First house, want to retrofit Underfloor Heating. Many Questions

[OnlyHumanHere]

Hi there,


So first things first, just bought myself my first house . 1920's build in Wiltshire. Should have the keys to it next week, can't wait.


Floor plan




First problem is, no gas mains in the village. This means it currently has an immersion heater to supply hot water , storage heaters for heat and the oven/hob connected to gas bottles stored outside on the side of the house.


So, after doing a bit of research and planning with my wife, we want to scrap the storage heaters and go for water UFH with a free floating 8mm laminate flooring Something on the lines of this . Looking around, I think prowarm seem to do a good job with supplying all the parts we need, being bought from Theunderfloorheatingstore (regarded fairly highly online and seemed very helpful on the phone).


Now, my main concern is what to do with the heating element. I've spoken to a few specialists and I've been told either keep the immersion heater for the sink/bath water and get something like a 'Slim Jim' electric boiler for the UFH. Obviously the guy that recommended that was the website that sells it. However, again it's reviewed rather well and it'd be nice to keep all the product coming from one place.


Another plumber I spoke to recommended to scrap the immersion heater and get a combi boiler. He did say that if it was him, he would probably look at LPG combi boilers over an electric boiler for the long term cost saving (did a bit of research and yes, lpg is much cheaper than electric). However, when it comes to boilers, I'm completely lost as to what I need.


So my questions are...


* Keep the immersion tank or scrap it?
* Get an LPG combi boiler, electric combi boiler or just a stand along boiler for the UFH and keep the immersion tank.
* If I was to take the immersion tank out, should I put the new boiler in it's place? If so, would I need 1 or 2 UFH manifolds for each floor?
* I was thinking about putting the whole system (manifold and boiler) under the stairs, would that make sense?
* Apart from the kitchen (which is tiled) and the reception (which is original parquet), the rest of the house is carpeted, is it relatively straight forward to just rip the carpet up, lay down the floating floor, insert piping, cover and just throw the laminate on top?
* One guy I spoke to said I would probably need to manifolds, 1 for each floor. Is that right?
* rippiing up the Parquet and tiles in the kitchen, is there anything I should know before doing so?


I plan to try and get most the humping and dumping, laying the insulation for the piping, the piping and laminating myself, however I will be getting professional help for the installation and testing of the equipment.




Final Question, with multizone UFH...is the NEST thermostat (Gen 2) still a good option?






I hope I haven't made things too complicated.












TL: DR....Want to install UFH, in the UK, what is a recommended brand? Should I scrap my Immersion heater for an electric or LPG combi heater? Is it all worth it?

 

[UNG]

He said he's got 10k to spend on boiler, UFH and laminate - that's fairly healthy just for that element of the works, obvioulsy that will change if he does the job properly.

He's also said that this will be their forever home - that's a signicant statement - they will be paying energy bills forever.

What's the point of throwing in a cheap to install, cripplingly expensive to run heating system now - you only pay for a proper job the once, you'll be paying energy bills forever.

You are correct, it is the OPs money not ours to spend for him.

So what budget will he need for the rest of the work needed even an expensive installation could have high running costs


The problem as I see it is that little thought has been put into the on going costs of running the system, this really needs a bit more than beer mat planning and a wet finger in the air to find a cost effective solution to provide heating and hot water at an affordable cost.
I've seen it many times where people have jumped in with both feet only to find their chosen system is too expensive to run with no access to mains gas and the possible planning issues with utilising alternative energy sources this property is going to be an interesting design challenge for someone

 

[sean_ork]

So what budget will he need for the rest of the work needed even an expensive installation could have high running costs


The problem as I see it is that little thought has been put into the on going costs of running the system, this really needs a bit more than beer mat planning and a wet finger in the air to find a cost effective solution to provide heating and hot water at an affordable cost.
I've seen it many times where people have jumped in with both feet only to find their chosen system is too expensive to run with no access to mains gas and the possible planning issues with utilising alternative energy sources this property is going to be an interesting design challenge for someone

I've got no idea how much extra he will have to spend, maybe ask MW for one of his guesstimates.

I completely agree with the rest of your comments, thats the same point ive been making - its often a false ecconomy to install a heating system, with little regards to insulation/thermal bridges/air tightness. Competent spending on these will negate the need for any space heating, but that certainly will be a challenge in that building.

No access to mains gas is currently advantageous price wise for those who use LPG/Sec28, but who knows what it will cost in x years.

