Thats a good question G, maybe I was side tracked with someone's post.
Go to the multi block checks (st16) and check the wires on the right for resistance readings in previous post.
Sorry for mis guiding you, had a long day
Worcester 28 i Junior wont light.
- Thread starter grill
- Start date
Thats a good question G, maybe I was side tracked with someone's post.
Go to the multi block checks (st16) and check the wires on the right for resistance readings in previous post.
Sorry for mis guiding you, had a long day
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Check the pump is set to speed 3, they are often turned down on smaller systems due to noisy rad valves (unless and auto bypass valve is fitted..the boiler one's insufficient). At one time Worcester were saying it's acceptable to set the speed lower but they have contradicted themselves.
However, from what you're saying it's more likely to be an ignition problem.
Check the flue restrictor...the burner has to cross light from one side to the other..excess flue draught could prevent this happening sufficiently quick to prevent lockout.
The MI minimum burner rate is 1.2mbar.....perhaps up to 2 and see how it goes.
However, from what you're saying it's more likely to be an ignition problem.
Check the flue restrictor...the burner has to cross light from one side to the other..excess flue draught could prevent this happening sufficiently quick to prevent lockout.
The MI minimum burner rate is 1.2mbar.....perhaps up to 2 and see how it goes.
Yeah mate i am corgi registered and i should be on the secret list but cant remember my password.
Im still not fully sure about the flue restrictor as this is my first time working on one of these. Are we saying that there is excess draught and not enough gas so it is catching the spark??
P.S. No one is misguiding me. This is the sort of knowledge i crave!!!
Defo think i should try boosting the minimum pressure
G
Im still not fully sure about the flue restrictor as this is my first time working on one of these. Are we saying that there is excess draught and not enough gas so it is catching the spark??
P.S. No one is misguiding me. This is the sort of knowledge i crave!!!
Defo think i should try boosting the minimum pressure
G
The flue restrictor ring is fitted between the combustion chamber and the flue elbow. You can see if it's fitted by looking at the little V cutout. whether it's the correct size is another matter.
The ignition electrodes are left front and the sense back right. The burner has to cross-light across the ribbons...if draught is excessive cross-lighting can be slow. Also the ignition burner pressure is very low so perhaps it's failing to light. These are all the first checks to make before pcbs are considered. I assume you've checked APS contacts etc.
Have you suggested to the owner he turns down the boiler heating temperature setting on the boiler to try and rule out overheating and to feel the flow pipework when it locks out. Have they got TRV's on all the rads? the internel bypass may not cope with this scenario.
The ignition electrodes are left front and the sense back right. The burner has to cross-light across the ribbons...if draught is excessive cross-lighting can be slow. Also the ignition burner pressure is very low so perhaps it's failing to light. These are all the first checks to make before pcbs are considered. I assume you've checked APS contacts etc.
Have you suggested to the owner he turns down the boiler heating temperature setting on the boiler to try and rule out overheating and to feel the flow pipework when it locks out. Have they got TRV's on all the rads? the internel bypass may not cope with this scenario.
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Right i will check out the flue restrictor the next time i go back. Surely this would have been a problem from day one though? This lockout problem has only started happening after a year and a half.
Again APS contacts should be fine as the burner ran fine for 4 hrs today.
Im still curious as to why this has happened when he turned the thermostat down!!! May just be conicidence. This is part of the reason why i dont suspect overheat.
Will check TRVs as well when next there.
The joys the joys!!!!
G
Again APS contacts should be fine as the burner ran fine for 4 hrs today.
Im still curious as to why this has happened when he turned the thermostat down!!! May just be conicidence. This is part of the reason why i dont suspect overheat.
Will check TRVs as well when next there.
The joys the joys!!!!
G
You're making far too many assumptions; for successful boiler repairs don't assume anything..test and verify.
Test APS contact ohms and operating pressure.
Regarding flue restrictors..I've encountered many boilers that not been fitted with the correct restrictor and have run for years without a problem..then one day they start to lockout. Conversely there are also boilers that require the ring to be taken out after a few years due to the manufacturers not allowing boiler ageing.
