Long term UFH problems: please help :-(

[jonpaul31]

Hi Folks,

 

This is my first post and sorry it is long: please be patient with me as this has been a long term problem. The below has taken a long time to get to due to complacent builder not wanting to help and heating contractor delays who could only carry out tests in winter, etc. As such, for simplicity I will just stick to the facts regardless of the duration it has taken.

 

I bought a new build flat in 2016 with a NIBE F205P heat pump and underfloor heating (UFH). I always wanted to get a nice carpet fitted and I was aware of the combined underlay and carpet tog value rule of not exceeding 2.5. However, I stupidly laid combined tog of 2.8 and had heating issues- the flat would never reach the desired temp of 21 degrees and it was rinsing my electric. In light of this, I changed my carpet to Revlon 90 Scorpius Invictus (tog 1.3) and kept my Duralay King UFH underlay (tog 0.8) for a combined tog of 2.1- it has made no difference whatsoever and the same problems occur even on relatively mild winter/autumn days. On freezing cold days, the flat never stands a chance and is often be 3 degrees off target temperature. Please keep in mind that this problem happens with the NIBE on both setting 1 i.e. heat pump, and 2 i.e. heat pump and immersion (apologies if terminology is slightly incorrect there). So I have a double whammy of no heat but rinsing electric because it doesn't hit the thermostat temp of 21 degrees.

 

Last winter, the heating contractor (who despite the long duration, has tried to be helpful through constant checking, servicing, etc) arranged an investigation of my problem by a third party using both a thermal camera test and laser thermometer. This was done to see if my carpet and underlay was the problem. This test revealed that with the carpet and underlay pealed back, the bare naked wooden floor was outputting 23 degrees. The independent chap informed me that if the system was designed to keep the rooms at 21 degrees, there would need to be a differential of at least  +5 degrees meaning the bare floor needed to be 26 degrees minimum to punch through the wooden floor, underlay and carpet. In that moment, the 'heating contractor' who installed it revealed that the 'builder' instructed them to install the heating water pipes “UNDERNEATH” the sound proofing.

 

Sorry but does that not sound like madness? Surely this is why I am having problems and the usual rule of 'do not exceed tog 2.5' no longer applies because there is an extra barrier i.e. the sound proofing. So now I cannot predict what combined tog to install as clearly the heating is not producing the necessary heat, arguably because of the sound proofing being laid on top! I cannot even install hard flooring as it is against the terms of my lease. 

 

I really do not know what to do as no matter what setting I have the NIBE on, it never reaches temperature and therefore rinses the electric, especially on setting 2. 

 

I was thinking of contacting NHBC about this as I still have six years left and surely this is a building cock up. My flat is relatively small and as a reference, my electric was £327 for the 3 months of October to January. That is far too much for just me and it’s gonna seriously affect ability to sell or I will get some serious comeback since these faults need to be declared on property information forms when you sell.

 

Any advice? I really am in a quandary ☹️.

 

Thank you so much.

 

John

 

[ProDave]

No 1.  Try rolling the carpet away for a week.  does it heat up properly then?  If not then the carpet is not the issue.  That needs establishing to stop the "blame game"

 

If you can establish it still does not heat the property properly without the carpet then you can move forward.

 

Do you have the instructions for the heat pump and understand how to at least read things from it's controller?

 

What was the EPC rating or any information you might have from a SAP report which will have been needed for building control. If you don't have this ask the developer that solf the property to provide this.

 

I see your unit is an "exhaust air heat pump" so it is combined with the ventilation system and extracts heat from the exhausted air to heat the property.  It is only a VERY low power system, so only works with a small well insulated property.  I only know of one property near me that had a similar unit and found it wanting. He eventually gave up and replaced it with a conventional air source heat pump with an outside unit.

 

Where abouts are you and just how cold is the outside temperature where you are?

 

The immersion heater thing, that is used to supliment the limited heating ability of this unit when it gets too cold for the heat pump on it's own to manage.  It is then a stark choice between pay more for the heating or go cold.

 

[jonpaul31]

Hi Dave,

 

Thank you for your reply.

 

To answer your questions:

• I am based in Weymouth, Dorset on the south coast.
• By means of example, yesterday it was 5 degrees outside and the internal temperature was 19 degrees at 10:00 am. Keeping in mind that the UFH turned on at 04:00 am and had been on a while. The temperature was 0-2 degrees last week and it was 16-17 degrees in the flat.  
• The SAP energy rating for this property is 84.
• I had the carpet pealed back just over half way for a week last year and whilst it got closer, it still did not reach target.
• I do have the instructions and the only guages I can read are water temp (54 degrees) and pressure (1.3 bar). At last service, the heating engineer said that the system is running optimally and the return water temp was only 1 degree less than outgoing.

