On Sun, 4 Jan 2004 10:52:36 -0000, "Malcolm H"
wrote:

I have a Glow-worm Fuelsaver 40-50 conventional flue boiler which was
installed in 1984.

Everything works fine except that the central heating circulating pump stops
running as soon as the room thermostat reaches the desired temperature.
This results in some noisy bubbling from the boiler as it overheats for a
short time after the room thermostat switches the pump and boiler off.

Does anybody know if this boiler was designed to have a pump overrun feature
to avoid this problem?

Yes it did. I used to have one until a year and a bit ago.

The pump over-run is provisioned by a separate set of contacts on the
thermostat. Either the pump was never wired to them, or as on
mine, the thermostat has failed.

When I enquired regarding the cost of a new one it was in the £70
range. Since this followed a failed thermocouple (that admittedly
only cost £2 to replace) I decided that the boiler was at the end of
its useful life. These things are a piece of junk anyway. I
was never able to dismantle it without cutting myself on sharp metal
somewhere.

Considering also that they run at 65% efficiency at best, I felt that
spending money on a new thermostat was pointless and put it towards
the cost of a new condensing boiler instead.




If the boiler was not designed to have a pump overrun feature is there a
control available which can be added retrospectively. e.g. is there a timed
control available which will allow the pump to run for a short time after
each switch off?

You could do this with a stairway lighting timer.

Have a look at rswww.com part number 277-3520

It has a mode whereby the output remains on for a time after the input
drops.



TIA


..andy

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