 

[UNG]

By my calculations and guesstimate, that's about 5k on digging up & putting back the floor.

I wouldn't like to guess what it would cost there are too many variables not least the possible structural issues of digging the floor out which would need to be assessed.
Looking at the location with double yellow lines on the road and what looks to be very limited or no parking there may be issues locating skips to remove spoil and taking delivery of concrete and other materials which could significantly affect costs if this has to be done out of normal hours

 

[OnlyHumanHere]

There's nothing structurally preventing proper wet UFH being installed, thats just money, effort and time - perhaps the disruption and need to have it all in with 2 months makes doing the job properly unrealistic.

There's no requirement to live in it until the job is done. We currently live in military married quarters so there's no rush...i'd just rather it all done in about 2 months.

 

[OnlyHumanHere]

How do you know that there's nothing structurally preventing it? With the age of the building there may be very limited foundations which may then require underpinning before the floors can be dug out far enough to get a concrete slab cast to then get a thick enough insulation layer down.

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful. Speaking to professionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

 

[OnlyHumanHere]

How can you tell that? As far as I can tell it's a 1920's built converted schoolhouse with a thatched roof in Wiltshire.
So it is not going to be like a fairly normal house as most normal houses weren't built as schools and thatch roofs are not all that common except in isolat dare as of the country.

It's not the thatched roof one...it's the white house.

 

[OnlyHumanHere]

Firstly I'd like to thank everyone for their comments, it's been good to see insight from both sides of the fence.

Having spoken with some specialists in Salsibury (though since we haven't got the keys yet, we haven't been able to get the some proper specialist advice)...I've told my wife to scrap the idea of putting ufh upstairs...since upstairs will be the guest room and my daughters room...there's no much need for the hassle....we'll just buy a heated play matt for our daughter it really matters. Like this but bigger (not sure why the photo is so big, apologies for that.

Like I said, there's no rush to move into the house, however I'm not a fan of tea breaks when a job needs doing so I expect things to be done in a timely manner. The beauty of being in the military is that I have a large supply of man power I can utilize for the price of a few crates of carling (they really aren't picky), which is nice.

This idea of needing to dig down to china to make sure i have miles of insulation under the UFH just isn't required...I'm not needing to warm up the ground surface, I'm wanting the heat to be reflected upwards....the beauty of floating floor on top of ufh IS that it heats up quickly and cools down quickly imo. If the room is cold, I want it to heat up quickly, there's little draft in the house so there's no worry of heat escaping...there's not even a chimney in the house which is the main reason why old houses are normally drafty. I plan to kit the house out with google nest or another smart thermostat which'll will help with costs as it'll know when we're out of the house or know our habits for keeping the place warm.

 

[UNG]

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful.

So how do you propose to install it then without creating an inefficient expensive to use heating system. The biggest issue with UFH are the losses into the slab / floor below it

Speaking to profressionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

So why come on here for advice and then go on to imply something that may offend those professionals on here, these profressionals you have spoken to are obviously up to speed with properties like yours and can offer a turnkey solution for you property. I have no doubt you could lay it on the current floor boards with a loss of room height but have they given any indication as to whether this compromises the efficiency of the system

 

[davesparks]

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful. Speaking to professionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

Professional what? Salesmen, installers or impartial third party engineers?
Have they quoted any actual figures for efficiency and heat losses for the different options?



You've got a lot of relatively impartial professionals on here advising you that you do need good insulation, so what makes your other professionals better than us?

 

[sean_ork]

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful. Speaking to professionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

I'm not sure what you currently do for a living, but I really do hope its nothing technical - your understanding of how insulation works is completely incorrect - perhaps you've been sold that nonsense by a salesman.

You could just lay insulation on top of your current FFL, but using your logic you'd not need any insulation, you'd just need to reflect it upwards.

Stop listening to sales folks, try talking to other who've actually got to live such a system - if you like throwing money away the carry on there Captain Mannering.

Your daughter won't be happy with just a few 100 watts of heated mat to keep her warm.


What's the EPC rating of the house ?

 

[sean_ork]

This idea of needing to dig down to china to make sure i have miles of insulation under the UFH just isn't required...I'm not needing to warm up the ground surface, I'm wanting the heat to be reflected upwards....the beauty of floating floor on top of ufh IS that it heats up quickly and cools down quickly imo.

Just out of curiosity, what have you read, or been told, that has made you form this opinion ?

