combination boiler & underfloor heating

[evgeny]

Hi,

We would like to install underfloor heating in our flat. It is more convinient for us to use combi boiler rather than system boiler (boiler +cylinder)

One of the installer told us he does not recommend to use combi boiler with underfloor heating in our flat.

He failed to explain properly, but now we are not sure we can safely use combi boiler for underfloor heating.

Our flat is 85 square meters. We have bathroom and en-suite. We will have only underfloor heating in the flat + 2 tower rail (one in bathroom and one in en-suite). We also want to install one radiator in the utility room below the flat.

Any idea why combi boiler will be bad for heating in this flat. (I understand minuses for DHW) One installer claim he needs to modify combi boiler to be used for heating in the flat. Any ideas why will greatly help.

Thanks!

 

[davetheplumber]

No probs whatsoever in doing what you want providing you use the correct manifolds. Dont forget to have a word with your sparks if you want independent zones.

 

[evgeny]

Thanks, what do you mean by correct manifolds ? We plan to use manifold that has built in UHF pump. Is it correct ? The installer that did not want to connect combi boiler to UHF told us about combi pump and the need to modify pump in combi, but we failed to understand what needs to be modified.
Thanks for answering !

 

[stevetheplumber]

never heard of modifying the pump in a combi for underfloor you could keep the towel rails on a seperate cicuit to the rads and ufh and have towel rails hot in summer

 

[JPlumbUK]

I have fitted many combis with UFH.use seperate pump n manifold, as long as the sparky knows his job theres no prolem.

 

[Cds]

There used to be some problems with UFH mixing valves and combi boilers (10 years ago) to do with the design of the valve and the boiler pump being on the return. This type of problem has been resolved and there should be no reason why UFH can not be used with a combi.