Leaking Diverter Valve

Hi,

I've got a Worcester Bosch 35CDi II combi boiler and theres a leak coming from the diverter valve. I not sure of the exact location but I'm losing water pressure and I have to fill the boiler daily.

I called a service engineer out but I think he was trying to pull a fast one. He told me that the diverter valve required replacing and I'm also likely to experience heat exchanger problems at a later date and should therefore change the heat exchanger too. Thats when alarms bells were ringing.

I would like to know what the cause of my diverter valve leak and whether I can fix it by replacing just the either/all the rubber o ring's/fibre washers or would I have to change the whole diverter. The diverter valve costs £100 and the washers etc cost a fraction of that.

Your urgent response would be much appreciated.

your service eng was probably right ,
The diverter valve if leaking is a real pain to get at and 99% of heating engineers will replace it along with all the 'o'rings around it rather than fit a service kit (BG eng's are encouraged to fit kits but the majority just change the valve as its easier).
The last one i pulled out took over 3hrs to sort out due to the chassis of the boiler not being mounted square and flat causing lks on the connections which go thru the chassis of the boiler.
With regards to the plate heat exchanger the service guy was probably being cautious ,but as the exchanger needs to be removed anyway its worth changing if its showing scale or clogged up.....

Can confirm that it is easier to change the whole unit than just the diaprhagm (sp).
Had mine done about 3 years ago and the guy said the time taken to clean off the old sealant, make sure the surfaces were true and clean etc was outweighed by the ease of fitting a new diverter, (though that isn't exactly easy either but quicker and more reliable).

Can't comment on the heat exchanger as mine was spotless and didn't need any attention.

I also struggle to insert/remove the key from the filling loop assembly. It gets stuck and takes alot of patience, pulling and turning to remove it. Could this be damaged and require replacing while I change the diverter valve?

I'm attempting to do all this work myself, I've never done this before.

Can I drain the boiler by closing off the cold water supply, opening a hot tap and opening the pressure relief valve. Would that drain the water in and around the diverter valve etc and that there would be no requirement to drain the radiators.

Your help would be appreciated.