 

[Midwest]

I think this thread is going round in circles. Seems we're back at the beginning again.

 

[sean_ork]

I think this thread is going round in circles. Seems we're back at the beginning again.

It's going backwards

 

[OnlyHumanHere]

It's going backwards

Agreed, so let's move forward.

My biggest issue still hasn't been resolved.

Let's ignore the pros and cons of UFH and whether it'll be worth it.

Let's say all of a sudden it is worth it and it's a great idea that'll be easy and simple.

My next concern is the boiler. Since I don't have space for a big tank in the garden for LPG, the cooker is LPG supplied via bottles stored on the side of the house..the bottles are only domestic, maybe about 19kg size.

How much and how long does it normally take to fit a combi boiler?

 

[UNG]

Firstly I'd like to thank everyone for their comments, it's been good to see insight from both sides of the fence.

Not sure what fence you are on about here

Having spoken with some specialists in Salsibury (though since we haven't got the keys yet, we haven't been able to get the some proper specialist advice)...I've told my wife to scrap the idea of putting ufh upstairs...since upstairs will be the guest room and my daughters room...there's no much need for the hassle....we'll just buy a heated play matt for our daughter it really matters. Like this but bigger (not sure why the photo is so big, apologies for that.

I am beginning to think this thread is the work of a troll as no one who is serious would consider one or more of these mats as an alternative to a properly designed and installed heating system, reading the spec alone worries me that you would even consider one or more of these mats for a child's room who will more than likely unsupervised most of the time, a surface temp of 40 - 60°C has the potential for burns or even causing a fire. I would have serious thoughts about your choice of specialist if they are recommending these mats

Like I said, there's no rush to move into the house, however I'm not a fan of tea breaks when a job needs doing so I expect things to be done in a timely manner. The beauty of being in the military is that I have a large supply of man power I can utilize for the price of a few crates of carling (they really aren't picky), which is nice.

I find some of your comments in this thread so far are very disparaging and insulting I think I'd prefer a tea drinking professional than a bunch of p****d up squaddies installing my heating system you what find out they are not too picky how good the finished system is

This idea of needing to dig down to china to make sure i have miles of insulation under the UFH just isn't required...I'm not needing to warm up the ground surface, I'm wanting the heat to be reflected upwards....the beauty of floating floor on top of ufh IS that it heats up quickly and cools down quickly imo. If the room is cold, I want it to heat up quickly, there's little draft in the house so there's no worry of heat escaping...there's not even a chimney in the house which is the main reason why old houses are normally drafty. I plan to kit the house out with google nest or another smart thermostat which'll will help with costs as it'll know when we're out of the house or know our habits for keeping the place warm.

I think you need to go and do some research about what insulation actually does. Once you have done that then you may want to research thermal effects and energy usage. Your comments show you have little knowledge on the subject and if you are relying on the specialists you have spoken to then you appear very very badly advised

I'm not sure what you currently do for a living, but I really do hope its nothing technical - your understanding of how insulation works is completely incorrect - perhaps you've been sold that nonsense by a salesman.

You could just lay insulation on top of your current FFL, but using your logic you'd not need any insulation, you'd just need to reflect it upwards.

Stop listening to sales folks, try talking to other who've actually got to live such a system - if you like throwing money away the carry on there Captain Mannering.

Your daughter won't be happy with just a few 100 watts of heated mat to keep her warm.


What's the EPC rating of the house ?

You are close although I think you may have the rank wrong

 

[davesparks]

Agreed, so let's move forward.

My biggest issue still hasn't been resolved.

Let's ignore the pros and cons of UFH and whether it'll be worth it.

Let's say all of a sudden it is worth it and it's a great idea that'll be easy and simple.

My next concern is the boiler. Since I don't have space for a big tank in the garden for LPG, the cooker is LPG supplied via bottles stored on the side of the house..the bottles are only domestic, maybe about 19kg size.

How much and how long does it normally take to fit a combi boiler?

Fitting the boiler itself takes maybe an hour, but then you have install all of the pipework to it, wire it, flush, fill, test, commission etc etc etc.

But if you can get a proper gas tank installed then you won't be wanting a gas boiler, you'll be changing bottles every other day!

 

[OnlyHumanHere]

Fitting the boiler itself takes maybe an hour, but then you have install all of the pipework to it, wire it, flush, fill, test, commission etc etc etc.

