"YAPH" wrote in message
...

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
...
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?

The typography of the lettering on the front is like that on some early
Worcester (as in Bosch) wall-hung boilers, so the GC number mapping to a
Thorn EMI Marathon (which was indeed a floor-standing boiler - my mum had
one until recently) does suggest some sort of transfer of business from
Thorn EMI to Worcester.

It is a Worcester Heatslave - it says on the box. They used the Thorn
boiler because it was very slim for the time and could fit in the box. It
was the first combi in the UK in the 1970s. I forget the operation. It may
have been a thermal store coil inside or maybe an external bubble type of
heat exchanger to heat the water instantly. They were used in flats and the
larger burners in some houses. They were reliable enough but expensive -
but cheap if the tanks and cylinder in a system are eliminated in an system.
It suffered from ignorance by bathroom changing plumbers, who never
understood it - nothing has changed - and were put off by the high price of
the "box", not doing the sums for the whole system, which case it was
cheaper. The Heatslave went through many serious improvements as combis
improved spurred by Vaillant, and the name today only applies to an oil
combi I believe.

Parts are pretty well available today, well the main control parts.