 2010 5:14 pm


Simply Build It

Postby sparx » Sun Jan 22, 2012 8:46 am

Hi, a simple relay with a 230v coil will do fine the contacts are then used to switch the 12v circuit, any competant electrician should be able to fit this.
Most electrical wholesalers will stock one or if you have a Maplins store nearby:
Part # N13AW plus base JG52G @ £4.09 + £1.69 respectively .
other suppliers also such as CPC should stock similar,
Rank: Project Manager
Posts: 2166
Joined: Wed Mar 21, 2007 8:33 pm
Location: The fifth continent.

Postby Dick Puller » Sun Jan 22, 2012 9:20 am

Is this the same thread as below??

In most cases the micro switch on the zone valve is used to control the boiler, as in an 'S' plan. The low voltage/no voltage supply from the boiler is switched that way when the UFH is calling for heat.
Dick Puller
Rank: Apprentice
Progress to next rank:
Posts: 11
Joined: Sun Jan 22, 2012 8:44 am

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics