Another what boiler question....

[trevt]

Hi

I'm looking for advice, the background...

We have just completed on a repossessed property that needs a lot of work including re-plumbing and central heating. Previously it had a vented system but the exchanger has been ripped from the boiler, the cold & hot water tanks are gone and the back boiler/solid fuel fire are all gone. The LPG tank has also gone.

So we are looking at a full new central heating system to support a detached 4 bedroom dormer with 2 en suites and a bathroom all with showers. It would be possible for all 3 showers to be running at the same time, hence we plan for one to be electric. Bottom line is we need a high flow rate for hot water, we also like v hot showers.

Been looking at combi's with high flow rate - 15 + litres/min - is this about right or too much?
Looking at circa 30kw output - again about right?
And finally which make - thinking Vailliant, Worcestor/Bosch or Gloworm?

Should I consider any other makes? Main drivers, in order of priority, are reliability; efficieny; cost; and ease of installation/maintenance.

Many thanks for any guidance.

 

[Dan Robinson]

A combi is a daft choice IMHO.

You want a modest Unvented cylinder and I would guess no more than 18kW of boiler.

 

[trevt]

Happy to take the advice, but what's the rationale?

My view is based on running through the size of house etc on the vailliant website and they suggested the biggest (probably not surprising). Also my wife wants a combi as she tired of no hot water if one of us has a bath or she's third shower in the morning - our current house has a vented system with HW tank.

Cheers

 

[dcawkwell]

Glow worm ultrapower cross between combi and tank.
Sorted.

 

[Dan Robinson]

Your house is very unlikely to need 30kW for heat.

No combi will do what you need for hot water.

Modern Unvented cylinders reheat in 20 minutes. Sized and controlled correctly you should never run out of water.

My rationalle is based on over 13 years experience and a lot of research. Have a look at my albums.


You cold go for a Viessmann 111W or 222F, or the Glow worm, but they might struggle if you truly use the water the way you suggest.