boiler shutting off

[neilinbal]

am just fitting a shower downstairs at home i have a vokera 28kw combi boiler about 20yrs old. it has been working fine with no probs until now. as soon as i turn on the hot water to the shower the boiler fires and all is good but if i turn the hot up full the boiler kicks off immediately. Have messed with putting an iso valve on hot pipe and restricting flow and this works but then the shower is ****.... any sugesstions
thanks

 

[bengasman]

A 20 year old vokera not performing well? Might be time for a new boiler; I would not recommend spending any money on a vokera that old.

 

[neilinbal]

don't know why i said it's a vokera must have had a nightmare about them.
it's a baxi
does this change things?

 

[bengasman]

Still don't think I'd want to spend any serious money on a baxi combi that old either.
Which model is it?

 

[Agile]

Danny ( DP ) would always expect to renovate a 20 y.o. Vokera.

Few would want to do that to a Baxi. Its rare we see many old ones still working anyway!

Tony

 

[baxpoti]

Few would want to do that to a Baxi. Its rare we see many old ones still working anyway!

Tony

Bermuda, Boston WM etc

 

[neilinbal]

so does anybody think that i need to get a spare part for the boiler? whats likely to cause this problem cos i'm pulling out whats left of my hair and i dont even know where to begin. any advise would be welcome
cheers

 

[mickyg]

boiler model would help mate.

 

[DP]

There is a well known saying about bad workman and his tools. This replacement lark is getting to be a little like another thread where a boiler has been condemned without removing its cover or a look see.

Little worrying when pros are getting on the boiler replacement bandwagon.

 

[bengasman]

Danny ( DP ) would always expect to renovate a 20 y.o. Vokera.

Any advice on the lottery numbers for next week?

 

[hobhead]

Is the hot water ok at the hand basin/ kitchen sink? Is the flow very much better from the cold than the hot water?

 

[neilinbal]

there are no markings on boiler other than baxi and no book. there used to be a problem with boiler making a right racket when hot tap was turned on but after a good clean out worked fine. the hot water and cold flows are about the same and very good. the upstairs shower,basin are good but the down stairs basin,shower and sink shut the boiler off when hot is turned on full.