I have a Worcester greenstar 25/30si when i run the hot water it all works fine, then after about 5 mins the flame and then the fan cut out, causing the water to run cold, then after about 5 mins it all comes on and fires up again, and keeps doing this until the tap is turned off

stephen, February 2011

I'm no heating engineer but i have a ravenheat that did the same last year. someone told me to clean out the heat exchanger, i took it off and it had quite a lot of particles in it as we live in hard water area. i gave it a good clean out using a hose pipe flushing it back and forth, put it back on the boiler and was surprised to find it worked. i got absolutely soaked taking it off and found it hard to get to the nuts to get it out.

rocker666, February 2011