Can I use a standard/'heat only' boiler instead of a system boiler?

[CZFred]

Hi - my first post here, so apologies if I'm breaking any protocols!


I am fitting an entire new system, 5 beds, 3 floors, 2 bathrooms. It will be an unvented indirect cylinder/tank, a boiler and a potable water expansion vessel.

The boiler in such a setup would normally be a system boiler. But can I choose to use a standard boiler instead, as long as I have a pump and a second (hot water) expansion vessel in my system, i.e. to replace the components that a system boiler has inside the box, and that a standard boiler does not?

I want to do this because I'd prefer the lower maintenance costs and ease of replacement of these two components.

Am I missing something? Is there anything else a system boiler has or can do that a standard one doesn't have or cannot do?

Thanks!

 

[Simon F]

sounds like you are asking,
can an traditional/unvented boiler be made into a sealed system??
if the manufacturer says so then yes.

who is doing the work?
they would be the best person to be asking.

 

[ShaunCorbs]

yes you can and tbh i like them more

 

[joni os]

yes you can and tbh i like them more

Plus one with above. Then pump and other parts can be replaced, when necessary, with standard items, rather than dedicated parts at twice the price.

 

[ShaunCorbs]

Plus one with above. Then pump and other parts can be replaced, when necessary, with standard items, rather than dedicated parts at twice the price.

or cant get them as special parts

 

[CZFred]

Great. Thanks guys. Exactly. I'd rather be able to specify my own pump and EV too. And, replace them with bog standard, cheap ones, rather than the expensive ones specific to the [system] boiler.

So - obvious next question... ...I'll need 24 or 25Kw. Any recommendations, bearing in mind my set up?

 

[AWheating]

pressure guage, filling loop, pressure relief, expansion vessel, different wiring.

if boiler MI say its ok to seal then crack on.

make sure your Gas safe engineer fits the boiler (inc fixing to wall)

 

[CZFred]

Will do! Thanks.

 

[ShaunCorbs]

kw rating is down to your heating requirements and rid sizing etc heating engy will/ should do this

 

[joni os]

Viessmann boiler worth consideration.

 

[CZFred]

I'm thinking the Worcester 27Ri Compact. I won't have a lot of space, so... ...anyone recommend this, or not? Either way, why in particular? Thanks again!!

 

[ShaunCorbs]

I'm thinking the Worcester 27Ri Compact. I won't have a lot of space, so... ...anyone recommend this, or not? Either way, why in particular? Thanks again!!

What are your rad heating load ? And good boiler

 

[CZFred]

I'll need to get back to you on that. But there are 12 rads, and will be 14 or 15 once the loft conversion is added. This'll be split into 3 heating zones. One per floor.