Vaillant TURBOmax VUW 282/1E Hot Water Problem on demand

Guys,
Please can you assist.
My brother inlaw has boiler prob where hot water demand is intermittent and/or not hot.
Has had the diverter valve replaced and this seemed to work for a short period.
next to the diverter valve is a unit with an arm which goes to a micro switch, I believe that this is the switch for hot water demand, and could be causing the problem.
he tells me that if he releases the screw holding this unit and realigns the unit then it will work for a short time again.
I think it possible that this unit is moving due to the screw working itself loose from the function of the hot water demand and needs a spring washer under the screw holding the unit from the picture he sent me.
His plumber (friend of the family) has advised him it going to cost in the region of £150 to £200 to fix???
I have little faith as this fault shoud have been sorted out by him a long time ago.
I myself am a aircraft engineer, and am sure with a little advice I can correct this problem at little cost. As I have on several occassions with my boiler as long as the gas is not affected.
Problem is I have no manual to refer to either for spare parts.
unfortunately having trouble attaching a photo at the moment!
cheers
rik [/img]

Hello Guys,
Since posting the first message I now have a copy of the manual.
All I require is some decent advice please.
Having looked at my bro inlaws photo in detail i'm not really sure if the diverter has been replaced as I'd expect to be looking at a new unit not one that looks like its been there over 10 years. I've asked my bro inlaw to check and find out what he actually did for £200 previously. I think he could be pulling a fast one myself and am waiting to hear back.

regards,
rik

Rotate the switch fully clockwise and secure with the screw. They don't normally come loose unless the threads been damaged.

Have you checked the microswitch contacts with a multimeter?

Does the DHW Led on the front come on each time with a DHW demand?

That diverter looks old...corrosion over the screws etc. Perhaps it was just the diaphragm that was replaced.

If it's a diverter issue, then on a boiler that old I would replace the whole part. Often the seals can fail in the top part of the diverter (leaks) or the plastic arm can fail causing sluggish operation on the microswitch.


Diverter is around the £100 mark for a genuine one. Also replace the auto air vent and re-charge the expansion vessel. If it's done properly with the required safety checks etc £200 is a bargain. Generally a straightforward job but not always. Getting the pipework off on the RHS can sometimes mean cutting out the PRV pipework, the pump plate screw can shear off, the differential switch assembly pipes can block on the boiler drain down and you don't get all the seals with the new diverter.

Think you're mad to get involved

Err £100 is trade price plus vat retail £180 + vat an u do get all seals and all the screws except the one holding the plate! What pipework do u need to remove on rhs Prob fitted a diaphragm kit for that price I think?

Plenty of ebay spares merchants sealing diverters at sensible prices, paid less than £60 at times from traders selling off surplus stock.

Genuine diverter kit does NOT come with all the seals. AFAIR you only get 2 or 3. No pump O rings for example.

Depending on how the PRV pipework is fitted I've have in the past found it imposible to remove the cold inlet (the one with the plastic bow clip) without cutting the PRV outlet pipework and rotating the PRV for clearance.

hi gas guru for ur info the 011289 comes with 2 pump o rings and the fibre washers now since nov 2010 and y remove the bow? u undo the 30mm nut on the cold inlet remove the valve then remove the bow and the pipe... never seenn anyone remove bow in situ

Hey guys,
Thanks for your imput, I think we are waiting to hear back from the plumber to see what he actually did, and then go from there.

Cheers,
rik