Complete New Boiler installation Set Up

37
Found 8th Aug
I’m currently extending and renovating a property I’ll
hopefully be moving into soon.



It’s an old 1930’s 3 bed (will be 5) and currently has an
old Baxi back boiler, a few Rads in some rooms.



The idea is to gut everything and fit a new system boiler in
from scratch. I’ve had someone in who’s an approved Worcester Bosch installer
and we have agreed for him to do the job on a labour only basis. So I’ll be
buying ALL the bits…



Just wondering if anyone can give me any advice on a good
set up for a 5 bed house. I’ve got a bit of a shopping list off the installer.
I know I’m getting the WB system 35CDI and I’d like to get a Nest 3rd
Gen to go with it.



In terms of unvented tanks, port valves, radiators and any
other bits and bobs – I have no idea.



Can anyone advise of what would be an ideal set up? What brands
should I be looking at? Is it worth having an electric immersion heater fitted
in at the same time as back- up?



Thanks in advance
Community Updates
Ask
Top comments
pay your installer a little extra and get them to do it all. removing a back boiler is a big job. it just isn't worth the hassle of conflicting advice from Internet strangers on an expensive and big job.
Edited by: "discozohan" 8th Aug
37 Comments
pay your installer a little extra and get them to do it all. removing a back boiler is a big job. it just isn't worth the hassle of conflicting advice from Internet strangers on an expensive and big job.
Edited by: "discozohan" 8th Aug
You will definitely want the Immersion wired up, it's already fitted to the cylinder...

That is a massive boiler for even a 5 bed house.

If it's a house you want to stay in for a long time get everything piped in copper, and make sure the rads are piped in 15mm.

Honeywell zone valves, Danfoss TRVs. If it were me I'd spec a properly sized Intergas boiler (Opentherm can be used with the Nest!), and a Joules cylinder. If you have a big budget get an ACV cylinder.
discozohan14 m ago

pay your installer a little extra and get them to do it all. an electric …pay your installer a little extra and get them to do it all. an electric immersion isn't worth it for the once every 10 years it may go wrong. removing a back boiler is a big job. it just isn't worth the hassle of conflicting advice from Internet strangers on an expensive and big job.


Agree, will you pay for his time when you’ve supplied wrong or missing parts? Do you get trade prices, and hassle free returns like a tradesman?
Will the installer turn around if there’s a fault down the line and say it’s down to your choice of components?
Good work isn’t cheap, and cheap work isn’t good
Have you done a heat loss calculation to spec that boiler?
themorgatron20 m ago

You will definitely want the Immersion wired up, it's already fitted to …You will definitely want the Immersion wired up, it's already fitted to the cylinder...That is a massive boiler for even a 5 bed house.If it's a house you want to stay in for a long time get everything piped in copper, and make sure the rads are piped in 15mm.Honeywell zone valves, Danfoss TRVs. If it were me I'd spec a properly sized Intergas boiler (Opentherm can be used with the Nest!), and a Joules cylinder. If you have a big budget get an ACV cylinder.


themorgatron always offers good advice.

You definately want the imersion installed and wired - like an insurance policy you hope you never need to use it but gives you assurance for the occasional day that your boiler (or pump or valve actuator) is out of service.

I like the Myson Premier radiator - simple straight forward look with a round top. I find them normally competitively priced here... directheatingsupplies.co.uk/mys…ors
discozohan58 m ago

pay your installer a little extra and get them to do it all. removing a …pay your installer a little extra and get them to do it all. removing a back boiler is a big job. it just isn't worth the hassle of conflicting advice from Internet strangers on an expensive and big job.


Yes, im going to do that.
themorgatron49 m ago

You will definitely want the Immersion wired up, it's already fitted to …You will definitely want the Immersion wired up, it's already fitted to the cylinder...That is a massive boiler for even a 5 bed house.If it's a house you want to stay in for a long time get everything piped in copper, and make sure the rads are piped in 15mm.Honeywell zone valves, Danfoss TRVs. If it were me I'd spec a properly sized Intergas boiler (Opentherm can be used with the Nest!), and a Joules cylinder. If you have a big budget get an ACV cylinder.



My installer did spec the 30CDI, but having looked at the prices, the 35CDI worked out to £100 more. I figured i might as well future proof myself for the bit extra.

Thanks for the other recommendations. I'll take a look..
moneybag53 m ago

Agree, will you pay for his time when you’ve supplied wrong or missing p …Agree, will you pay for his time when you’ve supplied wrong or missing parts? Do you get trade prices, and hassle free returns like a tradesman?Will the installer turn around if there’s a fault down the line and say it’s down to your choice of components?Good work isn’t cheap, and cheap work isn’t good


I'll obviously give my installer a list and make sure he's happy with what I am buying. My installer has already said to me he doesn't really get much off in terms of trade price off the boiler anyway. Maybe the other bits he does - I'll get a list together and see if he can improve on the prices.
Edited by: "king132" 8th Aug
discozohan1 h, 9 m ago

pay your installer a little extra and get them to do it all. removing a …pay your installer a little extra and get them to do it all. removing a back boiler is a big job. it just isn't worth the hassle of conflicting advice from Internet strangers on an expensive and big job.


