UFH by Wunda in my new built

[Prashanth]

Hi All,

new to this forum. I see many experts here provide lot of advice on UFH.

I’m buying a new property and as many advice ufh is the best thing and worth to establish on new built properties or if someone doing a house refurbishment as cost of heating will be less off course there will be a breakeven in cost after few years counting the cost of establishing it over cost of running on already established radiators.

 

I have been provided with the below zone layout from Wunda and to hide everything out I thought best place is to establish the manifold under the stairs. 
Any comments on this please?

just give you additional info, the boiler is located at the top right corner of the provided map downstairs and the hot water tank is placed in the airing cupboard upstairs (CYL).

Any suggestions if it is still practical enough to establish the manifold under the stairs? Or do I need to put this in the kitchen at bottom left of the blue zoned area (loop 1-6) where the pipes can go straight just in front of the airing cupboard?

also any professionals here who could take this job in Gloucestershire for establishing system for me including laying the insulation boards?

 

31651_Prashanth Kanatala_250214_Wunda.pdf

[JohnMo]

7 hours ago, Prashanth said:

cost of heating will be less off course

Welcome.

 

Would like to challenge the thought that UFH will cost less. With UFH you have greater downwards heat losses when comparing to radiator systems. Even with very good insulation.

 

Is you ground floor insulated? As I noticed the Wunda quote is for a 20mm system. As an overlay system, every floor covering comes up, all skirting are removed, all doors are shortened etc. it isn't a small job.

 

I would really stay with radiators, but make them work well. The best system being a low temperature radiator system. Ideally you would convert the boiler to run priority demand hot water and have weather or load compensation for heating and high temp for cylinder heating. Move away from thinking zones, boilers just don't like it, they run poorly and this applies to UFH and radiator systems.

 

[Prashanth]

Thank you for the reply John.

There is no additional insulation apart from the standard concrete base a builder will provide. I thought with new building regulations there is minimal heat loss because of the thick concrete foundations they provide.
Yes, the quote from Wunda is for 20 mm rapid response main board.

i agree all the flooring comes up by at least 20mm (uFH) + 10mm (porcelain tiles).

Also I understand skirting needs to be removed and doors needs trimming and I will implement my bit of my DIY skills.

The reason why I want to go UFH is, I currently live in a small house and because of the old parents I have to keep the room temp to 22 - 23 degrees c. Considering the new home is big that I’m moving to and to keep the entire house to 22 - 23 degrees C is going to be more expensive. 
Thought if I have Wet UFH I can control the temperatures in rooms and leave 17-18 degrees C on unused rooms.

I thought of going for electric UFH, but thought wet UFH is more cost efficient over electric.

Also I’m not sure if I can have wet UFH in addition to the radiator heating. Something like keep the radiator heating active, so that I can switch to UFH or radiator heating. Is it something possible, if yes is it a huge additional work from plumbing side?

also for Wunda UFH they are going to provide perimeter strip for this I need to remove the skirting board and stick this perimeter strip along the boarders. Can anyone suggest is it mandatory or can I skip this and just lay the heat boards aligning to the skirting board?

 

[Prashanth]

Sorry 22-23degrees. It’s a typo

Edited February 21 by Nickfromwales
Typo fixed :)

[marshian]

I'm with @JohnMo 

 

Heat loss is Heat Loss - doesn't really matter that much if you provide the heat with a radiator or underfloor

 

The advantage of underfloor over a radiator is a large surface area to emit the heat so a lower temperature can be used to transfer the heat.

 

However if your boiler cannot go down to that temperature then you need mixer manifold to drop the temp down to whatever the heat loss of the room requires

 

If you have other floors with radiators that need higher temps you are very likely to be running the boiler at a higher temp anyway.

[JohnMo]

53 minutes ago, Prashanth said:

Considering the new home is big that I’m moving to and to keep the entire house to 22 - 33 degrees C is going to be more expensive. 

Don't be fooled by advertising. It mostly bull sh** to catch you out.

 

If a house needs 6kW to keep it warm it needs that regardless of heat source.

