Worcester Bosch boiler

10 Jul 2004
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United Kingdom
I have a Worcester Bosch 28CDi RSF boiler. The pressure gauge on the front panel keeps creeping up, even though I haven't had the central heating on for months. The grey filling knob is turned off as tight as it will go, and the bayonet key is removed, but still the problem persists. Any suggestions ????
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have you actually removed the filling loop? (Thing just after the filling knob)
I don't think I have. Can you be more specific ???? Thanks
the filling loop is the silver braided flexible pipe that goes from your cold water supply (main) to your heating system.

as i said its the thing connected to the other end of the grey knob you turned off. I am thinking perhaps although you have turned it off it may still be "dripping" which you will find out if you take it off. I could be wrong. but it is one thing you could eliminate, it is also not supposed to be left connected.

here is a picture of my one.

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Mine doesn't have that - it's plumbed direct into the mains cold water with 15mm copper piping.

That's the trouble with today's new fangled gadgets. At least you could disconnect the filling loop (though few people do). Life was so much less hassle when all you had to do for heating was put a pile of logs in the middle of the room and set light to it. :rolleyes:
28cdi have built in filling arrangement, if the grey filling key has been removed and the pressure keeps going up it will be the water to water heat exchamger which has failed letting mains water pass into the heating system.

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