combi boiler problems-any help?

^opm^

posting this on behalf of my mom-
her combi boiler has began to get tempremental-she has hot water when ever she needs it but sometimes when she goes to switch it onto heating the boiler wont light up and the little flow meter then wont show no flow-other times it will work ok-its a valient make and all heating engineers she has rang up have said they are a pig to get hold of bits for and its best to go direct to their own engineers-but when she rang them up they wont even take a booking till january, then its a call out charge of £175 i think she said.
Could it be something simple as sometimes it does work-like a bad connection on something?

Browntoa

vaillant are easy to get spares for, unless it's a really old one

what model is it ??

do you know how old

^opm^

model number is VCW-GB-242-EH
and she thinks it was put in house about 1991

also says even when working which it is doing now it seems sluggish? i think she means the flow meter seems slow to get up to normal level by that.

Browntoa

I take it the minimum pressure on the system is set ?? there is a bit of the boiler that displays the pressure, it should be set to about 1-1.5 bars , normally a round guage with a green section

if the prssure is low there is normally a filling loop under the boiler

^opm^

just rang her up-she says she always keep water at right level and its reading between 1 and 1.5 bar all the time-on another forum a person says this-

Sounds like the diaphragm washer on the diverter valve is getting stiff and so wont operate the micro switch to turn the boiler on, the washer is £2 and about £50-100 to fit it.

if this is case can a normal-ish person do job or is it a job for a specialized person?

sionnach_2

this might help as a temporary fix, run the hot water tap so the boiler has fired up and then flick the switch over to boiler, it sounds to me like the valve is sticking