In message , Stuart B
writes
I have an Alpha CD 32C Boiler and a wireless controller in the hall
which is fitted with a rad which has no TRV .Tonight I happened to
notice that this rad was cold at the top so I bled it and there was
quite a lot of air in it for some reason .

Later on I suddenly realised the flat was getting chilly and on
investigating I found that the controller was calling for heat but
that the rads were all cold .I went to the boiler and it wasn't
providing heat and the pressure was showing as zero and the warning
lights were showing ....I didn't note what the sequence was but I
think it was the sequence that means a low pressure .I topped up the
pressure and everything seems fine now .

It seems too much of a concidence that my bleeding this rad would not
have anything to do with the boiler stopping to operate but I cannot
understand why that would be and I like to know reasons for things
happening .

err ...

you have a leak

The air under pressure in the radiator which you let out meant that the
pressure dropped from marginally above to below that at which the water
pressure switch would allow the boiler to operate.

Have you been round and bled all the radiators again ?

and then repressurised ?

You need to find where the water is getting out and the air getting in -
you are diluting the inhibitor every time you add fresh water to the
system


--
geoff