This. If he’s an approved installer, he should be able to get a fair deal. Always goes wrong when customer buys the bits. If there’s stuff missing, he will be within his rights to charge you money for going to get them etc. As others have said, I wouldn’t guarantee parts bought by the customer either.
Honestly the plumber is going to be annoyed with the extra work babysitting your buying and speccing. So there is a good chance they'll add a premium ontop and increased chance they'll drop out before the work begins.

Really with stuff like this it's much much better to get them to do the buying and fitting.
They'll be buying for multiple jobs at once, get trade discounts and know exactly that to get.
A year down the line if a piece of the hardware breaks you go directly back to one source. If your buying it then they'll blame the part you supplied. You'll have to chance the seller then the plumber to get the replacement fitted.
If you want to supply parts just buy the 'big ticket' items, leave the rest to him. Some like this arrangement as it keeps them under the VAT threshold. You're also not then left with a half opened bag of fittings, 3/4 of a roll of solder, 200 assorted clips etc.

There's no such thing as trade prices, or trade discount. There's the price the merchant charges tradesman, then the cheaper online price available to all.
king13226 m ago

My installer did spec the 30CDI, but having looked at the prices, the …My installer did spec the 30CDI, but having looked at the prices, the 35CDI worked out to £100 more. I figured i might as well future proof myself for the bit extra.Thanks for the other recommendations. I'll take a look..


That’s not how boilers work, if you buy too big then you’ll waste gas as it won’t be able to modulate down as much and will be less economical.
Don't know the size of your property, how many bathrooms etc but I have a 3 bed semi 1 bathroom and have a Vaillant 31 kw combi (a wee bit more than needed but better to have something running below capacity) . I suppose with a system boiler (you'll have a hot water tank ) the rating (kwh ) is not so important as with a combi boiler as a system boiler does not have to produce instant hot water to possibly 2 or three hot taps/showers .

Disagree with a previous comment - unless you are way over the required capacity (in kwh) the boiler will obviously operate more efficiently at 60% capacity than 100% capacity. Just look at it sensibly - any boiler will be just ticking over 90% of the time (for the hot water in summer or hot water and a little heating in Autumn) so I think you can disregard that comment . You want one that can deal comfortably with all the rads in the depths of winter without flogging itself to death .

I suggest your installer knows better than the (not too well informed comment ) from a previous commenter .
Main things to think about when calculating size.

Do you have showers that run off a tap(I.e. not electric shower)?

How many radiators and how big they are.
cmdr_elito5 m ago

Main things to think about when calculating size.Do you have showers that …Main things to think about when calculating size.Do you have showers that run off a tap(I.e. not electric shower)?How many radiators and how big they are.



Remember its a "system boiler " - not a combi , so hot taps don't come into the equation .
rogparki4 m ago

Remember its a "system boiler " - not a combi , so hot taps don't come …Remember its a "system boiler " - not a combi , so hot taps don't come into the equation .


Oh yes, I wouldn’t install anything other than a combi. It wastes too much space and is only minimally more efficient in larger houses.
cmdr_elito8 m ago

Oh yes, I wouldn’t install anything other than a combi. It wastes too much …Oh yes, I wouldn’t install anything other than a combi. It wastes too much space and is only minimally more efficient in larger houses.



Would agree , best thing I ever did ,getting a combi fitted. Pretty sure its a lot more efficient .at least for a 3 Bed house with one occupant ,one bathroom , and comforting as no header tanks in the loft (had a leak that brought a ceiling down a few years back ! ).
rogparki15 m ago

and comforting as no header tanks in the loft (had a leak that brought a …and comforting as no header tanks in the loft (had a leak that brought a ceiling down a few years back ! ).


That statement just shows me much you know about plumbing and heating, have you heard of an unvented water cylinder?.
Edited by: "paulj48" 8th Aug
rogparki15 m ago

Would agree , best thing I ever did ,getting a combi fitted. Pretty sure …Would agree , best thing I ever did ,getting a combi fitted. Pretty sure its a lot more efficient .at least for a 3 Bed house with one occupant ,one bathroom , and comforting as no header tanks in the loft (had a leak that brought a ceiling down a few years back ! ).


For smaller houses it’s far more efficient to have a combi, for larger fully occupied houses the tank system is more efficient.
paulj4822 m ago

That statement just shows me much you know about plumbing and heating, …That statement just shows me much you know about plumbing and heating, have you heard of an unvented water cylinder?.