Regarding the carpet issue, I thought what the third party said during his naked floor investigation was interesting (regarding the required +5 degree differential), as was the sound proofing being on top of the water pipes. Do you have any thoughts on that? That surely is not standard practice is it?

 

I think what might be happening is the soundproofing is blocking heat, which then changes the standard rules regarding UFH and tog. The third party said whilst you can use carpet with UFH, it will still offer a degree of thermal resistence and that, combined with sound proofing, it is likely to be a hinderence to the system working properly regarding floor heat.

 

Now, I am on the top floor (there is a ground and two floors). The third party also said that whilst hot air travels up, it will move down if it is trapped and I am likely heating the downstairs flat on 1st floor. This is supportted by the fact their bills are cheaper (same size flat). However, in turn he said they may also have same problem since their sound proofing is also installed over the top of the UFH pipes. As such, they are likely heating the ground floor flat. This is also supportted by the fact the ground floor flat said they are extremely warm. Furthermore, the ground floor does not have sound proofing in floor so they will be getting the right heat from their UFH, as well as potentially the downward heat from the first floor flat. Now, obviously I do not have anyone above me so the consistency in this installation chain stops with me. Incidentally, my kitchen has vinyl flooring and whilst it is not cold, it isn't exactly warm. By comparison, the ground floor neighbour's kitchen floor was 'very' warm when I went in there one day. They would not presummibly have sound proofing over the top of their UFH pipes. 

 

Even if the carpet was an issue and I replaced for third time, the sound proofing issue throws a curve ball into the mix as I would never be able to guess what the right tog should be. It is 2.1 now and should be working to be honest. Unless that sound proofing is an issue i.e. it is over the top of the UFH. Remember, that is a fact by the way as the heating contractor was there in my home at the same time as the third party UFH chap. He said the builder asked them to install UFH before the sound proofing was laid. All strikes me as odd.

 

Thank you for your help so far, Dave.

 

John

[ProDave]

In a new build flat, the fireproofing and sound proofing required will be under the floor between your floor and the flat belows ceiling.  Any floor covering you choose is just that, a floor covering to give the look and feel that you want, not to add sound proofing.

 

I still think the carpet needs to be rolled up to expose almost all the bare floor as a test.  Until you have done that, the other guys will keep coming back to that as an excuse for the poor performance.  It needs to be ruled out conclusively and beyond doubt before you can move on.

 

I would buy a cheap infra read thermometer, one like this as an example https://www.ebay.co.uk/itm/UK-Infrared-Non-Contact-Forehead-Thermometer-Temperature-Measurement-Gun-Baby-IR/184449918836?hash=item2af2126774:g:A6AAAOSwJodfYbFj

 

With that you can measure what floor temperature is actually being achieved, and look at things like wall and ceiling temperatures.

 

Another thought on the carpet.  You don't know how much and  what type of insulation is under the floor between you and the flat below.  Your carpet will have the effect of elevating the temperature of the floor which may have the effect of making more of that heat go down to the flat below.

 

 

 

[Gone West]

3 hours ago, jonpaul31 said:

This test revealed that with the carpet and underlay pealed back, the bare naked wooden floor was outputting 23 degrees.

 

2 hours ago, jonpaul31 said:

the only guages I can read are water temp (54 degrees) and pressure (1.3 bar)

 If the flow temperature is 54C and the bare floor temperature is 23C then it seems to me that there is a lot of heat being lost downwards. An explanation for that, is as you suggest, that the sound insulation is preventing much of the heat from reaching the floor. It would be useful to have a drawing or details of the whole of the floor construction.

[Temp]

24 minutes ago, ProDave said:

I still think the carpet needs to be rolled up to expose almost all the bare floor as a test.  Until you have done that, the other guys will keep coming back to that as an excuse for the poor performance.  It needs to be ruled out conclusively and beyond doubt before you can move on.

 

+1

 

3 hours ago, jonpaul31 said:

The independent chap informed me that if the system was designed to keep the rooms at 21 degrees, there would need to be a differential of at least  +5 degrees meaning the bare floor needed to be 26 degrees minimum to punch through the wooden floor, underlay and carpet. 

