my vokera excell 80 sp combi boiler causes the water to run hot then cold in roughly minute intervals. the central heating seems to be working fine. the same problem was fixed previously by engineer who simply blew build up of something from small flexi rubber tube inside. note this has not solved the problem this time.
Its a step modulating type boiler ,I think you need modulating boiler to give constant hot water through a shower.
jimbo
December 2007
souns like the flue venturie is blocked remove flue elbow and you can see it looking down from above clean with small screwdriver also clean pipe with rubber tube on it to check that this is the fault opperate with cace front removed and it works fine do not leave like this
john
November 2005
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