Ufh With Heatrae Sadia Electromax ?

[Richnap83]

Hi, I've just bought my second house and have started some renovations. The house had wet electric central heating via radiators. It has the heatrae sadia electromax boiler and I was wondering if I could run wet electric UFH down stairs and keep the radiators up stairs? I see there is a special electromax boiler for UFH and wondered what the difference is? Thanks in advance for any advice.

 

[ProDave]

UFH generally runs at a lower temperature. It's normally mixed down within the manifold for the UFH so can take a normal hot feed.

Perhaps the "special" bouler just runs at a lower temperature.

There's no problem mixing radiators and UFH, except UFH takes longer to warm up, so consider a separate time clock for the UFH so it can turn on and off at different times to the radiators.

As this is a renovation, I'll warn you, you MUST install a LOT of insulation under your floors, otherwise a lot of your heat will be wasted heating the ground under your house, so do check you can fit a sensible amount before proceeding.

 

[Richnap83]

Cheers ProDave, if this "special" UFH boiler runs at lower temp would it still be able to run radiators? As for the insulation I'm thinking a solid concrete subfloor with 70mm insulation on top and f/f screed on top of that?

 

[ProDave]

Is this the special UFH boiler you are thinking of?  http://www.heatraesadia.com/amptec_system_boiler/

If so then that's just a small low power electric boiler to run an UFH system and just that.

Whereas the full electromax boiler incorporates a 180 litre unvented hot water tank as well http://www.heatraesadia.com/electromax/

70mm under floor insulation is borderline. I would try for 100mm or even 150mm and something decent like Kingspan or Celotex.  Much easier on a new build to get lots of insulation I know, but it will be worth the effort in the long run.

 

[Richnap83]

It's the second boiler that I have, but there seems to be two models. The underfloor model runs from 30-60 deg and the radiator version (that I have) runs from 65-80 deg. Its on page 5 of the installation guide under tech data.