Thanks DDK - that was a big help. I've found the website...only problem, do I need a 'blending valve' or a 'mixing valve' or are they the same thing?!!!
Thanks Tony, off to a plumbers merchants this afternoon! Thanks so much for your help and I'll let you know if it worked! Have to get this sorted today, the kids are covered in chocolate and need a warm bath!!!!
Sorry - thought that valve might be part of the pump! I've had a look at the tank and there is a valve on there with MIX written on it. I'm assuming that's the mixing valve. It looks like this:
http://www.advancedwater.co.uk/IMAGES/BRAWA%20MIXING%20VALVE%201.JPG
If I get this replaced, do...
Our radiators are working fine but we haven't been getting any hot water for about a week now...not good for showering! The water is hot for about 30 seconds then starts to run cold. Our boiler seems to be working fine and the hot water tank upstairs seems to be hot. Our house is about 18 years...