In link http://groups.google.co.uk/groups?hl...p%253Duk.d-i-y


"Andy Farrall" wrote in message
...
Can Oil Combi Boilers be sited, for example, on the first rather than ground
floor. It makes sense to me to site the boiler where my hot water storage
tank currently is (airing cupboard) as all the neccessary pipework is
already there but im not sure about the ability of the oil to travel
"uphill" ???


The boiler can be sited at whatever level you like BUT you must make
provision to get oil up to it. A normal installation will use a
flooded
suction to the burner with the oil tank slightly above the burner
level.
A normal wall mounted boiler which is higher than the bottom of the
tank
will use a two pipe supply from the tank OR a Tiger loop device
which is a
deareator and can cope with a negative working head of about 0.4 bar
(any
higher and the oil pump might suffer vapour locking.
If you really want to go down the road of higher elevations than
that you
could use an elevated supply tank for the burner inlet and a lift
pump from
the main oil tank to it, controlled by a level switch system or an
overflow
back to the main tank. In either case you will waste energy lifting
the oil
and introduce a host of technical problems which include
environmental
protection from spillage/leaks, fire protection to your premises,
higher
maintenance demands with attendant cost, etc etc.
What you suggest is occasionally done industrially where higher
costs are
sometimes acceptable but rarely domestically


I have a grants 90btu MKII oil fired combi which cuts out regularly.
It has the oil tank in the basement and the burner on the ground floor
I would say approx 2m above the bottom of the boiler. I believe it has
a two pipe tiger loop setup. Is that distance likely to cause the
negative pressure to be greater than 0.4 bar?

How do you calculate the negative bar? That'll impress the engineer
when he turns up this week.

As well as the above the system has no thermostats other than the
stats in the boiler itself. no room stats, no frost stat, no rad
stats. I thought that would be a fairly standard setup these days -
are there building regs regarding use of stats in new build houses?

When the CH does get going without the boiler cutting out, the rads
can be "too hot to touch".

The boiler is one of these with an internal 40 litre tank which is
kept hot so that there is DHW on demand. But at nighttime the echo of
the boiler can be heard in an adjoining bedroom. Would it be ok to
connect an external timer so the system is off totally between say
10.30 pm and 6am in the morning. Presumably this would mean bypassing
the internal timer which is one of those "lug in for on" and "lug out
for off" jobbies.

One other point which I hadn't considered was air in the system. What
is the correct procedure for bleeding a combi system? I always worry
about putting too much pressure in the system.

A Service Engineer who has worked on these boilers for 20 years is
hopefully coming out next week. What sort a questions should I be
asking him? The builder is prepared to pay the bill "if it isn't too
much". But as far as I can see this is a poor standard of
installation, with the possibility that the boiler is faulty as well -
there is a smell of fumes in the utility room - which has no
ventilation other than the flue of the boiler itself.

Replace the _ _ _ with @ . . and remove the ".hotmail.com" for a
personal response which would be much appreciated.