"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...
Doctor Drivel wrote:

"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...
...
Reliability is more about make than type, although a system
(regular-type) boiler is less complex than a combination boiler.

Not much at all. A combi is system boiler with a 3-way valve and a
plate heat exchanger for DHW. 90% is the same.

That is still more complex than a system boiler.

Not much.

The other advantage of a system boiler is that the hot water is stored
in a tank, which can have a backup immersion heater and that gives you
belts and braces cover.

An in-line instant electric heater can be fitted in the combi outlet. A
small box say under the sink.

They are fairly useless if you want to fill a bath though.

It is for backup and will do a shower.

If you want full backup have two boilers and one being electric and a backup
genny as well. Where do you want to stop?

Both types are available as modern condensing boilers.

My personal preference is for a Vaillant system boiler and mains
pressure hot water tank, both of which are sitting in my side porch
awaiting installation.

A poor choice as the unvented cylinder is a potential bomb.

Worse than a couple of air receivers working at 11 bar?

Uh?

Unvented cylinders need an annual service costing £60-£100 a year.

Wow, a whole pound or two a week.

That is £100 in 10 years. £2000 in 20 years. Not economical at all. Sell it
now!!!!

The best, if you have the mains pressure and flow is a high flowrate
combi.

Been there, tried it, did not like it.

Which one? What kW? You never tried an ATAG

Floor mounted like the Worcester-Bosch 550 or wall mounted like the ATAG
51kW. The ATAG is quality. It works out cheaper to fit and install and
saves a hell of a lot of space and no bomb in the house or need annual
service expenses.

You don't have your gas boiler serviced every year, but worry about the
dangers from an unvented cylinder?

I do not have my boiler serviced? It is mandatory to have the unvented
cylinder serviced.