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Combi boiler leaking water

Postby LTJ » Fri Jul 20, 2007 8:14 pm


Please can someone advise how serious or otherwise is having water leaking from a combi boiler? I have just discovered this is the last couple of hours and have switched off all electrics going in to it. I can't get an engineer until tomorrow pm.

It's not too much water but I'm looking for some reassurance that this doesn't need seeing to right at this minute (ie I can go to bed without worrying!)

Many thanks

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Simply Build It

Postby htg engineer » Sat Jul 21, 2007 10:42 am

If you cant establish where the water leak is coming from, why don't you turn off the mains cold water supply to the boiler and also there'll be a pressure relief valve, if you turn this all water from the heating side of the boiler will be discharged outside of the house via a copper pipe.

Turning off the water and releasing the presssure, will stop all leaks.

The only problem with leaving the leak, is if its leaking only to electrics, or the gas valve etc, these could be permanently damaged.
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Postby nathan123 » Sat Jul 21, 2007 3:03 pm


ok firstly i am not a plumber and dont pretend to be, and have just come onto the forum for some advice re water in my combi boiler.

Having spoken to my installer he has advised that if rain has got into the flu pipe and a lot of rain then this can be sucked up into the burner which in turn ruins the control unit.

Apparently the control unit is the expensive brains of the combi boiler and a new control unit is between 200-300 pound (ouch). Appears this is what has happened to mine. I have a Grant combi 90 V3 and have been advised to get a new control unit.

My boiler is only 8 months old so you can appreciate how upset i am too.

Im going to aks the question on a new topic about mine, but as long as your boiler is off at the boiler and off at the spur switch then you will be fine until your expert arrives.

Hope this helps you sleep.

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