temperamental hot water from a Vailant turbomax

[mherson]

Vailant turboMAX plus boiler. Not old, but was largely unused for 2-3 years while the house was empty till I bought it earlier this year. I had it serviced when I got in.

During the summer, when I wasn't using the heating, it was fine providing hot water.

Now the heating's on, heats the rads fine. Very temperamental about providing hot water though. Fires up no problem, but obviously the valve that is meant to open it to heat the water is not switching over consistently.

The current pattern - though it changes sometimes - is that it will only provide hot water while the boiler is lit to heat the rads, and not when the heating has been on for a long time but only when it's been off for some time and then on for less than a hour or two.

Do I :
persevere and hope it improves with use?
get on to Vailant?
put my foot through it in frustration?
find a magic thing to twiddle from someone out there on DIYnot? please!

Cheers
MH

 

[Gasguru]

Turn OFF the boiler.

Unscrew the diverter knurled ring and remove the motor head.

Using long nose pliers check the pin inside the valve body is free to push backwards/forwards with little force.

If not you need a new diverter.

 

[ChrisR]

....and have fun reconnecting the head to the pin!