Vaillant TURBOmax VUW 242 - Multiple problems!

[gbvaliant]

I have a Vaillant TURBOmax VUW 242 combi boiler - approx age 10 years old.

In the past few months we have noticed when having a shower that the boiler will kick in and out at random; sometimes when water is being drawn elsewhere in the system (e.g. tap, dishwasher, washing machine etc.) or, more often, when there is no other demand on the system. I have cleaned the shower head and removed a flow restrictor on the shower which worked for a short period, but the issue returned. When the water goes cold, there is a noticeable drop in flow on the shower.

My gut feeling based on research here is that the diverter valve is faulty. Any comments or agreement on my conclusion?

Also, we noticed a blown radiator in our system last week - when I checked the Bar reading, it was at 3 bar and it was clear outside that the pressure release valve had kicked in and water was leaving the boiler via the overflow. Having reduced the pressure at the system release valve, the pressure only seems to increase when the central heating is on.

Again, based on research on this forum this seems to suggest that either the cold feed loop is leaking or that Heat Exchanger may be leaking. Given that a new loop was fitted in the last two years it would be unlikely that this has gone, and given the age of the boiler, it seems the heat exchanger is more the likely suspect. Again, any comments or agreement?

Finally, online prices seem to suggest a diverter valve and heat exchangers are in the range of £70 ea. How much should I expect to pay for labour?

Thanks in advance - would like to get this sorted before Baby No. 2 arrives in the next few weeks!!

 

[Tibbot]

Your diagnosis is almost certainly wrong on both counts.

Worse is the route you're choosing to resolve them. Eg. Trying to fault find by web, purchase the parts yourself and employing a mug (and make no mistake you'll only get a mug) who is prepared to be led by you.

If you can't repair it yourself you will save money employing a competent person at their rates.

 

[Whitespirit66]

Re. the pressure problem, from the age of your boiler, the diaphragm could be ruptured, or just need charging. Reach down the back of your boiler from above, and unscrew the cap arrowed in the picture from the expansion vessel. Making sure the boiler pressure is at 1 Bar, press the pin in the valve. If water comes out, new vessel time. If no water, then check pressure and repressurise vessel as in FAQs.

Untitled

• Whitespirit66
• 17 Apr 2012
• 3

Does the hot water run hot and cold on other hot taps or just shower?

The test above for the expansion vessel is just to give you an indication, you will need an engineer to diagnose and fix your boiler properly.

 

[gbvaliant]

Your diagnosis is almost certainly wrong on both counts.

Worse is the route you're choosing to resolve them. Eg. Trying to fault find by web, purchase the parts yourself and employing a mug (and make no mistake you'll only get a mug) who is prepared to be led by you.

If you can't repair it yourself you will save money employing a competent person at their rates.

That's why I'm checking here! I'm not looking to do the repair myself; I just want to make sure my diagnosis is correct so I don't end up paying for parts which may not solve the problems.

 

[gbvaliant]

Does the hot water run hot and cold on other hot taps or just shower?

Just the shower. I was contemplating changing the Mira shower cartridge, which is 5 years old and could be scaled up I suppose, restricting flow and fooling the boiler diverter valve that the flow is stopping.

 

[Whitespirit66]

Does the hot water run hot and cold on other hot taps or just shower?

Just the shower. I was contemplating changing the Mira shower cartridge, which is 5 years old and could be scaled up I suppose, restricting flow and fooling the boiler diverter valve that the flow is stopping.

In that case, I would be looking to eliminate the shower before saying it's a boiler fault.

 

[gbvaliant]

Agreed, but it could be an expensive £100 purchase and doesn't solve the problem, compounding what could be an expensive bill....

Doesn't solve the high pressure issue though....that's already cost me £100 for a new radiator.

 

[Tibbot]

I'm not looking to do the repair myself; I just want to make sure my diagnosis is correct so I don't end up paying for parts which may not solve the problems.

There's nothing wrong with doing the repair yourself. If you're not though, and someone else is, how will you end up paying for unnecessary parts?

As I stated before, if you wan't to get a mug to fit what you tell him, you will spend more. It's either DIY or not.

Half & half tend to = f/all in these cases.

 

[Whitespirit66]

Doesn't solve the high pressure issue though....that's already cost me £100 for a new radiator.

3 bar won't 'blow' a good rad. It would have been shot already. That's a red herring.

Have you tried the test in my first post? Getting a good engineer, recommended by friends, family or colleagues will save you money rather than guesswork and long-range diagnosis over the internet.

 

[kevplumb]

i think its a sticky low loss hot water pressure release thats sticking
common fault on these boilers

 

[Bunnyman]

Whitespirit u have said that before about expansion vessels , an I'm afraid it's ******! Vaillants often expel water from the shraeder valve if the vessels are flat, the tanks leak around the seam internally ,when repressured they usually reseal into the seam

 

[kevplumb]

no fun you

jeez we all know what is wrong with it

 

[Agile]

That's why I'm checking here! I'm not looking to do the repair myself; I just want to make sure my diagnosis is correct so I don't end up paying for parts which may not solve the problems.

Dont you realise thats exactly where you are heading?

There is only one way to diagnose boiler faults and thats a competent engineer in front of the boiler.

If you decide to guess whats wrong and buy parts and get a cheap mug to fit then then its most likely that you will end up with changing parts which are not going to fix the fault.

Take the advice! Get an engineer!

Tony Glazier

 

[The831Bunny]

It's a wonder it isn't a P C B

 

[Agile]

I had a call from a lady who worked for the BBC who wanted me to replace the pump on her boiler.

Told her that I needed to diagnose the fault first. She said someone else had diagnosed the pump. I said that if she wanted me to change the pump then I would need paying with cash first and if it was not the problem would not be refunded.

She reluctantly agreed that I diagnose the problem first. That was just as well because it was the PCB at fault! She then apologised!