 

Ripping a new house apart is just expensive and a waste of time and effort. If it's an actual new house they have to install a low temperature radiator system anyway. So check they have are doing so. Ask questions about how it's installed 

 

Is S, Y, X or W plan? Or is a combi boiler?

 

What make and model?

 

Post the answers.

 

You are likely to line Wunda's bank account, empty yours and gain a big fat zero on running costs gains

 

[Prashanth]

I have been researching on this UFH since last few months. Although I’m bit tight with the money I thought it’s one time investment to have that extra comfort with UFH. 
now looking at your views I’m halfway thinking of dropping the plan of having UFH.

It’s was gonna cost me £6500 including the material from Wunda and installation. 
it will be slightly cheaper if I go with electric UFH and I don’t have to rip any skirting board off.

now I need to sit down and do the cost of establishing electric UFH. Please suggest your opinion on electric UFH.

Also, I have plan on setting the solar panels in future.

Also to answer your questions,

the builder is establishing 3 heat zones with 3 thermostats.

1 for the master bedroom,

1 for the other 3 bedrooms

and 1 for the entire ground floor. 
if I’d decide to go with wet UFH I would assume the plumbing engineer would disconnect supply to entire ground floor radiators and connect this ground floor zone to the manifold for UFH.

@JohnMo unfortunately I don’t know which plan it is  (x,Y, S or W). I’m sure it is a heat only boiler. Make is IDEAL 18 kw.

they are providing a hot water tank in the airing cupboard.

Also I didn’t know there will be something like low temp radiators. Thought it is a standard radiator.

 

 

Edited February 21 by Prashanth

[marshian]

I don’t think I’d be entertaining using direct electric to heat rooms when I had a gas boiler and rads - the running costs are 3 x that of gas 

 

maybe for a bathroom floor thats intermittently heated for comfort factor I’d consider it but in that case it would be a luxury not a necessity 

[Prashanth]

We are interested in porcelain tiles for our ground floor flooring. Because it’s generally cold hence we wanted to go for UFH.

[Nickfromwales]

1 hour ago, Prashanth said:

I have been researching on this UFH since last few months. Although I’m bit tight with the money I thought it’s one time investment to have that extra comfort with UFH. 
now looking at your views I’m halfway thinking of dropping the plan of having UFH.

It’s was gonna cost me £6500 including the material from Wunda and installation. 
it will be slightly cheaper if I go with electric UFH and I don’t have to rip any skirting board off.

now I need to sit down and do the cost of establishing electric UFH. Please suggest your opinion on electric UFH.

Also, I have plan on setting the solar panels in future.

Also to answer your questions,

the builder is establishing 3 heat zones with 3 thermostats.

1 for the master bedroom,

1 for the other 3 bedrooms

and 1 for the entire ground floor. 
if I’d decide to go with wet UFH I would assume the plumbing engineer would disconnect supply to entire ground floor radiators and connect this ground floor zone to the manifold for UFH.

@JohnMo unfortunately I don’t know which plan it is  (x,Y, S or W). I’m sure it is a heat only boiler. Make is IDEAL 18 kw.

they are providing a hot water tank in the airing cupboard.

Also I didn’t know there will be something like low temp radiators. Thought it is a standard radiator.

 

 

Hi.

 

Firstly, completely remove any idea of using electricity to heat this home....especially at those temperatures!!! It would bankrupt you to burn electricity to provide space heating. For room temps at or above 22^oC you need to stay on gas.

 

Solar panels will have near zero affect on space heating; in winter a 4kWp solar PV system will have an average output of 0.4kWp, just enough to run a few background items. If you have a hot water cylinder and solar PV, ensure you ask the PV company to include a solar PV diversion controller to provide "free" hot water all summer vs exporting your excess generation to 'the grid'.

 

If you want different temps in different rooms you will need 1x thermostat for each room / space, so 1 per bedroom minimum, possibly 1 more for the other area(s). When you zone heating like this it is a problem for the boiler, because when UFH is near to the desired temperature the demand on the boiler is very low, so to deal with that you may need a better boiler which can modulate down to match this. It is also very likely that you would benefit from a small buffer tank to assist the boiler to live a long life, and to stay in the best operating temperature range to promote full condensing effects / efficiencies.

