Unvented cylinder and boiler packages - W/B & Santon

[Bristolsteve]

Hi,

My normal work is mainly combis in small properties, and I only install Worcester boilers.

Ive got a large property who want a whole new install.

Ive calculated it will need 30kw on heating and 300l cylinder.

I wanted to know the best make cylinders as was going to install a Worcester 30cdi system boiler. I've been thinking of using a santon, are these reliable and compatable? I've noticed they do a pre plumb version, I take it I would not need the Worcester programmer with this option?

Thanks

 

[Destroyer2813]

I would use a 3ocdi system and a gledhill unvented, your still gonna need a timer with that pre plumb kit and dont they normally have a pump on em which you wont need if fitting a system boiler

 

[Bristolsteve]

I've just looked and the pre plumb kit does, it's on the inlet is there anything stopping me taking this out and using the one in the boiler?

 

[chris watkins]

Hi Bristolsteve
Have you got you Part G ticket (un-vented) ??
Potterton golds are cheap.

 

[Bristolsteve]

Yeah I have got my ticket, I service them sometimes but never put a new install in from scratch..

Im not worried about price as I'll just pass it on to customer, in their words 'we want quality and reliable over price within reason' was looking into megaflos but was told bubble can be problematic.

It looks like I can buy the boiler with integral diverter valve giving me separate flow and returns for cylinder and heating. And therefore can use a Worcester programmer..does this sound valid if I just brought the cylinder not pre plumbed?, all the safety and hot water controls like exp vessels and pressure reducing valve come with the cylinders don't they?

 

[Destroyer2813]

Steer clear of the internal stuff and controls told you need a degree to programme it, all your prv and bubbles come with the cylinders yes

 

[Roger Welton]

You will still need a two port to comply with regs for the unvented, the only way around that is with a viesmann boiler / cylinder comination as they have had them approved for use together without a 2 port.

Yes the cylinders come with regulator/expansion.

If cost isn't a problem i would be looking at the acv smartline cylinders.

 

[chris watkins]

Yeah I have got my ticket, I service them sometimes but never put a new install in from scratch..

Im not worried about price as I'll just pass it on to customer, in their words 'we want quality and reliable over price within reason' was looking into megaflos but was told bubble can be problematic.

It looks like I can buy the boiler with integral diverter valve giving me separate flow and returns for cylinder and heating. And therefore can use a Worcester programmer..does this sound valid if I just brought the cylinder not pre plumbed?, all the safety and hot water controls like exp vessels and pressure reducing valve come with the cylinders don't they?

Yep, all supplied, including a 2 port which IMO you should install in addition to the boiler diverter. Is there a secondary return on the hot water system ?? You can always add an expansion vessel to the Megaflo just in case.

 

[chris watkins]

You will still need a two port to comply with regs for the unvented, the only way around that is with a viesmann boiler / cylinder comination as they have had them approved for use together without a 2 port.

Yes the cylinders come with regulator/expansion.

If cost isn't a problem i would be looking at the acv smartline cylinders.

Interesting Roger they look similar idea to the MHS straitus(?) cylinders, where do you get these from & why do you recommend them?

 

[AWheating]

personally i would steer clear of the internal idea, much simpler/better to stick your 3/4/5 zone vavles either by the boiler or in the cylinder cupboard and use external controls.

 

[Roger Welton]

Interesting Roger they look similar idea to the MHS straitus(?) cylinders, where do you get these from & why do you recommend them?

Get them through my local merchants, I personally liker them as the reheat times and throughputs are very good the 210 will do a continous flow of over 15l min given suficient heat from the boiler! Also a nice solid piece of kit, the only thing you have to watch is that you presurise the domestic side 1st otherwise you can damage the shell

 

[Bristolsteve]

I think I'm going to go for standard system boiler, no integral filter, non pre plumbed cylinder, and buy a control pack, with all relevant controls included.

Does any one know if they're any good packs for what I need, and where you don't need to be a rocket scientist to set up and use?

Also re secondary circulation, as I understood it this is for having hot water quicker to the tap? Is it worth doing..I will be basically be working from stopcock up so new everything, should I be doing this particularly?

Thanks in advance...

