"wattie" wrote in message
...

"IMM" wrote in message
...

"Colin eclipse 2" wrote in message
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I know - done to death.. A customer has asked me this question. I have
come
up with the following list. Any other thoughts - sensible ones.. no
need
to
start a debate about the merits - just need a list!

Conventional
Pros
Stored hot water - so water (hot and cold)
available if mains supply fails

-This is so rare an event that is it is not worth taking into
consideration.

Immersion heater backup - hot water if boiler or gas fails
Warm airing cupboard

That can be achieved with any heating system, so not so.

Cons
Cylinder needs replacement (in this case to comply with building
regs)

-Cylinders may need replacing every 8 to 10 years in hard water areas.

Storing hot water not as energy efficient
More complex controls
More costly than combi to install

-Very poor shower pressure, having to use an expensive and noisy power
shower pump in some situations.

-The cylinder takes up space.
-Ugly zone valves and pumps around cylinder.

Combi
Pros
High pressure showers without pumps
Only heats hot water you use
No stored water (flooding issue)
Frees cupboard space

-No wating for cylinder to reheat
-HIgh pressure shower after shower can be taken.
-Have a high output, so house warms up faster.
-All the system is inside the one white box.
-No pipes to freeze in the loft

Cons
slower bath filling

High flowrate combi's are available, so not true.

No warm airing cupboard

A small rad can be installed in the airing cupboard taking up no space.

Where do you buy these 'zero volume' radiators? I could do with a few of
them!

The ultimate zero volume rads are forced air or underfloor heating. Go for
it.