I'm sick of repairing this TurboMax. First, a history of problems.

The diverter valve, then a switch on the board, then the fan, now back at the diverter valve with lots of other problems developing along the way; e.g. the fill loop has been continually bleeding into the system due to a faulty fill tap, which kept it constantly at maximum pressure. When disconnected, pressure would fall over a week or two to nothing. The system drain valve was malfunctioning so I had to try draining it all through the radiators to repair it. Then the shutoff valve for the direct water had siezed shut (I'd snap it trying to open it) so I had to shutoff the water to the house and install a ball valve in the direct water line to replace the one in the boiler. Water was going everywhere in the meantime. There is a constant list of issues to fix with this thing, more than I've listed here, I hate it.

This time, I was getting the symptoms of diverter valve failure. Water out the taps but it's always cold, boiler doesn't ignite to heat tap water but it will run the radiators etc... Looking into the boiler, I found the microswitch on the valve wasn't operating. If I push it down with the tip of a screwdriver, the boiler would fire up to heat the tap water.

I stripped the diverter valve out and took it apart to replace the diaphragm. It was a bit messed up looking and there was a bit of limescale in there, but nothing serious, like a few grains of sand on the inside. Scrubbed it all clean, but it back together. On replacing the microswitch, I can see the valve stem is no longer tripping the switch when it moves. The tiny plastic arm with the brass bit on it, that goes between the stems and moves, pressing on the switch, has snapped. It's snapped right along the thinner section where the brass tip is, furthest from the switch.

There's no way I can glue that and expect it to last. I could try filing a replacement out of brass or plastic, but that'll be incredibly annoying. Is there a rebuild kit that would have one of these plastic arms in it? It doesn't come with the diaphragm kit but I thought there might be another with it.

Will have to buy a full diverter valve if not and those things, as with everything on the boiler, cost a fortune. Due to the constant fall in pressure and no signs of leaks, I also suspect something like the DHW may need replacing, which could mean a few hundred in total. At that point, having just replaced the fan for around 140, it makes me think it may be time for a new boiler.

Thanks!

John

John, April 2009

My heating comes on when it wants, the thermostat removed, heating dial at fully counter clock position, timer off, but it still comes on when it wants, help appreciated. Ivor

Grumpy Ivor, September 2017

seriously get a new boiler and stop wasting your time throwing good money after bad, and while your at it get a power flush done, 90% of hydrolic faults can be directly linked to system water condition ie sludge/scale
however this boiler has a long history of the fault you describe and there is no answer to it , just bad design fault.

jeff, February 2012

you can but the replacement plastic arm either sepretly or as part of the service kit.

bob, October 2009

Just fitted a diverter valve which I bought on ebay for £57.50 inc postage, on a vaillant turbomax. Took about an hour and the valve is a re-con unit. No probs and the d.v. is good. Result!

morg, May 2009

I have exactly the same problem and was planning to change the switch which I thought wasn't operating properly. The nearside end of the lever pivot shows no sign of a crack.
Is it possible to remove the lever without a major stripdown of the diverter valve?

Cheers,

Nick, May 2009

If you haven't already purchased the repair kit 140352 it does come with the plastic arm with the brass bit on the end, I have a spare one from a Turbomax vuw 242e repair that I did recently that you can have for the cost of the return postage.
Ray the Plumber Bristol.01179568764

Ray Hall, May 2009

As far as i know the only way to get the plastic arm is with this kit.

andy gas man, April 2009

Hi John! Wow, sounds like a hell of a time you've had with that thing.... There is a service kit for that diverter valve that includes everything you will need to fully refurbish it, it's basically everything except the brass bodies. The part number is 14-0352 (GC 792-627) and it's about £45. It's quite expensive for a service kit but the plastic arm doesn't seem to be available as a seperate part and the diverter valve complete is about £150! Good luck!

Andy gas man, April 2009

Okay, I think I might need the rebuild kit 140352 from vaillant. It's still kind of expensive, does it include the white plastic lever that snaps? Or can I still get that separately? Thanks again, John.

John, April 2009