Vaillant TURBOmax Plus 824E diverter valve problem?

[mdurkin]

Hi All,
My diverter valve seems to be getting stuck. Sometimes it sticks on heating, other times hot water. It seems to be worse if the boiler is up to temperature (hot).
I have had the motor off the valve, and can see that the motor is operating and pulling the pin (which connects to the valve) in and out. With the motor disconnected from the valve the operation of the motor seems a lot quieter than when it's on the valve and trying to move the valve.
I live in a very (very) hard water area. Is it possible that the inside of the valve is covered in limescale and preventing the motor from moving the valve properly, or could the motor be worn out?
Alternatively, could the drive circuit that drives the motor be the problem (please no!)?
If anyone has come across this problem previously I'd be really glad to hear from you!
Thanks,
Matt

 

[mdurkin]

sorry - should have searched forum a bit better. Now found several posts that seem to point to the divertor valve. Have ordered a replacement from ebay (abouy half the price of anywhere else I could find). Will have a go next weekend.

Anyone know if it's easy to change?
Isolate system, drain boiler, and then how easy to get it off? It's pretty accessible, but I'm not sure how easy it will be to get off. I guess I'll find out next weekend...
If anyone has any tips, let me know!
Thanks,
Matt

 

[bobw1956]

When it's failed again in a few months,you will ask your self is buying off ebay the right thing to do,are u sure you are getting the upgraded D/V

 

[namsag]

Just turn boiler isolating valves off and empty boiler this can be done into a basin when undoing one of divertor connections. No more than a ten minute job

 

[Agile]

The original design which fails has small holes round the motor shaft of about 4 mm.

The later design has holes about 5.5 mm and rarely fails.

There were a few with larger holes with the original internals with a circular ball which fails. The new design has a rugby shaped ball and rarely fails.

Tony

 

[mdurkin]

long overdue response!
The replacement was a genuine vaillant part - it's been in nearly a year now with no problems. I'm not sure what size the holes were or the shape of the ball - hopefully I got the updated model.
As for fitting - 10 minutes was a bit optimistic! It probably took me an hour, though I did leave the boiler draing while I did something else. And it was an easy job - very accessible as it's right at the front of the boiler.