Worcester 240 Combi Problems

[silentwitness]

Hi all

After done help with a Combi boiler. We have had problems with it for a while. I have just replaced the diverter diaphragm as it was heating the rads when just the hot tap was on.

The fault we have now is it's tripping out. It is fine on central heating. If is also ok if the hot tap is only on low flow. But if we run a shower it lasts a few mins then trips out. It can be reset but trips again soon.

We are renting the house out soon so desperate to get it sorted!!

Thanks a lot

 

[boilerdoktor]

1) the gas valve may be overgassing and not modulating
2) the calorifier may be blocked
3) faulty dhw stat (doubtfull on these)
4) cross leaking in the house at a mixer tap or mixer shower!

The only one really you can check is 4.

Isolate the cold feed under the boiler (2nd from left i think on those) and turn a hot tap on around the house. if water comes out then its cross mixing and it will be a shower prob. If not then you need to get someone out whose good on boilers. how old is the boiler, it could be up to 19 years old (date on data badge) if it is a particlarly older one I wouldn't spend hundreds on it.

 

[silentwitness]

Thanks very much for the reply.

Let ne check i have this right. I isolated the cold feed under the boiler andcran a hot tap. Water does flow out! Should I check the shower mixer then?

Cheers

 

[kevplumb]

yes

 

[silentwitness]

ok thanks. Should I do this check with the boiler on or off? As I don't want to run in dry if the cold is isolated?

Cheers

 

[silentwitness]

Also, could I ask if it is cross mixing why does that overheat the boiler?

Thanks again

Col

 

[boilerdoktor]

because cold water is filling into the hot water side and the hot water in the boiler can't get away causing it to overheat!

 

[ks52]

More than lightly the main burner is not modulating, sensor still available,,,worst case senario calorifior choked. Gas man req. Simple case for someone qualifyed to diagnois or however it is spelt.