 

Some of the advice given by others above suits a well-insulated, energy efficient house, and I suspect yours does not / will not fall into that category. Please correct me if I am wrong. If I am right, then you CAN install UFH, but you will hear the downsides from us lot, but if you want it it can be done, be comfortable, and do what you ask, it'll just be less energy efficient vs radiators and quite disruptive to install properly.

 

"Can it be done?" = yes.

"Should I do it?" = up to you, your budget, and what your energy bills will look like going forwards.

 

Ideal boilers I used to fit for landlords / agents in rental properties btw. If this is a forever home I would fit something far superior for not a huge amount of additional money.  

[Nickfromwales]

5 minutes ago, Prashanth said:

We are interested in porcelain tiles for our ground floor flooring. Because it’s generally cold hence we wanted to go for UFH.

Porcelain works well with UFH as it balances the heat delivery a little better than wood etc, but please check with Wunda as the overlay boards sometimes need an additional layer of backer boards set on top into tile adhesive, prior to installing the tiles. That would add at least another 10mm to the finished height. I think they do a 400micron panel which you can tile directly to, but you'd need to ask them today about what they offer as it was a while since I looked at their system and they may say different.

 

3 hours ago, Prashanth said:

There is no additional insulation apart from the standard concrete base a builder will provide. I thought with new building regulations there is minimal heat loss because of the thick concrete foundations they provide.

Please explain what the specification for this concrete floor is proposed to be. How much concrete and how much insulation. British Building regs will mandate the insulation so you will definitely be having some.

 

The concrete will not insulate, it will suck the heat out of your UFH and send it to the earth below, so you cannot fit UFH over an uninsulated  concrete slab. 👎

[JohnMo]

2 hours ago, Prashanth said:

£6500

That's a lot of money. Definitely just leave as is from builder for now. See how it runs. Boiler supports weather compensation out the box. So I would move to this with radiators.

 

You may need to change the odd radiator to get system running a nice low temperature.

 

[Mike]

On 21/02/2025 at 00:47, Prashanth said:

I’m buying a new property and as many advice ufh is the best thing and worth to establish on new built properties or if someone doing a house refurbishment as cost of heating will be less off course there will be a breakeven in cost after few years counting the cost of establishing it over cost of running on already established radiators.

In terms of comfort, UFCH provides a different quality of heat (even temperatures, with little variation in temperature between the floor and ceiling) compared to radiators (several degrees temperature difference from floor to ceiling + circulation of the air) and, when feasible, I choose it every time.

 

Economically, the position is more complex. All things being equal UFCH is generally reckoned to use less energy, but things are rarely equal:

• The floor will be hotter and can therefore loose additional heat, so you need good floor insulation to compensate for this - preferably significantly more than you would get in a standard new-build, though at least recent regs require some heat resistance. On the other hand, high temperature radiators placed on outside walls - as they often are - also cause additional heat loss to the outside.
• The very low variation in temperature between floor and ceiling with UFCH means that the overall temperature of the rooms can be lower, so using less energy than radiators, which tend to be turned up at least a couple of °C higher to deliver a comfortable temperature at sitting height (and more than that if the radiator controls aren't well chosen or controlled).
• It also depends on occupancy and when you use your heating; with radiators it's easy to heat only during hours of use as they can deliver heat quickly (at least from a gas boiler), whereas with UFCH the whole system takes several hours to respond to a change in settings.

 

On 21/02/2025 at 16:18, Prashanth said:

if I’d decide to go with wet UFH

Wet UFCH is the preferable - you can then use and switch between any suitable heat source over the life of the pipes, whether that's a gas boiler, heat pump, district heating, electricity, or whatever.

[JohnMo]

This is a different take to the UFH argument. But you will need to run 24/7 to keep floor buffered with heat. Which is how you should run UFH really.