I have a Worcester combi boiler which is about 11 years old. It is
under contract with B Gas. Recently it started blowing pilot out.

What happens is that if you turn on the hot water (tap or hot water)
its works ok for about 5 mins and then there is a clicking noise and
pilot and flames blow out. I then have to light the pilot by firing
the button 5-7 times. It will work again for about 4-5 mins and same
happens again - clicking noise, flames/pilot go out. This happens
consistently on hot water. If we use the central heating then it may
blow out 1 or 2 times in evening.

I have called out Bgas 3 times and they have not been able to fix it.
They have changed a thermostat and then a sensor but without luck.
They are now saying that the boiler is too old and needs replacing.
And CH also needs a power flush to get rid of debris. They say there
is no other remedy.

Now if there was debris that was causing the tripping then I would
expect this to happen more on the CH side rather then the hot water. I
would also expect the tripping to be random rather than consistent.

I am totally unhappy with B Gas being unable to find the fault and
telling me to replace boiler. Yes the boiler is old but it has had
about 60-70% of the components replaced in the last 2-3 years. I am
paying them 16.75GBP per month and I think they are not putting in the
effort to find the real fault.

One of the things I have noticed is that when we used the hot water
before, it used to get really hot after 4-5 mins and it used to go
into a rest mode and started up again after a minute or so. Its not
doing that - it just trips now. I told that to the B Gas engineer and
he repleced the sensor but it has not made any difference. Is it
possible that the internal is not receiving enough air (fan maybe
faulty)?

I think there must be another reason for all this other than the
debris.

Can you please give me some advice/pointers as I am going to call out
B Gas for the last time.