Dear All
I thought I would write to let you know how my little boiler problem has been resolved. You will recall that I have a Vaillant VCW GB 240H boiler and the dhw wasn't working properly, with a high litreage per minute going through the hot tap and the boiler only firing at full flow, with the result that I could only get lukewarm water and if I turned the tap down significantly the boiler went out.
All has been resolved, thanks to the generous input from you people on this forum! It was indeed the water section diaphragm which was causing my problem. It was perforated and badly distorted. As it was date stamped 1989 it had not done badly! We also change the diverter valve diaphragm (which was ok but date stampted 1994 so needed changing) and gave the boiler a service in accordance with the manual which Vaillant sent me. Now it works perfectly!!!!
Thanks to all but extra special thanks to the following for their insightful contributions: -
Scrufflepeck - your boiler diagnostic skills are peerless!
Horace Gripe - thank you for inventing this wonderful boiler Horace!
Merv the Perv - you are the little Welsh chap who put me in touch with the Great Horace Gripe - thank you for that!
Blather - a superb albeit slightly misguided contibution. I shall however be making good use of the diagnostic methodology that you have pioneered, namely the Naked Hand Method (NHM) and the Head Rest Technique (aka "pipe talking") - they make perfect sense to me. Best wishes Blather and I hope you overcome your psychiatric difficulties!
Thanks also to ChrisR, Werewolf, Agile, et al for your kind suggestions!
Bye everyone!!! See you when my boiler blows up next time!!! Bye!!!!!!!
Yours ever
Grimly Feendish