Vaillant Turbomax VUW GB 242 E - no hot water?

[Suffolk]

CH works fine. DHW works when CH is on. No DHW when CH is off.

White rocker arm isn't pushing down the microswitch when DHW is called for. Diaphragm looks fine but I've replaced it anyway to rule that out but still the rocker arm won't budge.

If I have the water section open I can push up on the "plunger" (the flat plastic disc with the thin metal rod sticking out of it) that the diaphragm would normally operate but this too doesn't move the white rocker arm.

Any ideas as to where the fault lies? Is it time for a new diverter valve?

Help greatly appreciated.


Cheers

Rich

 

[chrishutt]

New diverter valve unless you like fiddling around with the bits of the old one. Rocker arms break and seals leak.

 

[Suffolk]

Chris

Thanks for the superfast response.

So, a new DV as I feared. When you say "unless you like fiddling around with the bits of the old one" that kind of implies it's repairable - any chance it could be as simple as the other end of the rocker arm having snapped off & it's a 95p job not a 95 quid job? (I know, Murphy's Law dictates it will always be the more expensive solution......)

Thanks again

Rich

 

[chrishutt]

Take it apart and see what's wrong, if you think you're up to it. New bits might be around £20 instead of maybe £200 to have a new diverter fitted professionally.

 

[Suffolk]

Good news.....

Have stripped down diverter valve and yep, the internal end of the rocker switch has snapped off. Amazingly, it's made from nylon/plastic a few millimetres thick except at the bit where it snapped which must be measured in nanometres. Crazy.

Anyway, can get one from local Parts Centre for the princely sum of £1.50. Only down side is they close before I can get there so I'll have to re-assemble everything tonight so we can use the boiler & then do the whole job again tomorrow. Bah!

Still, £200 saved is not to be sniffed at. Well, £198.50 to be precise.

Thanks for your input.


Cheers

Rich

 

[chrishutt]

Replace any other wearing parts while you're at it - the diaphragm, O ring seals, etc. If you include an email address in your profile I could send you a PDF of the diverter valve.

 

[Suffolk]

Cheers - I've done that.

I've set up a hotmail email address - [email protected]

Snappy, huh?

I'll replace all those things whilst I have it apart. Also need to replace the pump bracket of all things because the thread for the top pump mounting screw hole is shot.

I've reassembled it for tonight so we have use of the boiler but I've got a couple of weeping leaks, particularly from the top union. Not a problem for overnight but obviously I need to sort permanently. Do I need to ptfe the union threads or are the fibre washers sufficient?

Thanks for the help - much appreciated.


Cheers

Rich

 

[chrishutt]

Cheers - I've done that. I've set up a hotmail email address

You're not supposed to post email addresses on here, only in your profile, like I said! (Why can't people follow simple instructions?) The mods will take it out pretty quickly if they're on the ball tonight. Anyway I sent the PDF.

 

[Suffolk]

Apologies - my mistake.

I'd assumed the email address is my profile would be as visible as in a post so it never occurred to me it would be a problem. On the upside I'll not be using the email address for anything else.

Thanks again.

 

[Suffolk]

Progress report.....

Thought you might like to know I've done the job now. Replaced the rocker arm & serviced the rest of the parts liable to wear. Reassembled. Took it all apart again to refit the new rocker arm the right way up (durr!). Everything now working perfectly.

Even managed to resolved a long-standing weeping leak on one of the unions to the DHW heat exchanger.

The missus now thinks I'm a CH god. I know, it won't get me far in life but hey-ho. I'll exploit the goodwill while it lasts!


Cheers

Rich

 

[chrishutt]

The missus now thinks I'm a CH god.

It won't last so make the most of it. But, who knows, the boiler might break down again one day and after a few days with no hot water ... you could be the CH god again .