Underfloor heating and vented/sealed CH system

[confused1978]

Hi folks,

This is my first post here, so please be gentle! I hope someone might be able to help with my question.

I am about to build an extension to my home - it is around 45 sq metres, and would like to run UFH in the new build areas. The plumber has suggested we change our current vented central heating system to a sealed one to work better with the underfloor heating. Apparently our old vented system will not allow the heat to be distributed correctly, or something like that. I didn't fully buy his explanation.

I don't want the expense of going to a pressurised sealed system (not to mention the risk of leaks from the old plumbing joints!) if I don't have to. Does anyone know, if a sealed system is needed alongside underfloor heating?

Regards,
Kevin.

 

[bellairaphon]

Ideally yes. But it can work open vented. Get your plumber to seal the ufh side and run it through an external plate heatex.

Nath

 

[dcawkwell]

Sealed system is better. vented systems belong to the dark ages and have
no place in a modern heating system.
Conversion kit costs about £80 plus fitting which shouldn't take more than about 1 hr.

 

[confused1978]

Thanks for the information. I'll investigate the vented option.

That said, why exactly is it better to use a sealed system? I have plenty of space in the loft, so losing the tank there doesn't really help me.

Regards,
Kevin.

 

[dcawkwell]

Thanks for the information. I'll investigate the vented option.

That said, why exactly is it better to use a sealed system? I have plenty of space in the loft, so losing the tank there doesn't really help me.

Regards,
Kevin.

No air gets into the system. You know when you have a leak straight away instead of when all your radiators have rusted through.
If you have a major burst the header tank will happily keep pumping water into the house and wreck the house. I've see that. A burst pipe while the lady was away over christmas when she came back the place had to be gutted she was out of the house for 6 months while the insurance rebuilt the house.
No problems with air locks and the like when refilling.
Easy to flush the system through to remove dirt.

 

[SimonH2]

The plumber has suggested we change our current vented central heating system to a sealed one to work better with the underfloor heating.

Others have given reasons why that may be a good idea.

Apparently our old vented system will not allow the heat to be distributed correctly, or something like that. I didn't fully buy his explanation.

But that's complete "rubbish". If he can't make it work as an open vent system then you should "question his competence".