 

In awful lot depends on how well insulated the house is, double or tripple glazing etc. Mine built around 2006/7 needs much higher flow temperatures than either suggestion to achieve 20C room temperatures in some rooms where we have 21mm wood floors over UFH. 

 

Based on your numbers.. 

 

A TOG of 2.1 is equivalent to an R-Value of 0.21 or U-Value of 1/0.21 = 4.76  W/m²·K. 

 

The power dissipated per square meter would be U-Value * Temperature difference

 

At 21C..

= 4.76 * (23-21) = 9.5 W per square meter.

 

At 26C''

= 4.76 * (26-21) = 23.8 W per square meter.

 

I'm not very familiar with the SAP/EPC figures but if you have that info perhaps someone can comment if this is all consistent.

 

 

 

 

 

 

 

 

[Temp]

1 minute ago, PeterStarck said:

 

 If the flow temperature is 54C and the bare floor temperature is 23C then it seems to me that there is a lot of heat being lost downwards. An explanation for that, is as you suggest, that the sound insulation is preventing much of the heat from reaching the floor. It would be useful to have a drawing or details of the whole of the floor construction.

 

I wonder what the return temperatures are like given..

 

3 hours ago, jonpaul31 said:

In that moment, the 'heating contractor' who installed it revealed that the 'builder' instructed them to install the heating water pipes “UNDERNEATH” the sound proofing.

 

[Gone West]

8 minutes ago, Temp said:

I wonder what the return temperatures are like

 

2 hours ago, jonpaul31 said:

At last service, the heating engineer said that the system is running optimally and the return water temp was only 1 degree less than outgoing.

Something odd going on.

[ProDave]

IF this has been done properly, there will be a proper under floor heating manifold with a pump and lots of valves hiding away in a cupboard somewhere.  Have you seen such a thing?

 

This particular heat pump system does seem very basic, very little in the way of controls, settings or readings, even the instalation manual does not give a lot away.

 

Yes agree the above statement about sound insulation and UFH pipe positioning sounds very strange indeed.

[SteamyTea]

Welcome.

As you have a top floor flat, you also have roof losses to contend with.

But roll the carpet up and stand it up in a corner. Much of this will be a detection game.

 

I had a holiday home in Turton Street. Wish I had kept it till the Olympics came along. No one thought that Weymouth would host the sailing in 1990.

[Nickfromwales]

Unless the UFH pipes are directly under the finished floor, in aluminium spreader plates or other such purpose made diffuser, this is not going to improve ever. 
Ive seen umpteen ‘builder executed’ UFH fack-ups, including UFH pipes just loose under the floors in the joist voids, boiler set at 80oC and TMV set to max flow temp etc. It’s really unbelievable that anyone thinks they can just throw this in ( especially when it is a heat pump install ) and it’ll work. 
This is a ‘floor up’ job by the sounds of it.  

[jonpaul31]

Wow- thanks for the replies, Folks. Let me see if I can work this quote tool so I can address everything.

 

2 hours ago, ProDave said:

In a new build flat, the fireproofing and sound proofing required will be under the floor between your floor and the flat belows ceiling.  Any floor covering you choose is just that, a floor covering to give the look and feel that you want, not to add sound proofing.

 

I still think the carpet needs to be rolled up to expose almost all the bare floor as a test.  Until you have done that, the other guys will keep coming back to that as an excuse for the poor performance.  It needs to be ruled out conclusively and beyond doubt before you can move on.

 

I would buy a cheap infra read thermometer, one like this as an example https://www.ebay.co.uk/itm/UK-Infrared-Non-Contact-Forehead-Thermometer-Temperature-Measurement-Gun-Baby-IR/184449918836?hash=item2af2126774:g:A6AAAOSwJodfYbFj

 

With that you can measure what floor temperature is actually being achieved, and look at things like wall and ceiling temperatures.

 

Another thought on the carpet.  You don't know how much and  what type of insulation is under the floor between you and the flat below.  Your carpet will have the effect of elevating the temperature of the floor which may have the effect of making more of that heat go down to the flat below.

 

 

 

 

Yes I understand about about where the sound proofing should be, but to be clear it is not where it should be. It is not under the UFH, it is situated above it, between my floor and the UFH.

