Doctor Drivel wrote:
"Fitz" wrote in message
oups.com...

Dave Fawthrop wrote:
There is a disagreement in another thread as to the adequacy of hot
water
supplies from combi boilers.

There must be lots of people here with them, so will these people ple=
ase
answer the question
"Are you satisfied with hot water from a combi boiler, without extra
storage".

Cor, what a lof of fuss some people have made about answering this...

I've lived in 9 different premises in my 30-odd years on this planet
and obviously visited friends relatives, stayed in hotels blah, blah in
countless others.

Of the 9:
4 were stored hot water systems.
1 was a university halls of residence with a giant site wide heating
system
4 were combi boilers.

Obviously the best for everything was the halls of residence. Never
ending hot water at a million liters a minute (approximately ;-)

Of the combis only my most recent has given truly acceptable
performance. It's a new Worcester Bosch Greenstar 35kw. We only have
a single bathroom and use a dishwasher for 95% of dishes. It provides
a very nice shower admittedly at the lower end of acceptable pressure
range. The bath is filled within about 10 minutes which I gather some
people think is a long time. Personally I never have 'emergency' baths
and can easily kill 10 minutes. It does a very, very good job of
heating the house and with the trv's on most rads we have a constant
temperature throughout the house. I think this was actually more luck
than judgement, but the modulating ability of the boiler does keep the
flow ticking over at a low temp in milder times.

The other 3 combis were smaller and older and performance varied, from
utterly unnaceptable to liveable with. A friend of mine is selling a
house where the combi will take an hour to fill the bath. I didn't
believe it until he showed me the flow he was getting. I can't help
but think something is wrong with it.

Of the stored systems all were open systems so relying on gravity for
the pressure. The only one to provide a good shower was boosted by a
noisy pump. The tank was quite small and would run out if we had 4
people to get through the shower.

If I had more bathrooms than I do now I'd like to fit a sealed system
with a stored water capability, but I'll do this as part of an
extension if I ever have one.

So there you go. I do think combi's have there uses but I'm aware of
the limitations as well and would look to a different solution in more
demanding cirumstances.

You have made an assessment on limited experience of combis. Most of this
thread is utter ********

The highest flowrate are floor mounted combis: W-Bosch Highflow 440, Voke=
ra,
Potterton Powermax, Ideal Istor, Viessmann 333, ACV Heatmaster (Stainless
steel hybrid of thermal store, serving the CH, and unvented cylinder and
heat exchanger running through the store, which will deliver 38 litres/min
for 10 mins then drop to 15 litres/min). Beat that!! "never" runs out of
hot water. Hard to on any system.

Welcome back IMM. The high flows rates of the ACV attracted me. I
looked up the ACV (I have never heard of it) and it looks a substantial
piece of combi with a stainless steel tank in tank, which is a cylinder
immersed completely inside another cylinder. The price is about =A32,300
with quality to boot. That sounds expensive, yet if you buy a stainless
steel tank in tank, or just a standard stainless steel unvented
cylinder and a quality condensing boiler of 35kW, after buying all the
controls, you end up paying more than =A32.3 K. It is one of the most
efficient boilers in sedbuk and the dealer said they have good backup.
I am about to order a Rinnai for two Triton tower showers and a boiler
for the CH. I may reconsider and look at the ACV more depth. It is
slightly bigger than a Powermax about 600mm square, and 5.5 foot high,
making it easy enough to go in lofts. The Rinnai never runs out hot
water so can deliver the flow and no time limit to showers.

I'll let people know what I do and how the Rinnai performs if and when
it is installed. I looked at the ACV manual and can't figure out in
detail how it works. Any ideas? Do I have to be BBA approved to fit it?

Wall mounted models with v good flowrates are the Alpha cd50 and
ECO-Hometec.

Want instant water at the taps? Some have a small vessel inside, some ha=
ve
a "keep warm" heat exchanger, and all can have a secondary circulation lo=
op.
Dead leg pipe is a problem with "all" systems,

As many of the idiots on this thread spurted forth, combis are full of si=
lly
old wives tales, which are untrue, pasing off old crap models as the norm.
Want two baths to be filled simultaneously? One can do it. Just choose =
the
model.

Then there is the high flowrate Japanese multi-points which belt out the
flowrates.

I read back on some of the threads. I believe Plowman is shagging Mary. =
Is
that true?