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

"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.

I don't have a shower or a shower attachment.

Some will fill a bath slowly. Get a shower you filthy person.

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

An immersion heater in the hot water tank will do me. I said backup, not
paranoia.

Yep a combi and a small inline instant backup electric heater. Saves space,
no annual service charge and will not take down the side of your house. You
will die.

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

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

Uh?

It would seem to be a simple enough question. Is an unvented cylinder at
mains pressure a greater danger than two similarly sized air receivers
working at 11 bar?

yes. See my other post with evidence of catastrophic explosions.

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!!!!

Interesting maths. £100 in 10 years = £2000 in 20 years. In any case, if
that really worried me, I will be saving more than £1000 a year in road
fuel when I downsize to a 2.5 litre diesel Mercedes E Class in September.

We are on about water heaters not your frigging car you sycophantic idiot.
It will be more like £3-4,000 over 20 years as service prices rise. Then
replacement of expensive pressure valves.They are NOT cheap at all.

You never tried an ATAG

I can't say I have ever rated the Dutch as world leaders in engineering.

They are now in combis. They invented the condensing boiler. A 51kW ATAG is
a class act - also has weather compensation as well.. And beat any unvented
cylinder. You have never heard of one.

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?

You claim no annual service expenses

No annual service on just have a cylinder of water. You will have to pay a
service on the boiler AND unvented cylinder.

Read on.....

BS-approved UDHW systems training manual, under the heading of maintenance,
p40:

"the installer is responsible for the safe INSTALLATION of the unit. He/she
must also make his customer aware that periodic checks of the equipment are
ESSENTIAL FOR SAFETY... some manufacturers recommend a MAXIMUM of 12 months.
Experience of local water conditions may indicate that MORE FREQUENT
inspection is desirable."

BS6700: 1997 states that with unvented cylinders, the "maintenance and
periodic easing of temperature relief valves is particularly important".
----

Send the stuff back and buy an ATAG 51kW combi you plantpot! An ATAG will
deliver 24 litre/min that is 1,440 litres an hour. Your 150 litre unvented
cylinder will manage about 350 litre/hour. No contest in DHW delivery. And
it is only a box on the wall. Have you priced up a 1,500 litre unvented
cylinder? Have seen the size of one?

You have bought a second rate, old hat, dangerous, system. Listen to the
professionals you sycophant.