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Worcester 24CDi Combi Boiler problems

Postby DJM » Fri Feb 27, 2009 10:46 pm


My boiler has stopped working completely and when turned on the hot water demand indicator flashes on and off very fast. I downloaded the original manual and it says the following if that light flashes 5 times a second:

"Air flow fault (RSF). Flue gas spillage"

then as an explanation it says the following:


The appliance will enter a lockout condition in the event of an
air flow fault.
If the controls fail to detect the correct air flow through the
appliance the electricity supply to the gas valve will be interrupted.
If an air flow fault has occurred, the domestic water demand
indicator will flash (approximately five times per second).
The appliance will try to re-light after a waiting period of
approximately 4 minutes Check that the flue terminal has not been
obstructed or damaged. If this condition continues to occur, then call
a service engineer.


The appliance is fitted with a device which detects the spillage
of combustion products from the draught diverter. In the event of the
flue becoming wholly or partly blocked this device will cut the gas
supply to the burner. If the device has activated, the D.H.W. demand
indicator will flash (approximately 5 times per second).
The device automatically resets after a waiting period of approximately
20 minutes. If the blockage remains the appliance will re-light
briefly before the device operates again. Should the problem persist
consult your service engineer[/i]."

I would really appreciate it if someone could explain the above in laymans terms and let me know whether this is a problem that i could solve myself and if so, would I need to buy any parts etc - or should I bite the bullet and call a repairman in.

Thanks for any help
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Postby kbrownie » Sat Feb 28, 2009 5:35 pm

I,d recommend gas engineer is called, but I won't pretend to know too much. I have a boiler quite like this and if the water pressures is not at right level and air locks in system, won't fire up it tries but in vain.
I do think your post may be better placed on the central heating and air ventalation forum. If you lucky The htg engineer or steve the gas may be able to help. Lots more knowledge available to you on that forum.
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Postby Steve the gas » Sun Mar 01, 2009 7:10 am


Quick answer is - you need an RGI 'cos the problem looks like it is to do with combustion - this is only RGI territory!!

Secondly, which 24CDi have you got (RSF= Room Sealed Flue or OF = Open flued?)
These are quite different, in that 1 IMO is more potentially dangerous than the other. Or 1 can kill you easier than the other, but don't have nightmares- get an RGI in, a good one.

Steve the gas
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Postby DJM » Mon Mar 02, 2009 6:55 pm

Thanks for the reply - I will get a RGI in :)
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Postby TheDoctor4 » Thu Jun 24, 2010 9:00 pm

If you would like to find a reliable, insured and vetted tradesman in your area why not click through to the Find a Tradesman area of DIY Doctor: , complete the form and receive up to 5 FREE quotes
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