Vaillant 824E mind of its own

[deandoodles]

We mved into this house around christamas 2006 and already installed was (according to the log book) a vaillant 824E combi boiler. We have had no problems with this boiler until very recently. In the past few weeks the radiators have been getting hot when the heating is switched off and the hot water has sometimes taken a required us to turn the tap on full then off again two or three times before it comes out hot. The problem is im kind of cluless here abou the boiler we have the installation documents which tbh are double dutch to me and the log book that says it was installed in 2002. Im asking for any ideas here because we'e utterly broke after buying the house and dont really want to be paying for an engineer to come out to do a job when i wouldnt have a clue what he was doing.
Any ideas much appreciated

 

[chrishutt]

Sounds like the diverter valve. Look for your symptoms in the fault finding section at the back of the manual and also "changing the diverter valve" in the servicing section.

 

[gas4you]

Agree with chris, dv sounds stuck, especially if it is a turbomax rather than an ecomax.

 

[deandoodles]

Cheers guys, anyone a rough idea what this will cost me to get fitted?