Boiler options

[Bunker]

I service a load of boilers at a school. In one boiler house (for dorms) they have a Grant 58/70 for CH and a Combi 70 v3 for DHW only.
The combi has been neglected and is, as you would expect, a rusted sieve.
DHW is required in 2 showers and 5 basins, 1 bath.

I suggested we just stick an unvented onto the 58/70 but they reckon they like to switch that off in the summer. I cant see running a combi all summer is much less efficient.

For some electrical reasons they cant have water heaters in the building, something to do with the supply.

Any recommendations?

thanks

 

[Roger Welton]

Definitely unvented, if they don't want it on the heating boiler then stick a 15-21 to do just the cylinder.

Alternately Andrews do a direct oil fired, though they are a bit of a pain to work on imho.
[DLMURL="http://www.andrewswaterheaters.co.uk/products_details.php?product=oil_fired"]Oil-Fired[/DLMURL]

 

[Killy Bing]

How many people do the dorms hold?

 

[Newpark7]

Never seen one of them before - Never stop learning

 

[Bunker]

The direct is a nice idea except I didn't say the combi also heats a towel rail in the shower block. My argument to them will be the cost of a buying, installing, maintenance, repair of a dedicated boiler to the cylinder compared to the slight loss of efficiency running up the large boiler twice a day.
Killy, ill check but not many I think.

 

[Killy Bing]

I would point out its better for the bigger boiler to kept in use!
rather for it to sit an seize up

If you reuse the old boiler
wire it up as a w plan with hot water priority
An acv smart 320 can take upto 73 kw!

can take the boiler on without it cycling.
not to mention they wont have any problems with hot water tbh!

[DLMURL="http://www.acv.com/gb-en/03_04/28/app.rvb"]SMART 320 - ACV[/DLMURL]

 

[WHPES]

edited

Beat me to it, was going to say the same thing

 

[Killy Bing]

edited

Beat me to it, was going to say the same thing

As my post?

 

[WHPES]

more or less

 

[Ermintrude]

Could even use SLME as a buffer / LLH?

 

[Bunker]

Thanks chaps, good advice (ill go try find out what it means!)