UFH Warm water conversion

[Gora]

I'm thinking of converting my existing CH system to UFH with warm water. The house is a 1930's semi, with 4 rads upstairs, and 3 downstairs, with heating from a wall hung Potterton Netaheat boiler.

With the exception of the kitchen, floors are boards on joists, and predominately carpeted (although it is my intension to go to a wood/laminate surface at some point in the future).

Are there conversion kits from rads to UFH on a per room basis? -and are they any good?

Should I consider a second boiler just for UFH and retain the existing for just hot water usage?

What component suppliers would be recommended for a competent DIY'er, where cost is an issue, but installation hard graft and competence isn't?.

I know I could trawl the net endlessly for answers, but am hoping that posting here might sort the wheat from the chaff.

Cheers (and HNY!)

[IMM]

No.

Polyplumb do a an insulation floor panel strip that can be laid over an existing floor.

The floor level is raised an inch or so, then laminates cam be put over.

I would install insulation between the joists on the downstairs floors. This is essential. A condensing boiler is essential as its efficiency is raised on low temperatures. Look at

for a heat bank.

Why do you want underfloor heating? You could insulate under your wooden downstairs floors, install triple glazing, install letterboxless highly insulated doors, make the ceiling air tight to the loft, seal up chimney breast as flues just draw out hot air and install 1 foot of insulation in the loft. Then you will not require too much heating at all. Do the calcs and some skirting heaters may just do the job.

The insulation will keep the house cool in summer too.

[Rick Hughes]

I have installed a full UFH system, if you want to bounce any questions about that.

The key thing is that you will need a way to keep water temp low, new systems have a thermal store (as mine has) ... you could arrange a temp blending valve, 3 port 28mm valve.

Then use the output to feed the main UFH distribution manifolds. Go for a fully pressurised sealed system.

All my parts came from NuHeat, a friend has just installed a system using PolyPipe which is not too dissimilar.

Rick

[The Natural Philosopher]

Sort of. However its harder to do that way.

No, but you do need some mods.

Fisrt of all your CH water will be hotter than is safe for UFH. So you need probably a temp reduction valve and secobndary circuit. This is why its not possible to simply replace radiators with loops of underfloor pipe.

Secondly the balancing and zoning is somewhat different on UFH. Its easier to do this centrally.

have very good literature, though some of teh pats are not the cheapest or best.

If at all possible, I would sya that a complete rip up of the ground floor boards, followed by laying of solid floors over insulation with embedded water pipes is the optimal way: At first floor level its even harder.

The result, given a decent amount of wall insulation, is totally superb tho.

[Yekal]

[Andy Hall]

These are really orthogonal issues.

The issue of whether or not you want a combi boiler has to do with the amount of hot water production that you need.

Have a look in Google Groups at previous threads on the subject. Generally for single bathrooms, as long as the water supply is adequate then a combi *may* produce enough hot water. If it's a larger property with two bathrooms or simultaneous bath and shower use then do the sums very carefully.

For UFH you need the heating water at a lower then normal temperature. To achieve this, either a blending valve is used or a boiler (typically modulating condensing type able to deliver the lower temperatures required directly.

.andy

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[IMM]

Two bathroom models are available.

That's better.

[Andy Hall]

One needs to look very carefully at the spec. "Two bathroom" is a rather imprecise term.

.andy

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[Andrew]

I thought the Polyplumb solution was a bit deficient technically. OSMA seem to have a new and very enlightening PDF on their website. Plenty of nice diagrams too.

[Rick Hughes]

Rick