HELP!!!... Vaillant Combi not working...

[__james_]

Hi ppl!

Again I have more problems with my Vaillant Combi heater (VCW 20/1 T3WH).

It has recently had a new PCB and a new Expansion Vessel fitted, which made the boiler work absolutely fine for 2 days, but now all of a sudden it simply will not work! When I turn the hot water and/or the CH on you can no longer hear any clicks and there is no ignition!

I called back the boiler man who fitted the PCB/expansion vessel and he was not too sure on what was wrong and said he will try and look into it.

He did say the pump is getting no power and that for some reason the 3amp fuse on the wall blew rather than the internal 1.6 amp fuses on the PCB.


Has anyone got any ideas as to what the problem could be?!


Thank you very much!

Regards,
James

 

[Agile]

Well I have no idea whats wrong and it would need a proper diagnosis on site.

Since the pump is not getting power and its blowing fuses then the most likely cause is a faulty pump.

Powering the pump from an external source would normally keep it working in the interim and proove if its that at fault.

They are quite expensive as you have to buy the whole assembly so start saving up!

Tony

 

[__james_]

ok thanks for your advice tony!

basically I will be calling back the boiler man later today to see if he got any information from vaillant about the problem!

So in the mean time I am trying to gather as much useful information as possible, and then pass it on to him in the hope that it can help him!


I understand my problem must seam a bit vague without being able to look at my combi, but still, every little helps i guess!


Any more advice ppl?!


Thank you!!!

James

 

[tryitandsee]

The engineer may have accidently spilt water on the pump electrics when draining down etc. to change pressure vessel!

Maybe it just needs drying out and having another go when dry.

Just a thought.

 

[__james_]

i think i have found the problem!


last night i had another look at it myself, i checked the fuse on the other PCB to check it hadn't blown and i also had a look at the overheat reset switch, which seamed to be bent out of place so to speak!

so i tried to push it back out of the hole and i had play with it, flicked it a few times, then i pushed the green igniter button a couple of times and hey presto the boiler worked last night!


however this morning it didn't! so today i did the same again and it worked. It seams when i turn the CH off for a period it cannot reignite itself when i try and turn it back on, unless i play with the overheat reset switch and the green igniter button!!!

therefore i assume the problem is down to either the overheat switch or the green igniter button?!


Any ideas?!

Is it more likely to be the overheat reset switch?!


thanks again!

James

 

[ChrisR]

Well a faulty igniter button is hardly likely to make the pilot go out or the boiler not work...

 

[__james_]

the pilot light hasn't gone out (it stays light unless i press the red button!)

and surely if the boiler cannot ignite it wont work?!


i dont know... just speaking aloud!

 

[Agile]

Well a faulty igniter button is hardly likely to make the pilot go out or the boiler not work...

I think that there is an aux contact on the green button which is in series with part of the boiler circuit because the magneto coil is not part of any gas valve in this boiler.

Carefully open the bit behind the green button and identify and clean the aux contact. Then it will work fine!

Tony

 

[ChrisR]

This is the igniter button. Colours can vary. You only need it if the boiler needs igniting. If you have a flame, it doesn't!

The green square button doesn't do any igniting, but does have contacts...

 

[Agile]

That spark generator is always grey on the boilers I have seen and I think he is refering to the real green button on the magnetovalve with the red one beside it.

Tony

 

[__james_]

That spark generator is always grey on the boilers I have seen and I think he is refering to the real green button on the magnetovalve with the red one beside it.

Tony

yes i am refering to the green button next to the red button!

my combi does NOT have a spark button for the pilot light! (i have to use a match and hold in the green button to light the pilot!)

I think that there is an aux contact on the green button which is in series with part of the boiler circuit because the magneto coil is not part of any gas valve in this boiler.

Carefully open the bit behind the green button and identify and clean the aux contact. Then it will work fine!

Tony

ok cheers Tony! I will give this a try in a bit! fingers crossed!

 

[__james_]

I think that there is an aux contact on the green button which is in series with part of the boiler circuit because the magneto coil is not part of any gas valve in this boiler.

Carefully open the bit behind the green button and identify and clean the aux contact. Then it will work fine!

Tony

Hi Tony, yesterday i took the front of the control box off and took the front PCB out to gain access to the green button etc.

but access was still very hard as i did not want to undo the metal tubes that go to the top pf this area...

so i did my best from looking underneath it to clean it... to be honest i couldn't really do much apart from give it a blow and get my finger in there to give it a wiggle about sort of thing... i know this sounds like a crap attempt but still!

anyway, i put it back together and for the rest of the day it was absolutely fine, and i assumed i had fixed it!

BUT YET AGAIN, this morning when i turned the CH on, nothing... i had to push the green button about 4 times before the boiler ignited and worked!

it seams once i manually get it working via the green button its ok for the rest of the day until the CH is turned off for a period of time (ie. over night!)



can you give me more help on how exactly to remove this part and clean it properly?!


thanks again!

James

 

[the plumbing miracle]

get a new enviromentally friendly condensing boiler you cheap skate

 

[__james_]

help anyone?! (re my last post!)


cheers

 

[__james_]

ttt