Boiler for large domestic premises

[GQuigley67]

Went to price job today, current boiler 55kw, customer wants a single large output boiler and was already quoted for 2 domestic boilers linked together which he didn't sound too keen on. His current setup is Ideal Concord C 55kw for heating and a separate water heater for 300L unvented with no efficient controls of the system, and due to the size of property very large gas bills.

All the boilers above 40kw all seem to be classed as commercial by the manufacturer so even though it's below 70kw falls under commercial. U16 meter in property total pipe size without measuring is probably below 0.035m3(total guess but max pipe 35mm)

What qualications would I need as a minimum to do this installation? Or is there any domestic classed larger boilers anyone knows of? (I can't find any anywhere) I had a quick look online but there are so many commercial qualifications it's unreal. I can'tell see me getting into the commercial side here as it will all be tied up by the big boys, but for certain installation types like this it may come in handy if not too expensive

 

[ShaunCorbs]

i may be wrong but didnt gas safe say aslong as your output and m3/h is below the commercial your ok

(croppie to confirm as im sure hes the one that posted something like that )

and worcester 162 60kw

 

[GQuigley67]

Already spoke to gas safe if it's classed as commercial then nope even below 70kw

 

[ShaunCorbs]

fair enough tbh best way for you is any commercial guys locally that can give you a hand for a day or two?

if not you need i would say

CoDNC1
TPCP1/A
ICPN1
CIGA1

 

[GQuigley67]

yes probably best just going down that route, thanks.

 

[Dotty]

Speak to WB. I'm pretty sure that they classify the GB162/60 as a large domestic.

 

[mfgs]

As soon as the manufacturer describes it as commercial or refers to any commercial regulation in the MI's then you need your commercial ticket regardless of if it is below 70kw.
I would love to do my commercial gas but I have zero experience and don't want to go into it completely blind.

 

[GQuigley67]

Checked the commissioning on the WB and it was commercial and it's under their commercial products. Will just have to find a commercial guy.

 

[GQuigley67]

spoke with worcester they say I can fit the 65kw boiler even though they class it as commercial although the commissioning procedure seems different to your normal domestic boiler.

 

[ShaunCorbs]

spoke with worcester they say I can fit the 65kw boiler even though they class it as commercial although the commissioning procedure seems different to your normal domestic boiler.

Double check with gas safe and your golden then

 

[GQuigley67]

Well it's below 60kw and Worcester even offer to commission it for you for a price so happy days. MI always override I'm sure.

Gas safe was pretty much sayin check with manufacturer. Hope I win job now will be a challenge haha.

 

[mutley racers]

spoke with worcester they say I can fit the 65kw boiler even though they class it as commercial although the commissioning procedure seems different to your normal domestic boiler.

No way, if this is true I just missed out on some nice installs. So Worcester say you can fit a 60kw boiler classed as commercial? Are you allowed to commission it?

 

[mutley racers]

Speak to WB. I'm pretty sure that they classify the GB162/60 as a large domestic.

It does say large domestic or commercial but in the commercial section. Tricky

 

[Dotty]

Go on, you can all say it......


Croppie's right.......

 

[ShaunCorbs]

Go on, you can all say it......


Croppie's right.......

partly as its still listed on there instructions as commercial 😀

have one lucky charm

 

[GQuigley67]

No way, if this is true I just missed out on some nice installs. So Worcester say you can fit a 60kw boiler classed as commercial? Are you allowed to commission it?

Yes you are but if your not too confident you can pay them £200+VAT to do so. The models below 80kw come with a free converter to convert the electrics to accommodate domestic controls.

 

[mutley racers]

Yes you are but if your not too confident you can pay them £200+VAT to do so. The models below 80kw come with a free converter to convert the electrics to accommodate domestic controls.

That's really good information to know. Thank you

 

[GQuigley67]

Found worcester sales team very helpful

 

[mutley racers]

Found worcester sales team very helpful

Sales team, scary.

 

[GQuigley67]

It was technical department I was speaking to but obviously for products your going to install not existing

 

[mutley racers]

It was technical department I was speaking to but obviously for products your going to install not existing

Good to hear

 

[GQuigley67]

The saga continues...

Spoke to gas safe regarding and they say as far as they are concerned if it's classed as a commercial boiler it's a commercial ticket, so then phoned worcester again (spoke to 3 different ppl there now regarding this) and he's sayin yes as it's classed as domestic under 70kW so he gave me an email address and I'm trying to get this in writing from Worcester.

Gas safe advised me to get it in writing to cover myself, said the manufacturer should make it more clear that it's domestic, and agrend their instructions override gas safe.

 

[mutley racers]

The saga continues...

Spoke to gas safe regarding and they say as far as they are concerned if it's classed as a commercial boiler it's a commercial ticket, so then phoned worcester again (spoke to 3 different ppl there now regarding this) and he's sayin yes as it's classed as domestic under 70kW so he gave me an email address and I'm trying to get this in writing from Worcester.

