Help! Its cold ;)

[sensph]

Hello,

I have a Valiant VCW GB242 EH combi boiler. There is hot water but central heating only works for about 10 mins. I have watched it and what seems to happen is the radiators get hot and then the boiler clicks off. This seems fine thats what its supposed to do? BUt then when the temp of the radiators lowers the heating doesn't click back on again. Even after 20-30 mins and the radiators are stone cold.


Has any one a service manual or suggestions? We have had a couple of boiler people around who just say its 15 years old and want to sell us a new boiler. However we haven't got the money for that!

Its getting cold around here and my familiy and I are starting to feel the frost!

I have looked at the boiler and ( to my eye) it looks in good shape. No corrosion evident any where . The pressure is normal at around 1 bar ( in the green) and doesnt sway about much. Although aa couple of time ( but not always) I have seen it go up to 1.5bar and I have had to twist a grey knob to lower the pressure a little.

Could any one send me a manual or give me some tips so I could get this working for maybe a £30 thermostat part or something rather than many hundreds, thousand for a new boiler.

I am a qualified engineer, know my stuff with electrics and electronics and generally reasonably handy but I know nothing about boilers and wont touch any gas work for good safety reasons.

Any things I can try that may help and wont blow us all up? Anyone be able to post me a service manual or troubleshooting flowchart etc?

Many thanks in advance for all suggestions.

Best Regards,


Simon

 

[gas4you]

Put your email in your profile, or email me and I will send you the manual.

 

[kevplumb]

Has any one a service manual

yes

or suggestions?

where is it going

 

[sensph]

Apols. I just singed up and forgot to put my email in the profile ( stupid).
Email is now in my profile.

Many thanks,

Simon

 

[kevplumb]

sent

 

[sensph]

Kev recieved manual A OK. Seems very comprehensive. I will follow through some over the fault finding flowcharts over the next day or two. One thing I have now noticed is that the "Flow temperature meter" (meter next to pressure meter is always at 0. OR actually lying fully to the left . I have checked an the wire looks to be in the meter ok.

Anyways thankyou VERY much for the manual. I'll dig the multimeter out and hit this tomorrow.

Very Best,

Simoin

 

[sensph]

Kev, Dave many thanks for the replies.

Kev many thanks for the manual.

3 Hours of troubleshooting by following the flow charts in the manual lead to the divertor valve.

There was a tiny amount of corrosion on the mecahnisim that pushes against the microswitches. The mechanism would stick minutely off pushing in the top microswitch. A tiny wire brush, a cotton bud dipped in WD40 and one turn of the adjustment screw later it works and the CH modulates correctly.

Family woke up this morning to a toasty warm house for the first time in two weeks. Smiles all round

Many thanks to you both for the help.


Best Regards,

Sincerely,

Simon