Glowworm 15cxi

2 Oct 2010
Reaction score
United Kingdom
I went to look at one on Monday this week (I last serviced it Jan 2009) as the user wanted another service.

When I turned up, the appliance wasn't working atall and upon re-setting I was getting random F codes.

F1, F4, F6 in no particular order. I traced one of the faults to an NTC sensor but was concerned about the heat within the boiler.

I ordered a new sensor and heat exchanger seals but couldn't get back to the property until today as I've been away 1st fixing some bungalows in Kent.

The customer called me last night to tell me he had called in BG as he was desperate (fair enough) and they had fixed the boiler. Total price, £430 something as they do a fixed price repair of £189 but as the repair took over 2 hours the charge was different.

Apparently, the BG Engineer explained that basically I was at fault as I didn't replace all the seals / gaskets on the last service. They were all inspected in Jan 2009 and were fine then, but that was 2 years ago.

Just wondered what any opinions are on this, as I'm sure if I serviced it last year they would have shown signs of wear and I would have replaced them.

Mr. W.
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They were all inspected in Jan 2009 and were fine then, but that was 2 years ago.

Did you fit a new graphite seal or did you leave the old style rubber seal in?
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if you left the old rubber seal in then you were at fault. Ntc has been damaged by the heat escaping from the seal, F1 and F4 prob due to electrode getting coating of crud due to poor combustion also due to seal leaking.
Sorry for the dealy in replying.

Graphite seal was fitted Nov 2007 (along with the heat ex) by the manufacturers. Customer has shown me the receipt for the work done as I've just returned from his house. As far as he is concerned, it should have been changed again in Jan 2009. Are the graphite seals prone to failure now? Looked fine when I last serviced the appliance though.

Mr. W.
I know vaillant want the graphite seal renewed if the combustion chamber is opened for any reason and every five years if not opened, pretty sure glow-worm will be the same.
Well then, I'm at fault. Thanks for all who have contributed.

Mr. W.
I also agree that you are to blame if you opened the CC in 2009 but did not change the seal as advised.

BUT I also consider the customer to be to blame because they did not have the boiler serviced 12 months later.

At that time any slight leakage on the seal would probably have been simply solvable by replacing the seal at that time.

I wonder what took BG two hours? By the way that charge is in excess of what the BG guys on here tell us.


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