Worcester Bosch Combi Ignition Lockout

[nthused]

Hello all,

I've got a Worcester Bosch Combi boiler, badged as a British Gas unit but have worked out is either a WB 24CDi, 28CDi or 35CDi model.

There seems to be a problem with Ignition Lockout. The unit can be on for either 10 minutes or 10 hours, totally random time period, and then enters the ignition lockout state. I think that the burner is trying to re-ignite after the thermostat kicks in, doesn't re-ingnite and then enters the lockout state. The unit can be reset manually, but if the central heating is on for any number of hours, sometimes it has to be reset several times - after each one of these events. It's not a major issue to keep resetting but this clearly shouldn't be happening.

I'm not a boiler expert, but I'm guessing this one might be a quick, no-brainer for those in the know.

Can anyone help?

 

[Kristoflampie]

Had this last week on a 35cdi , PCB appeared to lose flame signal after a random time but worked ok whenever we appeared. Changed PCB after 3rd visit and we havent heard from him since. Its a thought.

 

[bengasman]

could also be lack of gas, low pressure, faulty lead, duf electrodes, lack of service or overheating.
when was the last service?

 

[Agile]

Hello all,

I'm not a boiler expert, but I'm guessing this one might be a quick, no-brainer for those in the know.

Can anyone help?

Its easy for you to guess that because of the common perception that those who mend boilers are called plumbers and, as everyone knows, they leave school at 14 and are thick!

Of course the reality is a little different ! Boilers are not quite so simple and a single fault like an ignition lockout can be caused by many different reasons as indicated above.

The first thing to avoid any simple causes would be to have the boiler properly serviced by a competent boiler engineer. That is not a safety check by British Gas, but a proper service which involves opening the combustion chamber and checking all the gas settings.

Tony

 

[nickso]

24/28cdi is the same boiler. 35 cdi is different. you need to find out which it is for accurate help.

my first guess would be low ignition pressure.

 

[nicknox]

And my guess would be flame sensing electrode out of place or faulty.

 

[nthused]

Thanks for the replies,
I think a service is the way to go on this one.

 

[Agile]

Some rather questionable housholders call British Gas for a "service" in these situations.

They come and do their "safety check" and if no other indications are given they say its fine and thats it!

Then a few days later the householder calls BG again and says that after their "service" the boiler is giving random lockouts.

Being a large firm they will then come out again and probably sort out the problem for you at no further cost.

Now, I am not suggesting that you or anyone else does this. I am only noting that some people do it.

Do any BG engineers have any comments to make about this?

A good independent who is opening up the boiler and doing a proper service might well overcome the problem from the servicing work he does.

Tony

 

[nthused]

Thanks Tony

I think I would tend towards going with the independent engineer.

My original quote regarding this fault might be a "no brainer for those in the know" was based on getting a reply from someone in "the know" and also that this may be a common fault for this/these model(s). However, this has been cleared-up with respect that the cause is inconclusive and, like in many situations, can be due to a number of different things.

I'll get the device serviced and mention the specific fault to the engineer.

 

[nickso]

Do any BG engineers have any comments to make about this?

yes.

 

[petit_pablo]

Do any BG engineers have any comments to make about this?


Tony

Happens ooccasionally. The best ones are the fixed price repairs. We fix 1 fault then cust rings up again claiming its still faulty and wont pay another fee when in fact there are 2 faults and the 1st engineer didnt spot it

 

[cowboy_diy]

Hello all useful people,

Long shot as this thread is 6 yrs old, I'm facing exactly the same problem as described above at my new place.

It's Worcester Bosch 28cdi combi boiler,
Service was done 2 yrs ago.

I'm planning to get the service done as a first thing, but I would really appreciate if anyone can give me any sort of advice.

If the awesome person who initially started the thread gets this msg, I would be truly grateful if you could reply with what you did and how you fixed it.

Thanks a lot.

 

[JBR]

Of course the reality is a little different ! Boilers are not quite so simple and a single fault like an ignition lockout can be caused by many different reasons as indicated above.

I'm sure you're right.
We have a 28CDi that suffered from repeated ignition lockouts for a long time.
Fortunately, we have a maintenance and repair contract, so called out the engineer whenever the problem occurred. He made all sorts of attempts to overcome the problem (at no extra charge of course) and it now seems to be a thing of the past (touch wood).
So in my experience ignition lockout can indeed have many different causes.

 

[ollski]

If its definitely flashing ignition lockout and its th original gas valve with the 3 connectors on the back Id probably be starting there.

 

[cowboy_diy]

Thanks All.

Ollski, Is it a DIY thing to replace the gas valve? I'm not a boiler expert but I do quite a lot of diy.

Please can someone also point me to some help in terms of how to replace the flame sensing electrode. The manual doesn't have anything in this regard.

Thanks.