Worcester 30CDi over-temperature

29 Sep 2013
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United Kingdom
We have a 6 yo Worcester Bosch Greenstar 30CDi.
Today, when the demand for heating ceased, the temperature on the boiler showed 80°C. When the green 'flame lit' light went out, the temperature started to rise quite rapidly, peaking at 108°C. The figures 108 flashed alternating with a part bracket in the corner (see attached file).
I am going to phone Worcester Bosch in the morning, but would appreciate any guidance.

Do we have a problem?
Is it going to have a long term effect on our boiler?


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Got the exact same problem with mine today, worked fine all morning with the temp in the mid 60s and then suddenly spiked out of control to 100+.

No error codes showing, I tried turning the thermostat down, letting it cool and then turning demand back on, which is when I got the video. Now I've switched it off and will try it again in a couple of hours when it's cooled to under 60.

It's less than two years old but I've been chasing the installer to register the warranty with Worcester, AFAIK currently it doesn't have one.
Thanks, I'm going to give them a call tomorrow, but the warranty issue is a bit of a saga.

It was supposed to have a ten year warranty, but only if registered by the installer. I didn't know until just over a year after installation that it wasn't registered, when I saw my neighbour had received a pile of warranty stuff through the post (he had the same boiler fitted by the same company). I checked with Worcester and they had no record, the installer said "don't worry about it, it's sorted", then I found they'd written the serial number down incorrectly in the commissioning checklist and no doubt tried to register this number and not the actual one. Worcester won't let me register as it's waaaaay after the 30 day since install limit, so I've been hassling the installer periodically when I remember.
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They will honour your boilers minimum guarantee no quibble. A 10 year guarantee has to be fitted by an approved installer so that's something you'd have to speak to Worcester about
t's less than two years old but I've been chasing the installer to register the warranty with Worcester, AFAIK currently it doesn't have one.
in order to maintain the warranty the boiler has to be serviced every 12 months, Worcester will come out and service it and restore the warranty, think its about £120 cant really remember but I arranged this for a customer last year, as others have said worcester are one of the more lenient manus for warranty, so definately worth another call
The Worcester technician came out yesterday. He has recommended that we change the pump setting from the variable power/speed setting to a constant speed. We have done this and it seems to have overcome the problem.
I have also spoken to WB technical support who say that the flashing temp display is due to a too rapid rise in temperature.
Worcester will come out and service it and restore the warranty

Can I still do that if the boiler is non-functional? I came back from a week away and the temp had fallen to 21, switched the heating on and it was at 80+ within 30 seconds, as though it's heating the same bit of water and not circulating anything.
Phone them and ask them just explain the situation, failing that they will do a fixed price repair for £270, just remember they want you as a customer and will want to do something for you

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