Vailant VCW242E "operator" problem

[650max]

Gents

This is my 1st post so please be gentle with me.

Vaillant VCW242E won't ignite, fan runs, diverter operates, pump runs, ignitor can be heard clicking (and seen sparking) and the piston operates on the differential valve (it was a bit dirty inside so cleaned the rust out, diaphragm is fine) and I've got 21v across the 2 wires for the gas operator.

Using this diagnostic http://www.acwilgar.co.uk/Boiler-Ma...t and thermocompact logical fault finding.pdf indicates the operator is at fault so I bought a new one, still no ignition.

I tested the solenoid coil on the new operator which gave infinite resistance, so the new one is defective right? Out of curiosity I removed the 4 retaining screws and eased the operator away from the gas section which allowed me to depress the spring loaded plate and hence the needle with my finger tips, hoping this would allow things to work (just to prove that there wasn't another problem, perhaps diaphragm pump?), still no joy. does the operator have any other function than to move the needle?

It's a given that I need another operator 'cos both old & new are toast, is there something else I should be looking at? Is something blowing the solenoid coil as soon as it powers up? Bearing in mind both the diagnostic and Vaillant handbook say 20v where I've got 21v.

Any help or suggestions gratefully accepted thanks

Max

 

[matt1e]

Gents

This is my 1st post so please be gentle with me.

After reading this I doubt they are going to be

It's a given that I need another operator 'cos both old & new are toast, is there something else I should be looking at?
Any help or suggestions gratefully accepted thanks

Max

Yes yellow pages or google "boiler engineers" for your local area

Matt

 

[650max]

Ahhh, now I undestand how it works (a bit of research) I can understand your concerns Matt.

If I've got this right, the solenoid opens and allows the air pump to operate via the 2 flexibles which supplies a couple of millibar of pressure into the cavity inside the operator which in turn passes through the tiny port into the gas valve and opens the gas supply to burner.

I take it there's insufficient gas supply for initial ignition from the differential valve alone?

 

[Bunnyman]

Eh does it lockout?

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[Agile]

I think that you have come to the wrong conclusion!

The conclusion that I have reached is that you ARE a gas engineer and rather bored so you have concocted this post as a WIND UP.

I would also probably locate you in SW Scotland !

 

[Bunnyman]

Oh oh agile do u know somethin I don't ? That fault chart he's lookin at shows everything except what's wrong with it ! Wasted money on an operator!

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[650max]

Oh oh agile do u know somethin I don't ? That fault chart he's lookin at shows everything except what's wrong with it ! Wasted money on an operator!

Wasted money on an operator that doesn't work! The replacement came from a trade dealer on ebay so he's getting it back, it's just the ball-ache of having to order another and the 2-3 day wait, it's bloody freezing here up north.

 

[Bunnyman]

yes but answer the question mate does it lockout and your miles off with how diaphragm pump etc work

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[650max]

Yeah locks out after about 10secs of igniter firing.

Can you enlighten me on how the pump works? Both the operators I've got are definitely useless, no continuity through the solenoid coil terminals on either so if the solenoid doesn't work then the diaphragm pump can't?

BTW Agile, you're not far off, just the wrong country, I'm about 45 miles south of the wall.

cheers

Max

 

[650max]

Bump anyone while I'm waiting for a replacement operator?

 

[650max]

Well I got the new operator, fitted in 10 mins, bled all radiators, topped up, bled everything again and final top-up to 1.2 bar and... wonderful heat & hot water after nearly 2 weeks without, marvelous!

Max

 

[Bunnyman]

eh they don't come preset mate an the operator sets burner pressure!!

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[650max]

eh they don't come preset mate an the operator sets burner pressure!!

Untitled

• Bunnyman
• 26 Mar 2010
• 499

Yep, I realised that so swapped the front plates over between new & old operator, the adjuster screws on the original are sealed with red paint and also have a cover plate lock-wired in place.

When I can lay my hands on a pressure gauge that reads in millibar then I'll check burner pressure for fine adjustment but for the moment it's working spot-on with no yellow tip to the flames.

 

[Agile]

No yellow tip to the flames!

As all boiler engineers know thats the way to determine if a boiler is operating both safely and at the manufacturer's settings.

All others should realise that its not sensible for a DIYer to try to do repairs involving gas components OR any PCB's which have gas settings on them. Thats probably at least half of them!

Tony