 

If I roll back the carpet and underlay, it still doesn't really eliminate it as the problem, even if the room did warm up to target temp. The reason being is this: the sound proofing cock up and carpet/underlay are both co-variables. You would need to eliminate both to exclude the other by introducing them back in, one at a time. For example, I could  peal back carpet/underlay, get a positive result, and then put a combined tog of 1.0 down after. The same problem could occur if the sound proofing was the issue, since any flooring will provide a degree of thermal resistence, and it could breech what would be considered the threshold. 

 

As for buying thermometer and testing floor, this has already been done very comprehensively. Hence the comments about the need for a +5 degree differntial. The naked floor (I have been told) must always be at least 5 degrees hotter than the temperature for which the UFH was designed to run at.

 

1 hour ago, PeterStarck said:

 

 If the flow temperature is 54C and the bare floor temperature is 23C then it seems to me that there is a lot of heat being lost downwards. An explanation for that, is as you suggest, that the sound insulation is preventing much of the heat from reaching the floor. It would be useful to have a drawing or details of the whole of the floor construction.

 

Yes this is what I thought- the evidence is kind of there in the example I gave about the ground and first floor flats. Also, I forgot to say that every flat on top floor is having exactly the same issue and they also have a slightly thinner carpet/underlay supplied by builder (I had to do mine myself because I knocked them down £5k at purchase. 

 

2 hours ago, Temp said:

 

I'm not very familiar with the SAP/EPC figures but if you have that info perhaps someone can comment if this is all consistent.

 

I could post this I beleive- it is in my flat file.

 

1 hour ago, PeterStarck said:

 

I wonder what the return temperatures are like

 

If I recall correctly, it is 55 outgoing and 54 on the return.

 

1 hour ago, ProDave said:

IF this has been done properly, there will be a proper under floor heating manifold with a pump and lots of valves hiding away in a cupboard somewhere.  Have you seen such a thing?

 

This particular heat pump system does seem very basic, very little in the way of controls, settings or readings, even the instalation manual does not give a lot away.

 

Yes agree the above statement about sound insulation and UFH pipe positioning sounds very strange indeed.

 

The manifold is situated right next to the NIBE. I am pretty confident that the heating company have it set up optimally. But I guess that makes no difference if you have nicely tight sealed layer of sound proofing over the top of the UFH. And that's before we get to the floor, underlay and carpet 

 

1 hour ago, SteamyTea said:

Welcome.

As you have a top floor flat, you also have roof losses to contend with.

But roll the carpet up and stand it up in a corner. Much of this will be a detection game.

 

I had a holiday home in Turton Street. Wish I had kept it till the Olympics came along. No one thought that Weymouth would host the sailing in 1990.

 

We also checked the insulation in roof and the builder laid more. When checked by heating contractor, they said it was ample. Not convinced the rolling of carpet will help hear- see my comment in this post about co-variables- we would need to elimante the sound proofing and carpet collectively and reintroduce one at a time. 

 

23 minutes ago, Nickfromwales said:

Unless the UFH pipes are directly under the finished floor, in aluminium spreader plates or other such purpose made diffuser, this is not going to improve ever. 
Ive seen umpteen ‘builder executed’ UFH fack-ups, including UFH pipes just loose under the floors in the joist voids, boiler set at 80oC and TMV set to max flow temp etc. It’s really unbelievable that anyone thinks they can just throw this in ( especially when it is a heat pump install ) and it’ll work. 
This is a ‘floor up’ job by the sounds of it.  

 

I can confirm that the ground floor flats have the aluminium spreader plates and the first/second floor have some sort of foil matting (as told by heating contractor). The UFH pipes are not directly underneath the floor. Sounds like a right balls up to me. This is of course if the heating contractor is telling the truth about the sound proofing and I do not really have any reason to beleive not.

 

Thanks so much for your replies everyone. I can assure you it is very appreciated. This has been the cause of much stress. I do hope NHBC might be able to offer some relief here.

[ProDave]

If you are really SURE the sound proofing is in the wrong place, then it is a move out, floor up and re do it job, at the builders expense if it was their error.

 

Get the builders to lift a section of the floor to investigate to be sure (and post pictures of that as well)

 

Can you post a picture of the UFH manifold for completeness?

[SteamyTea]

12 minutes ago, jonpaul31 said:

2 hours ago, PeterStarck said:

 

I wonder what the return temperatures are like

 

If I recall correctly, it is 55 outgoing and 54 on the return.

If that is correct, it sounds like the pipes are just floating in a void, or well insulated.

 

I think with the NHBC, you have to give the original builder the opportunity to sort the problem, then you have to argue with the NHBC, and loose your claim.

You may find it does not cover heating system anyway.

