I have a Glowworm Mk I. If the pump is going too fast, it suggest a lack of
water in it which could be very dangerous for the boiler and persons
standing too close. The boiler water can't be totally drained in mine as
the feed pipes are at the top and half way down, so in the absence of a
water supply, the burner will heat up what water is left in the boiler,
until the boiler thermostat switches the gas off, which on mine would take
one minute or so.

this is just a worst case scenario....... check the pipes to the boiler for
temperature. If they are cold, they may have no water in them.

"Markus Splenius" wrote in message
...
On 1 Feb 2005 02:40:56 -0800, "doozer"
wrote:


Anyway a few more details. The most dangerous thing that happens, IMHO
(please excuse the fact I don't know what all the various bits are
called), is when the boiler fires up but the hot water produced is not
pumped around the hot water tank or the radiators (the pump goes ten to
the dozen and sounds like it's trying to tear itself off the pipe). I
am fairly sure there must be a safety cut off because under those
circumstances the boiler does go off briefly. The Honeywell controller
/ timer box, an ST6400C (http://www.plumbworld.co.uk/acb-1357), has
been bodged on to the wall (previous owners fault) and tapping it, even
very lightly, with my finger can cause the heating or hot water to come
on.

If I had to make a guess I would say that it is the controller / timer
box but I don't know for sure. Any ideas?