That's a "system" set up as opposed to a combi set up - tell me how a boiler operating below capacity is so inefficient ? Lets face it any boiler is operating well below capacity for 90% of the time , especially a system boiler which in summer is just topping up the heat in the "unvented hot water cylinder" probably running for 6 months at least at 2% - 5% capacity .

So according to you the boiler is unable to "modulate " (whatever that means !) down to that - so is grossly inefficient for probably 9 months of the year , whatever its output .

Hope your second day at plumbing school goes better
rogparki8th Aug

That's a "system" set up as opposed to a combi set up - tell me how a …That's a "system" set up as opposed to a combi set up - tell me how a boiler operating below capacity is so inefficient ? Lets face it any boiler is operating well below capacity for 90% of the time , especially a system boiler which in summer is just topping up the heat in the "unvented hot water cylinder" probably running for 6 months at least at 2% - 5% capacity .So according to you the boiler is unable to "modulate " (whatever that means !) down to that - so is grossly inefficient for probably 9 months of the year , whatever its output .Hope your second day at plumbing school goes better



Its basic physics but I'm not going to waste my time explaining it to you, now wheres that ignore button.
Thanks for all your replies. I'm going to heed advice on here and let the installer buy the parts he's going to need and maybe just look at seeing if i can get the higher price items cheaper online myself.

I'll stick with the WB 35CDI System boiler though as i'll get a 7-10 year warranty through the installer. Looking at around 15 odd radiators (10 large and 5 small to medium) and two bathrooms both will have mixer tap showers and one will have the bath also.
king13210 m ago

Looking at around 15 odd radiators (10 large and 5 small to medium) and …Looking at around 15 odd radiators (10 large and 5 small to medium) and two bathrooms both will have mixer tap showers and one will have the bath also.


Are these existing radiators or new and how did you spec the size? Did you or your plumber do a heat loss calculation or just guessing?
paulj486 m ago

Are these existing radiators or new and how did you spec the size? Did you …Are these existing radiators or new and how did you spec the size? Did you or your plumber do a heat loss calculation or just guessing?


All new and no i havent done a heat loss calculation - i've just looked at where we will have wall space and the size of each room and just estimated what size radiator would be suitable.
king13235 m ago

All new and no i havent done a heat loss calculation - i've just looked at …All new and no i havent done a heat loss calculation - i've just looked at where we will have wall space and the size of each room and just estimated what size radiator would be suitable.


Wow, wonders never cease. Hope you’ve not ‘estimated’ any load bearing wall changes in your renevation.

Have you applied for planning permission (if applicable) and submitted to building control? Did they not want to see plans and figures so you comply?.
paulj481 h, 47 m ago

Wow, wonders never cease. Hope you’ve not ‘estimated’ any load bearing wall …Wow, wonders never cease. Hope you’ve not ‘estimated’ any load bearing wall changes in your renevation.Have you applied for planning permission (if applicable) and submitted to building control? Did they not want to see plans and figures so you comply?.


The number of radiators and locations of them, what boiler you have has nothing to do with BC?
king1324 m ago

The number of radiators and locations of them, what boiler you have has …The number of radiators and locations of them, what boiler you have has nothing to do with BC?



I'm not an architect but don't you have to comply with part L now?
Take a look at Valiant, my installer recommended it as he is a recommended installer and it comes with a 7 year parts and labour guarantee, for the rads I would just go for Screwfix ones (Kudox brand)
All decent installers will get the stock at a decent price and delivered for the day of installation.

Are you sure about your installer, might be worth checking Checkatrade to get another couple of quotes.
Edited by: "davewave" 9th Aug
davewave9 m ago

Take a look at Valiant, my installer recommended it as he is a recommended …Take a look at Valiant, my installer recommended it as he is a recommended installer and it comes with a 7 year parts and labour guarantee, for the rads I would just go for Screwfix ones (Kudox brand)All decent installers will get the stock at a decent price and delivered for the day of installation.Are you sure about your installer, might be worth checking Checkatrade to get another couple of quotes.


Intergas come with a 10 year warranty out of the box
You’d put a combi in a 4/5 bed house with 2/3 bathrooms?

Unvented any day for me. No issues with uneven pressures, can run taps at the same time as showering without scalding etc.

An unvented system doesn’t have a tank, it’ll just be a cylinder and boiler. I’d advise looking roughly at your radiator sizes, look at the kw capacity of each on and add them up, then add a percentage on for any extra for the future. A 26kw system boiler should suit most mid size houses. Then sizing a cylinder which will obviously be indirect (heated by boiler), but you’ll want an immersion too. Will you be running many hot taps/outlets at the same time or for long periods? Have a browse on Gledhill website and it can give a rough guide on size. 180-210L would normally be sufficient for what you’re after.
Edited by: "MattNorfolk" 9th Aug
paulj481 h, 22 m ago

Intergas come with a 10 year warranty out of the box


Is that for labour as well as parts?
davewave32 m ago

Is that for labour as well as parts?