But if you can get a proper gas tank installed then you won't be wanting a gas boiler, you'll be changing bottles every other day!

Yea, I'm swaying to the idea of spending a bit of extra and getting a an electric boiler with indirect cylinder and scrapping the immersion heater.


I'm guessing that it shouldn't be too hard to replace the immersion heater since the piping will be in that area anyway.

I'm currently paying well over the odds in my current residence for gas and electric so no matter what I do I'll definitely be saving money.

 

[davesparks]

Electric Combis have come leaps and bounds in the last few years...

I'm guessing that it shouldn't be too hard to replace the immersion heater with a combi since most/all the piping will be in that area anyway.

Have they? What leaps and bounds would they be?

Guess again! The current hot water cylinder will be fed from a header tank above at low pressure with low pressure outgoing hot water. The combi will need a cold main and has a higher pressure hot water outlet, plus a relatively large electricity supply running to it.

 

[sean_ork]

Third time lucky maybe .......

What's the EPC rating of the house ?

 

[OnlyHumanHere]

Have they? What leaps and bounds would they be?

Guess again! The current hot water cylinder will be fed from a header tank above at low pressure with low pressure outgoing hot water. The combi will need a cold main and has a higher pressure hot water outlet, plus a relatively large electricity supply running to it.

ignore that comment, I'm an idiot. Just spoke to the electric heating company, they've recommended a comet 12kw boiler with 180L indirect cylinder.

looks like it'll do the job Indirect Cylinder Packages - The Electric Heating Company

 

[OnlyHumanHere]

without looking at the survey report I've no idea, apologies.

 

[telectrix]

that boiler will cost approx. £1.80 per hour running at 12kW. assuming it's on only 40% of the time ( which is optimistic in winter) that equates to about £120 per week.

 

[Midwest]

OP I don't know where your getting your briefing from about wet UFH. The concept, as far as I'm aware, is constant heating of the room temperature from the floor up, as opposed to the convection nature of wall hung rads. It not a quick heat up and cool down. The UFH pipes are installed to heat up the screed floor, to act as the heat source, which is not instant. The plastic pipes are not designed to heat the room themselves. Without insulation below the installed pipes, you will be doing exactly what say you don't want to happen, heat the ground below.

 

[sean_ork]

without looking at the survey report I've no idea, apologies.

I'm guessing this is the first house you've purchased ?

The EPC rating is a fairly vital piece of information, it should help guide you to where you need to spend money first.

Forget fancy remote control heating controls, forget electric boilers, forget those dangerous heat mats - spend your money on the fabric of the house first.

Please dig out your house buyers report and let us know its rating.

 

[davesparks]

that boiler will cost approx. £1.80 per hour running at 12kW. assuming it's on only 40% of the time ( which is optimistic in winter) that equates to about £120 per week.

But with a decent solid mass of screed around the ufh pipes and good insulation under them he'll get a pretty efficient system that only the water heated up to about 40 degrees......
.....
Oh no, wait a minute,
....
He's using magical heat reflecting snake oil! Forget that thought then.

 

[sean_ork]

ignore that comment, I'm an idiot. Just spoke to the electric heating company, they've recommended a comet 12kw boiler with 180L indirect cylinder.

looks like it'll do the job Indirect Cylinder Packages - The Electric Heating Company

What process did they use to calculate the energy requirement for your house ?

I'm guessing the wetfingerinair approach.

 

[davesparks]

What process did they use to calculate the energy requirement for your house ?

I'm guessing the wetfingerinair approach.

There are actually two really simple equations you can use for doing those calculations.
1: monthly sales target - units sold this month = boiler required
Or
2: what have we got an overstock of in the warehouse which needs shifting + know it all customer = kerching

 

[UNG]

I found this link quite interesting while I was looking at comparison costs of fuels used for domestic heating

 

[sean_ork]

I found this link quite interesting while I was looking at comparison costs of fuels used for domestic heating

Find a few links comparing the price of mains gas v LPG v electric and heating oil (sec28)

I'd bet he'll be wanting an oil boiler .....

 

[UNG]

We are up to page 6 of thread which parts haven't you understood so far, your specialist has told you that you don't need insulation and you came back with that typical military attitude telling us that we were all wrong

With your response I feel it is time this thread was closed as you seem to be having some / a lot of difficulty understanding what has been posted to date

Can I respectfully suggest that you take your research and questions somewhere else so that we don't have to waste our time and read your verbal diarrhoea