Gas safe advised me to get it in writing to cover myself, said the manufacturer should make it more clear that it's domestic, and agrend their instructions override gas safe.

No way. How confusing is that hey. Still we all know MI's overall. Thanks for keeping us updated and please continue to do so

 

[GQuigley67]

Well they've confirmed it in writing, think I'm just gonna quote for the 80kw anyway keep customer happy and get guy in to commission the boiler, customer has heart set on the 80kw for whatever reason thinks he knows best.

 

[mutley racers]

Well they've confirmed it in writing, think I'm just gonna quote for the 80kw anyway keep customer happy and get guy in to commission the boiler, customer has heart set on the 80kw for whatever reason thinks he knows best.

So, you are allowed to install a 80kw boiler even though your ticket is upto 70kw?

 

[ShaunCorbs]

So, you are allowed to install a 80kw boiler even though your ticket is upto 70kw?

No he's going to get a commercial guy to sign and commission it

 

[mutley racers]

No he's going to get a commercial guy to sign and commission it

From Worcester for £240. Not bad. What if you link two, will they charge double

 

[Scott_D]

Could you forward me the confirmation email please?

 

[kozak1968]

The Gas safe TB053 might help.

 

[GQuigley67]

I'll be getting a commercial guy to do gas side of boiler, nothing stopping me doing hydraulic side. I will post the conversation between me and technical when I get the chance. They have confirmed.it will work on a domestic S Plan, just need to find large 2 port valves lol

 

[ShaunCorbs]

I'll be getting a commercial guy to do gas side of boiler, nothing stopping me doing hydraulic side. I will post the conversation between me and technical when I get the chance. They have confirmed.it will work on a domestic S Plan, just need to find large 2 port valves lol

What size? Also look at amz valves and actuators

 

[GQuigley67]

About 1 "1/2 at least, i seen some online a while back around £150. just gave an estimate for the job if they accept will do a more detailed surveyou.

 

[mutley racers]

So chaps my van decided to pack up today so at home now doing some estimates. Looking g through the gb162 brochure and found this...

 

[Fowlersrs]

This is correct. There is so much confusion surrounding commercial gas it's untrue. I had a similar question and the following facts apply.

Firstly as long as the boiler is under 70kw ie not a commercial boiler then you can install it, note worcester product you are looking at is a domestic boiler but a large one and is based on commercial design so that's where people can get some confusion. I'm pretty sure also that worcester insist on putting anything above a certain size (I think it's 40kw but don't quote me on it) into a low loss header so as the boiler can keep up with demand.

The next and most crucial part. The definition of commercial gas work is NOT defined by the property type. I see sooooo many people assume this.

It is deemed by the supply size your working on at this property. If the volume of gas installation pipework exceeds 0.35m3 then you must hold commercial acs tickets...

So what I would say to you is when you survey the work you look at the present installation of gas pipework and work out volume. Is it correctly sized for new appliance? If not what size will it have to be and what will the new volume be. If it's getting pretty close to 0.35m3 I wouldn't take the chance.

I got a lot of conflicting info on this but got there in the end. It is definitely down to gas pipework volume and not the property.

 

[Scott_D]

Vaillant sent out an email recently about their 46 and 65 kW boilers being "domestic"

 

[mutley racers]

Firstly as long as the boiler is under 70kw ie not a commercial boiler then you can install it, note worcester product you are looking at is a domestic boiler but a large one and is based on commercial design so that's where people can get some confusion. I'm pretty sure also that worcester insist on putting anything above a certain size (I think it's 40kw but don't quote me on it) into a low loss header so as the boiler can keep up with demand.

The 50 and 65kw one's don't. Only if you use the RC35 control

 

[mutley racers]

But apparently cascading 2 50 kw boilers takes it into commercial

 

[ShaunCorbs]

But apparently cascading 2 50 kw boilers takes it into commercial View attachment 26452

single boiler upto 70kw or any cascade under 70kw eg 2x 35kw, 3x 20kw etc

 

[Fowlersrs]

Well yeah it will 100kw installation. I can see what your saying though.. What u need to remember is headers lend themselves well to multiple zones with high demand as u can separate out pumps. Instead of relying on the flow rate of one pump to do 20-30 rads

 

[mutley racers]

single boiler upto 70kw or any cascade under 70kw eg 2x 35kw, 3x 20kw etc

Oh I see. I thought you could install as many 35 kw boilers cascade as you like. Glad I never had the chance to mess that one up

 

[mutley racers]

Can anyone tell me if you measure the heat input of a room differently (height) if using de stratification fans. Hard to find any info on it

 

[Tjdservices]

