In message , Roger Mills
writes
I've just spent a few days in a holiday let in Cornwall, where the heating
and hot water was provided by an elderly-ish boiler which was unfamiliar to
me. Since one of the days was wet, and there was little point in going out,
I decided to investigate and take a few pictures - as one does(!)

The boiler was installed under a kitchen work-top, and was about the same
size as a dishwasher. On the front it said "Worcester Heatslave 2+", and the
model number shown on the rating plate inside was 30/42B - as can be seen
from:
http://www.mills37.plus.com/boiler_front.JPG and
http://www.mills37.plus.com/boiler_plate.JPG

Inside - in addition to the heat exchanger, gas valve, etc. - was a lagged
hot water tank, a pump and (according to the circuit diagram) a motorised
valve - although I couldn't see that, so it was probably behind the control
panel (which I didn't think I'd better dismantle!). The inside looks like:
http://www.mills37.plus.com/boiler_inside.JPG

A Google search on the GC# shown on the rating plate led to a record in the
Sedbuk database, as follows:
"001112,000005,Thorn EMI Heating,Thorn EMI
Heating,Marathon,30/42b,4178945,,1983,1,1,1,1,1,2,1,8.8,12.3,,,65,3,,0 ,2
,1,20,0,0,,0,0,,,,,,,,2000/Feb/28
09:58"

I don't know what the column headings are, but Thorn EMI is presumably the
manufacturer, 30/42B the model, and 1983 the year of manufacture (there is
other evidence that that's when the flat was built - so seems reasonable).
On the back of the door there was a manufacturer's contact number starting
with 0905 (Worcester, before the '1' was later inserted).

I presume that Thorn EMI were using the 'Worcester' brand in the 1980's. Is
there any connection between this and Worcester-Bosch?

I'm not sure whether or not the boiler is a combi - anyone care to hazard a
guess? The primary side is vented, with a small F&E tank in a cupboard. I
could find no header tank for the DHW - which appeared to come out of the
taps at mains pressure. There was also no hot cylinder external to the
boiler - but I guess that the internal tank held several gallons. If you
turned the boiler stat up to High, you could get a reasonable bath fairly
quickly before the water ran cold.

Are there any boiler archaeologists out there who can shed any light on this
beast?

As you say, its a Worcester (9.24?) Heatslave, a fairly common boiler in
its day

Prolly got a manual for it somewhere


--
geoff