worcester lock out

[algeep]

hi guys hope you can help been looking at a worcester combi 24i when reaching demand goes to lockout and wont refire if you isolate the boiler and turn back on everything works as normal untill demand satisfied again , fan seems fine as does pump and air pressure swith pump and fan overrun as normal if heating turned off and continue when heating called for but demand satisfied just wont refire

 

[algeep]

forgot to add its a 24i rsf and when starting from reset the hot water works fine time and again unitl boiler goes to heating demand satisfied then nothing works cheers

 

[Mr M]

Sounds similar to a problem with a Worcester 24i Junior that my Dad is currently experiencing. Did you ever resolve it ?

 

[bengasman]

be so kind to read:

announcement: read this first.

at top of forum,

and also tell us what setting your boiler stat is on.

 

[bengasman]

be so kind to read:

announcement: read this first.

at top of forum,

and also tell us what setting your boiler stat is on.

 

[Mr M]

be so kind to read:

announcement: read this first.

at top of forum,

and also tell us what setting your boiler stat is on.

The boiler is a Worcester 24i Junior (gas)

When demand for hot water is called, this works fine. Switch over to central heating and it locks-out. The Fault Indicator and Reset button flashes red about 5 times a second and the User Instructions says that this is an Airflow device fault and suggests "Check that the flue terminal has not been obstructed or damaged" I did this, albeit from the external cowel but it looks clear.

I then turned the power supply off, left it a couple of minutes and turned it back on again. The Fault Indicator and Reset button now flashes red about once a second. Pushed it in to reset it but it then, when c/h demand is asked for, it flashes red about 5 times a second again.

Nothing has been done to/changed on the boiler recently.

The problem started earlier today

 

[bengasman]

if i remember this model correctly, the main difference between dhw and ch is that the pump does not run on dhw.
first checks should be:
pump running (sufficiently
blockage
flow sensor (not sure if this model has one)

 

[swbjackson]

It's time to call in the gas man I'm afraid.

Installation manual states that flashing 4 times a second (doesn't list 5) means

CH or DHW Sensor fault or out of position.
Air pressure switch fault or condense in tubes.
Fan fail or stiff.
Blocked flue.
Faulty harness.
Board fault

You'll need to get you friendly local registered gas installer to check for you and hope it's one of the cheaper parts failed.

Mike

 

[swbjackson]

if i remember this model correctly, the main difference between dhw and ch is that the pump does not run on dhw.
first checks should be:
pump running (sufficiently
blockage
flow sensor (not sure if this model has one)

I think your thinking of the i rather than the i junior.

Mike

 

[bengasman]

Am I glad I started off with:
If I remember correctly....

as the boiler works fine on dhw, my first guess would be the last of your options. might be worth checking if all the connectors from the harness are clean and make proper contact though.

Got curious and looked up the manual, and the only 24i junior manual i have shows a bi flow hex. are you sure the pump runs anyway for dhw?
i only ever installed one of these about 4 years ago and promised myself i'd never do it again and can't quite recall from that long ago.

 

[Mr M]

It's time to call in the gas man I'm afraid.

Installation manual states that flashing 4 times a second (doesn't list 5) means

CH or DHW Sensor fault or out of position.
Air pressure switch fault or condense in tubes.
Fan fail or stiff.
Blocked flue.
Faulty harness.
Board fault

You'll need to get you friendly local registered gas installer to check for you and hope it's one of the cheaper parts failed.

Mike

Thanks Mike. Page 11 of the User Instructions here does refer to flashing 5 times a second although it does say approximately

 

[Mr M]

as the boiler works fine on dhw, my first guess would be the last of your options. might be worth checking if all the connectors from the harness are clean and make proper contact though.

Can you tell me what you mean by the harness? I am assuming that this is something I can check myself, or at least get my Dad to check tomorrow

Got curious and looked up the manual, and the only 24i junior manual i have shows a bi flow hex. are you sure the pump runs anyway for dhw?
i only ever installed one of these about 4 years ago and promised myself i'd never do it again and can't quite recall from that long ago.

Is the manual which you are referring to, different to the User Instructions in the link in my post above. If it is, can I get hold of a copy for reference?

 

[bengasman]

service and installation manual aka manufacturers instructions.
installer should have left these with the boiler
harness is the bunch of cables, from the pcb to the rest of the boiler

 

[algeep]

if you ever need any boiler manuals try goto plumbing . com they have everything