Underfloor heating doesn't get warm

[AnonyDIYnot]

Hi
I had a kitchen extension built ~8 years ago with wet underfloor heating. From the start I knew it wasn't working properly - the new underfloor heating kept competing with the old radiator system in the rest of the house. The builders came back multiple times telling me I was wrong. Eventually, I spent over £1k getting the installation fixed - a valve was missing to separate the two systems and there was an electrical mistake that I cant remember.
Unfortunately, my extension still doesn't get above 16-17 degrees when it's cold (if heating is on all day).
The boiler can be on full blast and the floor doesn't feel that warm.
The cupboard containing the underfloor heating console gets toasty, the boiler is always burning (at huge cost), I have had 3 or 4 different "experts" out over and over and over again. They have spent hours studying my heating system (costing hundreds of pounds).
I have tried to understand what might be going on by googling. I really need expert advice but so far experts have not helped and have cost me a lot of money.
I know this is vague but I appreciate any thoughts / advice.
Could it be that the tiles in my extension do not transmit heat? Or is that ridiculous?

Thank you.

 

[big-all]

Underfloor is designed for use in excellently insulated rooms and 24h operation if you want sporadic use and a quick heat up you need radiators as well

 

[AnonyDIYnot]

Hi big-all thank you for your message. I have wondered about this. I have recommended friends install radiators as well as underfloor heating as a result of my experience. However, some people rave about their UFH - they claim not to have it on all the time.
In your experience, what temperature should UFH be set at to get optimal heat maintenance from it?

 

[big-all]

no expert but its somthing like 22 to 25degrees hense the slow build up but wait for others to give a more exact answer

 

[BlueLoo]

Hi
I had a kitchen extension built ~8 years ago with wet underfloor heating. From the start I knew it wasn't working properly - the new underfloor heating kept competing with the old radiator system in the rest of the house. The builders came back multiple times telling me I was wrong. Eventually, I spent over £1k getting the installation fixed - a valve was missing to separate the two systems and there was an electrical mistake that I cant remember.
Unfortunately, my extension still doesn't get above 16-17 degrees when it's cold (if heating is on all day).
The boiler can be on full blast and the floor doesn't feel that warm.
The cupboard containing the underfloor heating console gets toasty, the boiler is always burning (at huge cost), I have had 3 or 4 different "experts" out over and over and over again. They have spent hours studying my heating system (costing hundreds of pounds).
I have tried to understand what might be going on by googling. I really need expert advice but so far experts have not helped and have cost me a lot of money.
I know this is vague but I appreciate any thoughts / advice.
Could it be that the tiles in my extension do not transmit heat? Or is that ridiculous?

Thank you.

Lots.of.photos.

 

[AnonyDIYnot]

Mine has never got above 18/19 without sunshine when I have had it on constantly all day. My next door neighbours are really happy with their UFH. I have no idea, I just know it's costing me a lot of money. Let's see if anyone else can advise further. Thank you though I appreciate your response.

 

[big-all]

not the room the water temperature that has to be hotter to transfer heat the room stat doesnt control the water temperature [the manifold mixing hot and cold does that] just the demand for heating and when that drops it cuts off
is the neighbour better insulated / on 24hrs??
with heating from the same source be it electric /gas /other the difference in efficiency will be minimum as its energy in is equal to energy out with very similar transmission losses so any claims off " cheaper to run" or " more efficient" tend to be its colder or possible saving are theoretical and often more expensive to vastly more expensive iff you include new system costs

 

[stem]

The insulation below the UFH is also important, otherwise it will be heating the ground. As the new extension was only built 8 years ago I imagine building control would have checked and signed it off at the time. Do you know what insulation was used and how thick it is?

 

[Exedon]

Wet in screed type underfloor works really well depending on several things.
Insulation levels are correct
The pipework installation is at correct distance apart to give output required for room (needs proper heat loss calculations not guess me)
The heating is run with correctly with back set temperatures typically no more than 4C below required temperature eg if you want room to be at 20c room should never be cooler than 16C.

 

[Lower]

Hi big-all thank you for your message. I have wondered about this. I have recommended friends install radiators as well as underfloor heating as a result of my experience. However, some people rave about their UFH - they claim not to have it on all the time.
In your experience, what temperature should UFH be set at to get optimal heat maintenance from it?

I have the thermostat in the room with the underfloor heating set to 19 degrees. The water circulating in the underfloor heating pipes is at 30 degrees. The heating comes on approx 4 hours in the morning and then might come on for 2x 20 minute periods during the rest of the day. That keeps the room at a steady temperature all day and it works very well.

Its installed in a newly built extension with 100mm of celotex insulation under the pipes and 50mm of screed on top and its a well insulated room.

Is your underfloor heating on a seperate circuit and thermostat to the rest of the house?

 

[lostinthelight]

Is your heating loop Teed off the heating circuit after the main pump and has its own pump as well?

 

[AnonyDIYnot]

Thanks to everyone for comments. FYI I think heat is getting lost when weather is cold. Increasing the water temp did not work when it was freezing cold outside but it did have a marked difference when the weather was less cold. Very annoying but I am now confident there is nothing wrong at manifold. If I want to fix it I need to take up the floor. Thanks again for advice.

 

[Diver Fred]

Can you obtain an Infra Red image of the floor when the heating is on to post on here?

 

[AnonyDIYnot]

Diver Fred, I have never heard of this. I did a quick google after seeing your message, it has never been suggested to me but makes complete sense. I'll look into getting it done, thank you.

 

[Mr Chibs]

What's the central heating water temperature? Presume there is a blending valve on your UFH, perhaps you could turn this a 'notch' hotter.