Old Worcester Boiler Burner Issues

[yorst]

Hi there.

I have an old worcester combi boiler which has been working fine for the last 4 years (but I think it is at least 15 years old). In the process of installing a new kitchen this week, I got a gas engineer to connect a hob to the boiler\\\'s gas supply. The hob works fine. However, now when I try to turn on the boiler, the pilot light goes on ok but when I turn the hot water or ch on, the burners come on, the boiler makes a hell of a racket and the burners and pilot light switch themselves off.

Any ideas?!

Any help would be much appreciated.

 

[Slugbabydotcom]

The good news is that its nothing to do with your new hob
The bad news is that it could be something gone in your combi ..... such as a pump.
What model Worcester is it?

 

[yorst]

slhs 12 14
slhs 92210094

that make any sense?!

 

[Agile]

Not to me!

I like simple things like Heatslave 24 or 240 or 24i or similar.

Whatever the model it still sounds as if the pump is failed!

Tony

 

[yorst]

my pressure guage was slightly low and i also suspect that there may be a very slight leak. would either of these result in the blowing out of the flames?

 

[yorst]

btw tony - I have been reading some of the other posts - your diagnosis success rate is impressively high! I am hoping you are wrong on this one though - having just installed a new kitchen, installing a new pump in my boiler is not what I need!

 

[Agile]

If its the pump then you are lucky as thats one of the simplest tasks and one of the cheaper parts!

You might have a totally blocked main heat exchanger instead!

My success rate at diagnosing boiler faults is 100% at the boiler but that becomes very much lower when I have to make "best guesses" based on symptoms rather than the appropriate scientific tests.

I usually diagnose the fault in 5-10 minutes but the longest I have ever taken was 3.5 hours but that was a broken conductor inside the plastic sheath which had tested OK due to the carbon deposited when it arced. It was my fault for not testing for continuity but using the resistance range instead. I will not make that mistake again.

Tony

 

[yorst]

Good work Tony!

My next question is - if I do need a new pump - how is this fitted? Can it be done from the front/underside or will the boiler need to be extracted from the worksurface? Obviously - as my kitchen is brand new I am reluctant to mess it up by dragging the boiler out!

 

[mckinnon100]

I have the exact same problem with my old worcester. 9.24 rsf model. It switches on for a short while and then switches off. When it is on it makes a helluva racket.

Should I be paying £75 for a callout when the fault hasnt been found?

Thanks

 

[spacethegas]

 

[mckinnon100]

Sorry I meant to say that I had paid £75 for the gas engineer to tell me that he couldnt find the fault.

 

[spacethegas]

get your money back thats unacceptable.

 

[raoulduke]

hey there people. i have just moved into a new house and have a similar problem to the one above. i was hoping i could get some help from one of you guys...

pilot light will light and stay lit etc but when i try to draw hot water from the taps or switch on the central heating, the burners fire up and the usual boiler kicking in noise is heard, then within about 5 seconds the boiler makes an unholy noise (some screetchy / grinding noise and a little gurgling) and the burners and pilot both go out.

can anyone offer any kind of diagnostic techniques i can use to identify the problem? or repair methods if it is the pump / heat exchanger.

should also mention that when i moved in the system was completely drained down. i refilled the pressure in the boiler with the filling loop, bled all the rads and then ran off scared as soon as i put the tap on and heard the crazy noise. did I miss a stage by any chance?

also wondering what the tap (not the cold water feed) does on my boiler and where it should be turned to... fully clockwise? fully anti clockwise?

any help is muh appreciated!

thanks
colin

 

[kevplumb]

is the auto air vent open / working

 

[raoulduke]

is the auto air vent open / working

hi kevplumb, thanks for your post

sorry, but i'm not sure what the auto air vent is.... where should I look for it? how can I tell if its working or not?

the flames in the boiler are a nice blue colour so i think theres air getting in there somewhere

cheers
col