Boiler for large domestic premises

[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