Vaillant Tuebomax VUW GB 242 /1E

[Peter Saunders]

Hi all,

I have a vaillant Turbomax VUW GB 242 /1E. And it keeps failing the diagnostic panel shows the yellow ignition indicator light flashing. The boiler then won’t work not for heating or water. I have to reset the boiler at the switch and then it fires up as normal runs until the thermostat shuts down the system. When it tries to fire up again it's the yellow light disco again. I replaced the diaphram about eight months ago.

Can anybody help

 

[Agile]

That sounds like a flame failure fault.

Usually fairly simple to identify but its CORGI territory so I cannot give you advice on that.

Tony

 

[Peter Saunders]

Hi Tony,

Corgi territory is a rocky place to tread. But thanks anyway.
I banged about on the net and spoke to Vaillant and with much staring at the boiler everything seamed to point to the Pressure Differential Switch. So I changed it this morning and so far so good. I had a look inside the old one and there was a lot of a redish deposit that must have been causing it to fail. Quite an easy job really Turn the inlet valves of. Take the combustion chamber front of. drain the CH system down and a simple clip held the switch in place. £30.29 in total and a drive to the shop not bad for a Hot shower and a worm house.

Cheers,

Peter

 

[ChrisR]

a worm house

You live in a CAN?

The pressure switch is designed to make the boiler muck about when the pressure gets low. Rather bizarre but well known. Yours was obviously telling the boiler it thought the pressure was low, because of the gunk in it.

 

[bengasman]

a worm house

because of the gunk in it.

that means problems will appear sooner rather than later

 

[Peter Saunders]

Yes sorry about the spelling. That one got past me.
It is nice and warm not underground.


Is it usual for a such a large deposit to build up.

Bengasman. Could you explain the sooner rather than later quote as I am starting to get a bit worried. Should I expect more problems as to this having a knock on effect. Or will it be just the normal stuff.

Peter

 

[bengasman]

Corrosion will effect just about everything in the system. At least, easiyl, half the repairs and replacements I do are down to it.
Rads, valves and primary h/e’s will leak, plate h/e’s and diverters clog up, pumps wear out etc.
More boilers die from corrosion than from old age.
Corrosion is by far my number one money generator.
Lots of people knock powerflushing but is the only way to really clean the system.
That is conditional to using fx2 which some boilers can’t handle, and carried out by someone who knows all the tricks, got all the gear and is willing to do the hard work.
I have the gear, know the tricks, but am not too keen on wearing myself out so charge a fair bit to do it.
Having said that, though not as good, a flush with chemicals is a lot better than nothing and a lot cheaper.

 

[ChrisR]

Can second all of that - except I'm sure I don't know all the tricks!

It's impossible to clean 100%, but it's worth doing something. Law of diminishing returns, as usual. You can undo/take off a small rad to have a look at what your grot situation is. If you've run with a cleaner for a week, then use the connections to do a mains flush(see FAQ) and put decent inhibitor in, you've done all you would normally need, without spending much.
Adding a Magnaclean or Boiler Buddy is one stage more, with the benefit that you can SEE what's going on. (without doing anything, in the case of the B-B)

 

[bengasman]

Can second all of that - except I'm sure I don't know all the tricks!

okay, okay I’ve got orthopaedic shoes.

Most of the tricks including all the important ones??

 

[aris]

I have a similar problem on a TurboMAX 282

Peter, did you notice that the light flashed even when there was no deman for CH or HW? If I switch mine off, and wait almost exactly 5 minutes - I get the flashing light.

If so I might give the pressure differential switch a go!

Aris

 

[aris]

I've got a replacement differential switch now. Is it really necessary to drain the whole CH system down? I see there are two tubes which fit into the back - I assume these just press in and stay there - there are no threads or anything else I can see.

 

[Peter Saunders]

Hi aris,

Hope you have sorted it out already. But if not,
Yes after the demand for water had stoped the light would start flashing and would be constant. only a reset would start the boiler. apparently there is a timing issue also with the switch. If the small white plunger that sits on top of the switch does not fall quickly enought than the system locks up.
Anyway I only needed to drain the internal system of the boiler not the whole thing. Thank god.
I shut all the valves of including the one you cant really see with the white knob on the cold water shut of valve and followed the steps I have mentioned above.
Then unclip the part and replace.

Do you need a PDF manual. I can email it to you if you do 1.173 kb not to big.

Peter