Doctor Drivel wrote:

"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.

I don't want to fill a bath slowly and, with a cylinder backup, I
wouldn't need to.

Get a shower you filthy person.

I have never been taken with showers. It is far nicer to relax in a bath
full of hot water.


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.

No use to me, for the reasons already given

Saves
space,

Not a problem

no annual service charge

So what?

and will not take down the side of your
house.

Nor will a properly maintained unvented cylinder.

You will die.

We are all going to do that.


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.

So, something that is designed to work at about 6 bar and that normally
contains an incompressible fluid is more dangerous than something
working at nearly twice the pressure and that normally contains highly
compressed gas? You really have no idea what you are talking about.

See my other post with evidence of catastrophic explosions.

None of which appear to have happened in Britain.


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.

Have you not yet realised that trivial savings are of no interest to me?

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

And would be massive overkill for me, as I am installing a 15kW unit.

- also has weather compensation as well..

Optional on the Vaillant, but I wouldn't have got my trade discount had
I gone for it.

And beat
any unvented cylinder.

Not in my opinion

You have never heard of one.

So, how did I know they are Dutch?

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.

Again, so what?

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

As it is with air receiver safety valves.

----

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.

I need 210 litres of water, not all hot, once a day for my bath. I would
have gone for the 125 litre tank, but there was a special offer on the
155 litre one and it was in stock.

No contest in DHW
delivery.

Massive overkill for my needs though.

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?

No, but I do know what a 155 litre one costs and I have it sitting in a
box awaiting installation.

You have bought a second rate, old hat, dangerous, system.

As I said elsewhere, you are entitled to your opinions, but don't expect
me to share them.

Listen to
the professionals

I did.

you sycophant.

Your repeated use of this word in completely the wrong context can only
lead me to conclude that you have absolutely no idea of what it means.

Colin Bignell