Another boiler choice question

[AMEdinburgh]

It's another boiler selection posting, hoping for (helpful) comments

My extension will require more output than my ageing Worcester 350 combi can heat and I also wish to install a mains pressure hot water cylinger. We need up to a cubic metre of warm water for our hydro treadmill and therefore I hope to install a 500 twin coil tank., Initially the boiler would do the lower coil until I can finance a solar installation to take it's place, leaving the boiler on the upper coil

We need about 43KW and preferably a wall hanging boiler. Does this mean I'm beyond doemstic and into commercial products?

Any recommended models for value / reliability?

If it is a commercial boiler do I then need a commercial installer to install certify and service it or can any gas safe engineer do it?

Thanks in anticipation

 

[glasgowgas]

what is your total heat input in kws reqd

"domestic" htg eng can work up to 60 kw, 35mm pipe

you will have to include all gas appliances in your kw input (fires,cookers, etc etc) as your gas meter may have to be upped

 

[mickyg]

I would be tempted to work out properly the demands on the boiler. usually in a domestic property the HW requirements can be largely discounted as the cylinder may only need periodic heating which doesnt affect the CH.
Will the HW be in constant use? If so you may need to add 10kw+ to make sure you can quickly reheat the water whilst the heating is on. Have you properly calculated the CH demand? This should be a priority and quite simple to do a rough calculation(No. of Radiators X 1.5 = KW)
There isn't a great deal of choice of domestic boilers over 40kw, and you may even benefit from having 2 smaller boilers.
Anyway in the mean time here's some boiler porn that should fit your initial enquiry.
http://www.atagheating.co.uk/defaul...productgroepnaam=System boilers&productID=264

 

[AMEdinburgh]

Thank you, both of you.

The 43KW is the total heating requirement assuming everything's on including allowing 15KW for a heat exchanger for the hydro pool.

You are right about the pipe work. I've had an independant Gas Technical Services gentleman to look at our meter and current installation. The incoming pipework and meter is adequate for this new bigger boiler and also for a small one for the, soon to be constructed, roofspace flat, which will come off a secondary meter kiosk. However, he has specified 40mm to whatever boiler we choose and we're moving the new boiler position to near the meter, to minimise the run and extending the original 22mm boiler supply pipe (via a 25mm pipe to and from the secondary kiosk) upstairs to the new flat.

He mentioned, in passing, about commercial installers for the external pipework and presumable this is because of the 40mm pipe. Does that mean we can only use a commercial installer to fit and service such a boiler as the Atag mentioned because of the 40mm incoming pipe even though it's below 60KW.

 

[mickyg]

The pipework is commercial and will obviously require a commercial engineer to do any work on it. However, you can come off the main supply into 35mm or smaller pipework, fit an isolation valve and test tee and then a domestic chap can work from that point. Thats basically the work around.

 

[AMEdinburgh]

Thanks again, mickyg.

The Atag you mention is very compact which would be an advantage. Excluse my ignorance but in this type of boiler are the pumps in the boiler within the cabiney like my Worcester or outwith the boiler?

I had seen the Viessmann Vitodens 200W which in 45KW version has pumps addtional and below the case meaning it is nearly 1200mm tall.

 

[mickyg]

the pump is inside the case. btw if you go for this boiler I'd recommend contacting the manufacturer for an ATAG installer in your area.

btw it doesn't include an expansion vessel, but a module to go on the back of the boiler is available if space is limited.

 

[kirkgas]

what is your total heat input in kws reqd

"domestic" htg eng can work up to 60 kw, 35mm pipe

you will have to include all gas appliances in your kw input (fires,cookers, etc etc) as your gas meter may have to be upped

c'mon Glasgow you are showing your age, we can work on 70kw now

 

[AMEdinburgh]

Yes, as the website doesn't come up with anything for Edinburgh but I think that bit doesn't work for anywhere.

With a lower population density up here this is the point when the plan sometimes falters.

 

[mickyg]

Yes, as the website doesn't come up with anything for Edinburgh but I think that bit doesn't work for anywhere.

With a lower population density up here this is the point when the plan sometimes falters.

no it doesnt work, best to phone them.

 

[glasgowgas]

what is your total heat input in kws reqd

"domestic" htg eng can work up to 60 kw, 35mm pipe

you will have to include all gas appliances in your kw input (fires,cookers, etc etc) as your gas meter may have to be upped

c'mon Glasgow you are showing your age, we can work on 70kw now

apologies Kirkie, post was a bit rushed

 

[AMEdinburgh]

Whilst awaiting Atag, are there any others I should consider?

In terms of runnung the pipes from the boiler, to the calorifier, is it generally better to have them below the floor or above the boiler height (in the void between the suspended ceiling and the true ceiling). Either is possible, with some enablng works.

What's the thoughts on plastic pipework once far enough from the boiler. It would mean no chance of leaking and be considerably easier to pass between the rooms to the tank?

Thank you.

 

[glasgowgas]

you could have a look at a Vaillant they do a light commercial one (42kw) system boiler, or remeha quinta 45kw

 

[AMEdinburgh]

Thank you Glasgowgas. Now have four to choose from and which might open up more installer possiblities. Is there a reliability preference and are you are of anyone on this end of the M8 or is it not permitted to recommend installers.

 

[glasgowgas]

not really sure of any Embra posters

as for reliability, never seen an Atag or a Viesmann

plenty of Quinta`s about