[Nickfromwales]

13 minutes ago, ProDave said:

Get the builders to lift a section of the floor to investigate to be sure (and post pictures of that as well)

+1. Spare bedroom maybe? 

[jonpaul31]

23 minutes ago, SteamyTea said:

If that is correct, it sounds like the pipes are just floating in a void, or well insulated.

 

I think with the NHBC, you have to give the original builder the opportunity to sort the problem, then you have to argue with the NHBC, and loose your claim.

You may find it does not cover heating system anyway.

All of the tests above were initiated by builder. They essentially asked the heating contractor to investigate and sort, who then arranged a third party to provide their expertise. I informed the builder of this test and lack of progress with my complaint and he complained that I shouldn’t be trying to arrange independent tests and that it was now my problem. But I didn’t- it was the bloody heating contractor. And now to add insult to injury, the builders shut up shop last year. This has been going on since 2016. It’s a total disgrace. 
 

22 minutes ago, Nickfromwales said:

+1. Spare bedroom maybe? 

 

Yes I think I will he investigating under the floor so I can post. Although to be fair, the heating contractor has already verified this. But I guess you mean to eliminate whether he is telling porkies. 

[SteamyTea]

8 minutes ago, jonpaul31 said:

And now to add insult to injury, the builders shut up shop last year. This has been going on since 2016. It’s a total disgrace. 

His PI, or the Architects PI may still be valid, and have you had a word with Building Control?  They were helpful when I was down there.

[jonpaul31]

7 minutes ago, SteamyTea said:

His PI, or the Architects PI may still be valid, and have you had a word with Building Control?  They were helpful when I was down there.

Not yet no. I wanted to get all my ducks in a row first as it were. 
 

The whole thing is a mind circus. Whilst I say the heating contractors were helpful, they did not reveal the sound proofing observation until the 11th hour. Prior to that, they were even asking if I had a partner living in my two bed flat because UFH systems are finely tuned and consider number of people. I mean it’s a joke. My hob after cooking for 30 minutes warms the place up better than the thing that's sole purpose is to warm the property. You couldn’t make it up. ?

[TonyT]

Cut your losses and get it fixed by someone else or walk away

 

 

NHBC are useless

main contractor down the tubes

heating  engineer’s contract with builder.

heating engineer will blame builder.

you will get stressed and upset emailing and phone calls

It’s never going to be resolved to your satisfaction.

 

 

is the floor a fire compartment?

complicating things further?

lifting flooring, glued down?

damaging joists

Cracking ceiling in flat below.

 

if the oven heats the place up, then get a 3kW fan heater leave the ASHP as is and sell the flat

 

 

[Nickfromwales]

52 minutes ago, TonyT said:

Cut your losses and get it fixed by someone else or walk away

A couple of years ago, I saw about £30k worth of poorly rendered facades being replaced under NHBC cover. For the cost of a few calls and emails it's most definitely not a waste of time or effort.

 

53 minutes ago, TonyT said:

if the oven heats the place up, then get a 3kW fan heater leave the ASHP as is and sell the flat

Have you ever considered a position as a motivational speaker? 

[SteamyTea]

1 hour ago, TonyT said:

3kW fan heater

Most domestic ones are 2 kW, 3 kW will melt the plug and socket.

I got a nice 400W one from the range, keeps the place warm in the shoulder months.

[jonpaul31]

I agree- a few phone calls to NHBC would be beneficial. Let’s face it, if the sound proofing issue turns out to be real, and you are all saying it is not standard practice, then they surely haven’t got a leg to stand on. 

I already bought a 2.8 kw heater for living room and a 600-800w one for bedroom and office (second bedroom) if needed. I’m not convinced it’s gonna be cost effective though, although damn site cheaper than the NIBE.  

34 minutes ago, Nickfromwales said:

Have you ever considered a position as a motivational speaker? 

??

[TonyT]

27 minutes ago, SteamyTea said:

Most domestic ones are 2 kW, 3 kW will melt the plug and socket.

I got a nice 400W one from the range, keeps the place warm in the shoulder months.

https://www.argos.co.uk/product/4153843
 

plenty 3kW heaters around

[TonyT]

don’t fancy the motivational speaking, I’m firmly planted in the real world.

[Temp]

You might also consider talking to a solicitor if the NHBC can't help. If there is sound insulation over the pipes then someone has been negligent. Keep the reports you have had done and possibly get an expert to comment specifically on the sound insulation issue.