Boiler venting cold exhaust + radiators cold

[diychicken]

Hi,

I wonder if anyone has any idea what my issue might be. This has happened once before - about a week ago.

This morning, I woke to find that the radiators were cold. The pump in the cupboard where the hot water cylinder is was pumping and consuming 19W. The inlet pipe, normally hot when the boiler is on, was stone cold.

The wireless thermostat showed that the indoor temp was around 16 deg C and was calling for heating.

I went to the boiler in the garage and it was humming away normally, but the casing was stone cold (I think it's normally warm). Outside, the exhaust vent was pushing out gas (as it normally would) but it was cold - i.e. no steam - I could put my hand in the flow and feel the wind, but it was cold.

It's like everything in the system was working fine, but there was just no heat.

Then at around midday, we've suddenly started to get heat. As I mentioned, this happened about a week ago and the heat came at around 8.30am. The heating should come on at 5.30am and ask for 19 deg C and stay the same for the whole day.

So now it's as it there was never anything wrong - the house is warming up again.

Any idea what might be wrong? Boiler is about 17 years old.

Many thanks

Dave

 

[diychicken]

If it's of any use, the boiler is a Glow Worm Ultimate 40FF. As I mentioned above, it's at the back of the garage. The previous time this happened was the 16th where the outdoor temp went down to -4 deg C. Last night it was only -1 deg C, apparently.

Thanks again

 

[jeff the gasman]

Job for a gas man Dave.
Obviously a boiler issue.

 

[diychicken]

Thanks Jeff. I'll call one out. Thanks for your reply.