"Stephen" wrote in message
...
On Tue, 5 Aug 2008 23:00:07 +0100, "Doctor Drivel"
wrote:

Outdoor boilers are a great idea, Keep the stuff out of the house.
Fitting
an external oil combi is a great idea - all outside.

Making space in the kitchen is a definite plus point but OTOH I'm
still concerned about an external one on a cold day during a power
cut, wouldn't it freeze then? And I had not appreciated what others
have said about it being uncomfortable to work on in winter weather.

I do not have a combi. I have a HW cylinder. Perhaps combis are better
that you only heat what you need. I doubt we use a cylinder a day.
What advantages are there to having cylinders: better flow rate and
the ability to connect a shower?

Oil combis tend to have higher flow rates than gas combis for the equiv kW.
They hold more hot water in the water jacket and this is used as a thermal
store for the instant DHW side giving higher flowrates. Many hold 30 to 50
litres of hot water.

You have mains pressure showers. Most will fill a bath quickly enough too.
If the DHW side fits the bill get an external oil combi. As I say, all is
outside in an insulated box. The way to go. No smell, no nosie, "safer" and
more space.

I have seen the odd small insulated boxes or "sheds" with gas combis in and
the pipes to the house via 110mm drain pipes filled with insulation.

Many servicemen like the external boilers as they don't have to worry about
making a mess inside a house.