 

[chris watkins]

I think I'm going to go for standard system boiler, no integral filter, non pre plumbed cylinder, and buy a control pack, with all relevant controls included.

Does any one know if they're any good packs for what I need, and where you don't need to be a rocket scientist to set up and use?

Also re secondary circulation, as I understood it this is for having hot water quicker to the tap? Is it worth doing..I will be basically be working from stopcock up so new everything, should I be doing this particularly?

Thanks in advance...

Steve don't buy a controls pack it will be a waste, all un-vented cylinder come with control & H/limit stats fitted & with a loose 2 port valve for the HW, you will need IMHO
2 x 2ports (one for upstairs heating & one for down stairs)
2 x room stats ( """")
1 x 3channel programmer
How big is the house how many beds / rads??? 30kW is a big you may find that the pump in the system boiler is not man enough for the system ??

Secondary is as you understand, it just depends how big the system is, a 300L suggest a very large house.

If this (installs) is not your normal line, as you say, you might do well to seek some professional design advise as they will have design indemnity insurance, it can be very easy the get things wrong on these larger systems nowadays, people wrongly think it is just the same a smaller houses. There is nothing wrong with getting the designs done, in fact the bigger clients may see it as well worth while to have some form of insurance if things go wrong.

 

[Bristolsteve]

Steve don't buy a controls pack it will be a waste, all un-vented cylinder come with control & H/limit stats fitted & with a loose 2 port valve for the HW, you will need IMHO
2 x 2ports (one for upstairs heating & one for down stairs)
2 x room stats ( """")
1 x 3channel programmer
How big is the house how many beds / rads??? 30kW is a big you may find that the pump in the system boiler is not man enough for the system ??

Secondary is as you understand, it just depends how big the system is, a 300L suggest a very large house.

If this (installs) is not your normal line, as you say, you might do well to seek some professional design advise as they will have design indemnity insurance, it can be very easy the get things wrong on these larger systems nowadays, people wrongly think it is just the same a smaller houses. There is nothing wrong with getting the designs done, in fact the bigger clients may see it as well worth while to have some form of insurance if things go wrong.

Thanks for the above.

The house is an old Edwardian stonewalled, high ceiling, detached 5 bed.

It will have 1 bath, 3 mixer showers

Do you think I've gone overkill on it? the heating requires just under 30kw..

Would a 42cdi cope with this or a hi flo?

Flow rate is 22 l/m

I thought unvented because there's 4 kids so thought they may get multiple use for hot water..

 

[chris watkins]

300L to big 210 or 250 max, 22l/m is not a lot, likely only two thing will be able to work at any time & whats the pressure like going up the building is it 3 stories ? Take a tip, get some one to help with the designs, nothing wrong in doing that.
Good luck
CW

 

[smhstu]

Hi all

I fit a lot of unvented systems. I fit Worcester Bosch 30 Cdi system boiler with internal diverter, Worcester TC 210 ( or whatever size required) Dt10RF Digistat
I link the twin coils up so recovery time is better. Also if in the future the customer wants to go down the solar thermal route they don't need a new cylinder.
The internal diverter means that you don't need any external zone valves.
Everything needed is supplied with the cylinder/internal diverter kit
Dead easy to fit and program, also all controls etc covered under there guarantee (currently five years longer if fitted by WAI) cylinder guaranteed 25 years
There pretty good on price too

Hope this helps

 

[smhstu]

I ment to say five year guarantee standard, longer if fitted by WAI

 

[fayraz]

Hi all

I fit a lot of unvented systems. I fit Worcester Bosch 30 Cdi system boiler with internal diverter, Worcester TC 210 ( or whatever size required) Dt10RF Digistat
I link the twin coils up so recovery time is better. Also if in the future the customer wants to go down the solar thermal route they don't need a new cylinder.
The internal diverter means that you don't need any external zone valves.
Everything needed is supplied with the cylinder/internal diverter kit
Dead easy to fit and program, also all controls etc covered under there guarantee (currently five years longer if fitted by WAI) cylinder guaranteed 25 years
There pretty good on price too

Hope this helps

I currently have a WB 30Cdi System with the internal diverter kit and do not have any external motorised valves on my system is this correct because some people have said you need motorised valves on also?