Sorry to jump on the bandwagon but I have been asked to price up a huge house. It has 2 gas meters as one supplied the house and the other was for the original swimming pool heating, the are both u6 meters. I thought it was commercial but he has had quotes from other companies fitting 2 boilers in series for the hot water and ufh on the 1st floor from 1 meter and then a second boiler 50kw for the ground floor heating off the 2nd meter. I can't find anything that says this is either ok or not and Gassafe are there usual vague selves. Worcester who have specified the boilers seem to think it is fine on a domestic ticket as the volume and kW is under the requirements for each meter and the 2systems in the house will be independent from each other. It would be a great job but I'm sceptical. Any advice, appreciated

 

[ShaunCorbs]

Sorry to jump on the bandwagon but I have been asked to price up a huge house. It has 2 gas meters as one supplied the house and the other was for the original swimming pool heating, the are both u6 meters. I thought it was commercial but he has had quotes from other companies fitting 2 boilers in series for the hot water and ufh on the 1st floor from 1 meter and then a second boiler 50kw for the ground floor heating off the 2nd meter. I can't find anything that says this is either ok or not and Gassafe are there usual vague selves. Worcester who have specified the boilers seem to think it is fine on a domestic ticket as the volume and kW is under the requirements for each meter and the 2systems in the house will be independent from each other. It would be a great job but I'm sceptical. Any advice, appreciated

think you mean u16?????

 

[Masood]

single boiler upto 70kw or any cascade under 70kw eg 2x 35kw, 3x 20kw etc

Not only boilers - ALL gas appliances totalled up. If you have a 65KW boiler, and a 7KW hob, you're outside domestic scope.

 

[Tjdservices]

think you mean u16?????

No the property has 2
Separate u6 meters.

 

[Tjdservices]

Not only boilers - ALL gas appliances totalled up. If you have a 65KW boiler, and a 7KW hob, you're outside domestic scope.

only other gas requirement is 6kw for the aga, this is included in the proposed set up for the 50kw boiler downstairs.which is 1 50kw boiler and the the aga so 56kw, off of meter one then 2 X 30kw on the first floor from meter 2.

It doesn't feel right to me. My initial thoughts were supply and meter upgraded to u16 then have the heat requirements for the whole house calculated and the gas side completed by a commercial engineer. But then with a quite from a domestic guy stating the above I don't want to lose out on a job of this size of it does fall within my domestic scope. And yes if it doesn't feel right I probably should go with my gut.

 

[Atouchofgas]

How far are the boilers to the meter? The 50 will need at least 35mm and depending on the run will take it to commercial ditto for the 2 30s

 

[Tjdservices]

How far are the boilers to the meter? The 50 will need at least 35mm and depending on the run will take it to commercial ditto for the 2 30s

I'm visiting the site on Monday to do a survey, so will get the distances and spec then, I think that your right and the gas capacity will be the issue.

 

[Tjdservices]

Will update on Monday.

 

[Tjdservices]

Right, been to have a look and this is what people are quoting for. the 1st meter will require a 9m run including fittings. This is for the 2 boilers in series (Worcester 27 system), these 2 boilers will heat the ufh on the 1st floor and the hot water cylinders.

The second gas meter has a run of 6m inc fittings. This is serving the aga 6kw, and then 2 Worcester 27 systems in series to heat the ground floor radiators.

Is this actually possible, I can't get a straight answer and don't really want to quote, start and then find out I can't sign it off. I'm leaning more towards leVing it as it does seem odd with 2 meters even though the 1st floor and ground floor are separate systems. Any thoughts or help with the regs interpretations would be very helpful.

 

[GQuigley67]

So little update, I've now installed 2 of the GB162 commercial boilers, and in the brochure it clearly states the 50/65kw models can be installed by domestic engineers.

80kw in a domestic house on S-Plan system
It's worth noting that the 42mm 2 port required its own power supply


50kw (not finished)

 

[ShaunCorbs]

What size gas meter ?

 

[GQuigley67]

Don't worry it's a U16

 

[ShaunCorbs]

Don't worry it's a U16

😀 track pipe also ?

 

[kozak1968]

I understood the maximum size was 70kw total, whether you fit 1, 2, 3 boilers etc.

 

[GQuigley67]

Yes but wasn't sure if the ones upto 70kw were allowed to fit as they were described as commercial, so had conflicting advice from gas safe, but Worcester confirmed that the smaller models are OK for domestic engineers even though they are branded commercial. Commercial gas guy done the gas side for the 80kw(our very own atouchofgas)

The one with tracpipe is a u6 meter as its only 50kw

 

[ShaunCorbs]

Yes but wasn't sure if the ones upto 70kw were allowed to fit as they were described as commercial, so had conflicting advice from gas safe, but Worcester confirmed that the smaller models are OK for domestic engineers even though they are branded commercial. Commercial gas guy done the gas side for the 80kw(our very own atouchofgas)

The one with tracpipe is a u6 meter as its only 50kw

How did you find commissioning ??

 

[Atouchofgas]

Easy enough

 

[ShaunCorbs]

They are and nice easy money