Please help! Worcester Bosch 240 problems BG unable to solve

[shonky]

Hi.
Im a new member with a problem (my expertise is AV so ill help out as much as I can there!)

Ive had a Worcester Bosch 240 boiler for nearly 15 years and had it serviced by BG yearly.

Earlier this year it developed a problem whereas the overheat switch would pop as I filled the bath (usually around 1/3rd full) It would be fine with the central heating or running the shower or sink etc.....The water would alwazs get hot.

BG were called out to solve the problem and swapped the thermostat cut of sensor plus a couple of other small items.

After they left the problem was still present so an engineer returned and fitted a new circuit board and adjusted a few settings.....He also added an earthing cable (which incidentally he did not sleeve....naughty!)

Anyway the problem was still present but I managed to find a way of filling the bath without the overheat tripping ( I would run the bath for a minute or so, stop it for a minute and then repeat..eventually I would get my bath!)

However now whenever you try and run the hot water it takes an age for the boiler to fire...I mean like 5 minutes.

You can hear the piezo clicking away but it doesnt fire, after a while it fires and runs hot for a few minutes then goes out.....If left running it tries to ignite and after another few minutes it fires again but soon goes out etc.

A total nightmare if you are trying to have a shower!

BG have told me the system needs flushing which will cost over £500 but the engineer didnt seem at all convinced that would cure the problem!

Any ideas as to what it might be?

Thanks in anticipation.

 

[DP]

Ive had a Worcester Bosch 240 boiler for nearly 15 years and had it serviced by BG yearly.

Serviced? in 10 minutes? I do not think so.

Kick up a stink or get an engineer who can locate and fix the fault instead of taling stabs in the dark

 

[nickso]

how on earth does a flush cure an ignition problem? keep calling them out 'til its fixed.

 

[shonky]

how on earth does a flush cure an ignition problem? keep calling them out 'til its fixed.

I know that!.....thats why I declined, they reckon that the heat exchanger gets silted up and that causes the overheat trip to go!

Ive called them out again for tuesday but im hoping to understand (a little more than they seem to) what the problem might be.

 

[nickso]

how on earth does a flush cure an ignition problem? keep calling them out 'til its fixed.

I know that!.....thats why I declined, they reckon that the heat exchanger gets silted up and that causes the overheat trip to go!

Ive called them out again for tuesday but im hoping to understand (a little more than they seem to) what the problem might be.

sorry, i missed the bit that said the original fault was still present.

well he is right the DHW heat exchanger can get clogged on these but a flush won't cure it, only stop it happening again. the DHW heat exchanger probably needs replacing, maybe even the primary if the water is bad enough. the O/H stat can also trip if the brass tee piece above the pump is blocked, only seen that on really badly clogged systems though.

 

[Jordon]

Sounds like it could be the pump,plate hex or main hex. Need them to test
it properly.

 

[adlplumbing]

ask them for temp reading on flow and return to heat ex when hot water running
if heat exchanger is scaled then it temp will rise till over heat kicks in
if does not then theirs is another problem

 

[DP]

Surely a repair person should not have to be told what to do. When he or she attends a malfunction, what is suggested should automatically have been done to correct the malfunction.

 

[shonky]

Surely a repair person should not have to be told what to do. When he or she attends a malfunction, what is suggested should automatically have been done to correct the malfunction.

In an ideal world. yes!

The problem is that it seems like the BG engineers are just stabbing in the dark!

Im asking here because I want to understand what might be the problem as they spend their hour here and tell me its fixed each time.

I have an engineer coming tomorrow between 4 and 6 so keep your fingers crossed

 

[nickso]

oh dear, 4-6 is the worst time slot in summer.

 

[Agile]

4-6 is hot, they are tired and looking forward to going home.

Probably as soon as they can get out of your house!

 

[breadnbutter]

ipossible hw plate or hw thermister fualt.

 

[nickso]

4-6 is hot, they are tired and looking forward to going home.

Probably as soon as they can get out of your house!

nope, it's the worst slot 'cos 90% of engineers will be knocked off by 4pm at the moment. that gives you the choice of backshift guys or the weirdo's that do overtime......that in turn means you have higher chance of being bumped after 4pm if the workload is high.

 

[Agile]

I would have thought that there is little overtime being agreed at this quiet time of year.

A dentist onece told me that he does his best work about 1130 am after he has just had a cup of coffee!

So I always try to see them at that time!

 

[nickso]

depends on the workload, all you have to do is phone dispatch and ask if they have any work left, if they do your on overtime.

most days they run out of work at 3pm round here.