Yes.
paulj4811 m ago

Yes.


Wow, thats excellent.

intergasheating.co.uk/con…ut/

They seem good according to Which scores...I guess if you can find a plumber who has installed them before then a 10 yr parts and labour would be amazing!!!!
davewave9th Aug

Wow, thats excellent.https://www.intergasheating.co.uk/consumer/about/They …Wow, thats excellent.https://www.intergasheating.co.uk/consumer/about/They seem good according to Which scores...I guess if you can find a plumber who has installed them before then a 10 yr parts and labour would be amazing!!!!


There’s no stipulation that a plumber has to have fitted one before for the 10 year warranty to be valid.

Apparently they are very easy to fit and any Gas Safe plumber should have no issues fitting it
paulj488 m ago

There’s no stipulation that a plumber has to have fitted one before for t …There’s no stipulation that a plumber has to have fitted one before for the 10 year warranty to be valid. Apparently they are very easy to fit and any Gas Safe plumber should have no issues fitting it


I think it might be 12 year not 10 year

Link to fitter

Ever since CEO David Smith first formed 50five, we have exclusively installed only Vaillant boilers due to their unmatched quality and reliability.

It is however then no small feat that another boiler manufacturer by the name of lntergas has impressed us enough for us to install their boilers. Not only do Intergas boilers have only 4 moving parts, increasing both reliability and efficiency, but they are also fitted with revolutionary technology, which allows the heating installer to monitor the boiler after fitment meaning that any potential faults can be detected before they become a problem.

Intergas boilers also come lnTouch App ready, this clever little app allows you to control and monitor your boiler via your smartphone or tablet wherever you are in the world as long as you have an internet connection! However InTouch doesn't just provide the convenience of fingertip control, it can boost the efficiency of the ECO RF boiler still further. This is because it works with the Honeywell Round OpenTherm room thermostat, which communicates more effectively with the boiler, so the boiler uses less energy when it responds to varying demand.

Due to the high install quality we maintain, lntergas were happy to allow us to offer an unmatched, industry leading 12 Year Parts and Labour Manufacturer's Warranty. This warranty is testament to lntergas' confidence in their products and our ability to install the boiler to the highest possible standards, which include a full system chemical flush, treatment with ADEY Chemicals, the installation of an ADEY MagnaClean Micro 2 Filter and a full water test.
davewave17 m ago

I think it might be 12 year not 10 yearLink to fitterEver since CEO David …I think it might be 12 year not 10 yearLink to fitterEver since CEO David Smith first formed 50five, we have exclusively installed only Vaillant boilers due to their unmatched quality and reliability.It is however then no small feat that another boiler manufacturer by the name of lntergas has impressed us enough for us to install their boilers. Not only do Intergas boilers have only 4 moving parts, increasing both reliability and efficiency, but they are also fitted with revolutionary technology, which allows the heating installer to monitor the boiler after fitment meaning that any potential faults can be detected before they become a problem.[Image] Intergas boilers also come lnTouch App ready, this clever little app allows you to control and monitor your boiler via your smartphone or tablet wherever you are in the world as long as you have an internet connection! However InTouch doesn't just provide the convenience of fingertip control, it can boost the efficiency of the ECO RF boiler still further. This is because it works with the Honeywell Round OpenTherm room thermostat, which communicates more effectively with the boiler, so the boiler uses less energy when it responds to varying demand.Due to the high install quality we maintain, lntergas were happy to allow us to offer an unmatched, industry leading 12 Year Parts and Labour Manufacturer's Warranty. This warranty is testament to lntergas' confidence in their products and our ability to install the boiler to the highest possible standards, which include a full system chemical flush, treatment with ADEY Chemicals, the installation of an ADEY MagnaClean Micro 2 Filter and a full water test.


I had an ECO RF fitted in April this year, my warranty letter from Intergas (after registration) states 10 years.

Dont get confused between a manufacturers warranty and a warranty offered by an plumbing/installation company.

Sime installation companies give 15 year warranties but charge over the odds for the initial job and the required services to cover any eventuality
Edited by: "paulj48" 9th Aug
paulj4830 m ago

I had an ECO RF fitted in April this year, my warranty letter from …I had an ECO RF fitted in April this year, my warranty letter from Intergas (after registration) states 10 years.Dont get confused between a manufacturers warranty and a warranty offered by an plumbing/installation company.Sime installation companies give 15 year warranties but charge over the odds for the initial job and the required services to cover any eventuality


fair enough, makes sense.
Post a comment
Avatar
@
    Text

    Top Discussions