Perhaps if the room stat is turned down the boiler will not be firing up so many times so less opertunity for lockout.
Test APS contact ohms and operating pressure.
Regarding flue restrictors..I've encountered many boilers that not been fitted with the correct restrictor and have run for years without a problem..then one day they start to lockout. Conversely there are also boilers that require the ring to be taken out after a few years due to the manufacturers not allowing boiler ageing.
Perhaps if the room stat is turned down the boiler will not be firing up so many times so less opertunity for lockout.
Update,
When i got out to the boiler again i turned it on and it went through the run sequence and got to ignition stage but i didnt have any spark at the electrodes.
I turned it off and on again and this time i has a spark and it lit. Checked everything else you said and it all was fine.
So it appears we now have a sparking problem. The manual says to change PCB. Is it not just possible to change the transformer or should i just follow the manual??
G
When i got out to the boiler again i turned it on and it went through the run sequence and got to ignition stage but i didnt have any spark at the electrodes.
I turned it off and on again and this time i has a spark and it lit. Checked everything else you said and it all was fine.
So it appears we now have a sparking problem. The manual says to change PCB. Is it not just possible to change the transformer or should i just follow the manual??
G
Grill, you dont need a password to enter the Combustion Chamber. You just email admin with your CORGI number and postcode.
I certainly dont think that all this information should be on the public forum. All the DIYers will be checking their restrictions and sparks now!
Marvellous Mod 10 should have deleted it before it got this far.
Tony
I certainly dont think that all this information should be on the public forum. All the DIYers will be checking their restrictions and sparks now!
Marvellous Mod 10 should have deleted it before it got this far.
Tony
Yeah i thought about the APS also. I didnt have a chance to test as it works everytime i turned it on and off after i got it going the first time.
It does it on both heat and HW.
Dont know if this make any sense but when it doesnt spark you can hear a series of quick ticks from the board direction!!!
G
It does it on both heat and HW.
Dont know if this make any sense but when it doesnt spark you can hear a series of quick ticks from the board direction!!!
G
Only comment i will make here as i wouldn't want people checking theses and opening upto this degree:
Silly question, but have you checked the electrode leads connecting to the spark electrodes, from the PCB as i was called to one with a slightly damaged lead it would fail for large amounts of time if the board is trying to cause the spark its got to be earthing somewhere and or not completing, you could check continuity from the PCB to the Electrodes, if there is no spark, and the Fan, Flue and APS is ok try this, its one of those things a lot of people seem to check and for a 5 second continuity test its worth a go.
Also if in any real doubt, when at the address get the mobile out and call WB there pretty good actually if your in front of the boiler, you'll need a copy of the manual a good multimeter, Your Corgi Number and a cuppa but they are pretty good if your in front of it
Silly question, but have you checked the electrode leads connecting to the spark electrodes, from the PCB as i was called to one with a slightly damaged lead it would fail for large amounts of time if the board is trying to cause the spark its got to be earthing somewhere and or not completing, you could check continuity from the PCB to the Electrodes, if there is no spark, and the Fan, Flue and APS is ok try this, its one of those things a lot of people seem to check and for a 5 second continuity test its worth a go.
Also if in any real doubt, when at the address get the mobile out and call WB there pretty good actually if your in front of the boiler, you'll need a copy of the manual a good multimeter, Your Corgi Number and a cuppa but they are pretty good if your in front of it
Its a valid point stingray.
The electrodes were the first thing i checked and cleaned and when i do get a spark it is a healthy one. All connection etc appear fine but that is me doing that assumption thing again!!!!!
As for the phoning WB if i had that option i would be elected!!!! I only work on boilers in the evenings and weekends so i dont have that luxury. Hence why im always on here pestering people for info!!!!
G
The electrodes were the first thing i checked and cleaned and when i do get a spark it is a healthy one. All connection etc appear fine but that is me doing that assumption thing again!!!!!
As for the phoning WB if i had that option i would be elected!!!! I only work on boilers in the evenings and weekends so i dont have that luxury. Hence why im always on here pestering people for info!!!!
G
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