underfloor heating tips??

Hi
I have a combi with two zone valves, one to supply the u/f and one to supply the rest of the house,

Works fine.

Also, I might add, on another system, I installed three zones with a combi, one on the heating circuit downstairs heat upstairs heat and unvented cylinder,

The system was bespoke for a customers needs, large house, but often only one at home,
So combi for ensuite shower, and kitchen, and unvented for bathrooms,

So just design it how you like!

Regards
Peter

 

No tips as such, Rusty - but to go for it

Perfect for modern condensing boilers as return water is nicely cool = more efficient.

Also, it has to be the nicest way to heat a room - a gentle all-over warmth, no cold spots, and obviously comfy even on t'floor - for when you slump there after a good night oot. Or in.

No 'orrible rads either, as you said.

Def go for it.

 

Great advice.

A lot of combi's can have conncted to weather compensators, so will optimise the boiler according to outside weather.

 

Have a look at Nu-Heat too ... I used their design and supply service for mine.

Consider how your new floors will be constructed and design around the UFH.

For example: on the ground floor we had North-South joists with Celotex and hemp insulation, then laid 18mm ply East-West with 16mm gaps to fit the heat spreader plates and pipes into. The finished floorboards will then run North-South.

 

We have u/f heating put into an extension for my mum who lives with us now. It's lovely but there is a slow response to external influence. For example the temp seats back a degree at night and then returns to normal a 5am. Will take approx 2 hours for the floor to warm up. Then if it's a sunny day, her room window faces south, the sun pours in and the residual heat in the slab over heats the room. I have set the stat to set back a degree at 10am which is before the sun really hits the room and that helps but if there's no sun and it's cold have to remember to manually turn it up. In my opinion it's good if you are at home a lot, but if your lifestyle is out at work all day but have the heating come on say a hour in the morning then when you get home at night then you may find rads better. Ufh likes to be on all the time albeit with night setback.

 

A lot to be said for using smart apps like Valliant vSmart to control your boiler & the heating, & used in conjunction with a weather compensator.

 

We discussed weather compensation but my installer reckons there are still issues. In my example it would have made no difference because as I understand it the weather compensation stat should sit in a sun free place, ideally north facing and being as the ambient temp was chilly but the sun gain considerable it would have still overheated the room.

Don't get me wrong, on the whole very happy with it, made best use of the space, no rads, nice and comfortable, BUT get used to being too warm unless you set it on the low side. Very difficult to get right. Its a cheaper nicer form of heating than old storage heaters, but with similar issues. IMHO anyway.

 

Hi
If it's installed fine, if not, there are options.

Not only can you zone the floor areas, you can sort of lace the u/f pipe work, to give you a high and low setting?

Bit like two forks interlaced, if that makes sense?

Regards
Peter

 

Now that's a good idea

Seen it done with two zones in one room like below, controlled by a 2 zone programmer,each set to a seperate temperature, but interlacing would be a better option, better heat spread.

 

Hi
my idea is copyright!

Regards
Peter

 

I'm a recommended UF installer with Polypipe

Polypipe will design if requested a free insured design, it can take up to 4 weeks though.

If you phone a rep, they are normally are happy to attend a site visit.

For large projects with high end clients you MUST produce accurate drawings on CAD to them for liability purposes.

But guessing with a combi it's a small area.

You will need remove any internal boiler clocks, fit a single channel programmer and Room stat for each room going back to the manifold for the UF, programmable room stat for rad circuit, each system requiring its own zone valve, be aware hot water priority with this system! Also boiler KW is enough & don't go by its name that's the max hot water KW. Controls need to be run through a wiring centre of coarse, remember pp will always push sales! UF fitted correctly is great, boiler best located away from bedroom for comfort temp adjustments in cold weeks as boiler will fire early doors, you need to also use the Htg F & R as primary's so tee the manifold & Htg return together as a comman return correctly, any zones with numerous loops get linked on the manifold to one stat

 

Think my system was designed by pollypipe, can't be sure though. def had drawings, measurements, flows rates etc specified. All installed professionally. No mention of a twin circuit but the stat is a Honeywell cm907 which is tpi and reduces the on time as the set temp is approached.

Room still overheats if its get sunny though and no way to avoid it imho cos by then the floor slab has so much stored heat.

 

Thought it wasn't fitted yet?

 

Wrong person.

 

Good to have Fred's input on this as an actual user - I can imagine that it's a slowly-responding system compared to conventional rads; the UFH has presumably warmed up the whole floor covering (laminate, hardwood, etc) so this will behave like a heat sink.

I'd still go for it tho'

 

its good, done get me wrong, but there are some con's.

 

UF fitted correctly is a luxury, very low running costs & low KW input for output.
if it was **** no one would use it, Ive done some big houses for England footballers and had some very technical hurdles. Such as uponor systems with NuHeat stats, weather compensators and advanced circulatory dynamics.
Low voltage varies from 8-24 with manufacturers so isn't always compatible.
I've had endless nights of lost sleep, racking my brain for anything I may have missed,
It is this simple....as a client, if your able to notice problems, have difficulties or encounter operational discomforts that can't be rectified with the touch of a few buttons...your installer is an amatuer