"Fatboise" wrote in message
...

Just wondering if anybody can help me out here. I have an oil fired
boiler for the central heating and hot water. We've been in the house
for a few months now and we seem to be using a lot of oil and I'm
trying to see if I can get the boiler running more efficiently

Now it's a big house (2600 sq feet) and I understand that a house that
size will be hard to heat. The heating would be on inthe morning for an
hour and in the eveniong for 2-3 hours. There is 15 radiators and the
hot water cylinder. The boiler is 120000 Btu (35Kw) with a 0.65mm
nozzle in the burner.

A few days ago I timed the cycling on the boiler when it was up to
temperature and found that the burner was coming on for 2.5 mins and
then of for approx. 2.5 mins which I thought a bit excessive.

I've tried searching for info but find it hard to find anything on the
boiler cycling question. I had a look at the sedbuk website but don't
have all the measurments to size the boiler - need to find the drawings
again.

Any inputs much appreciated.................

You have three alternatives:

1. A new modulating boiler (expensive)

2. A heat buffer. A cylinder, can a cheap normal direct domestic cylinder,
that the boiler heats up directly, not via a coil with two cylinder stats
that prevent boiler cycling. The CH can be taken off the cylinder and TRVs
on all rads using a Grundfos Alpha auto modulating pump. The DHW can also
be taken off the buffer cylinder, or have a quick recovery coil cylinder,
again with two cyl' stats and taken off the boiler directly.

3. If you have good mains pressure install an 'integrated' heat
bank/thermals store, again with two cyl' stats, CH off the store directly
with Alpha pump. The cold mains water is heated via the heat of the stored
water. Explanation: http://www.heatweb.com

With 2 and 3 above the boiler comes on for one long efficient burn to heat
the stored water. Only when the water cools off substantially does the
boiler come in to fully reheat. With 2 and 3 above, install a magnaclean
filter on the CH return to the buffer or thermal store.