VALLANT SINE 18 T3 WFH COMBI BOILER

trukkakhan · 30 Oct 2012

Hi all and wondering if someone can help.

The boiler is quite old but has been working OK.

Now the pilot light is on but the CH and instant hot water do not kick in. The water pressure in DCH system had dropped so I refilled upto one bar but no luck.
I did a search and found reference to a "overheat reset " button somewhere inside the rocker switches control box - could someone be more specific as to where it is/what it looks like please.
Another post referred to a spring/microswitch assembly behind the green push button - unfortunately the posters link to pictures and more detail is broken. Perhaps one of you can offer more detail.
Thanks

Agile · 31 Oct 2012

The o/h stat is in a rubber cover on the right and towards the back of the outside of the diecast box which houses the PCB. It needs to be pushed towards the left with a ruler or stick.

Keeping the pressure set right is best achieved by checking it weekly.

Tony

ALEC1 · 31 Oct 2012

if you are going to get this repaired then you need someone who understands this boiler...not many I am afraid...

trukkakhan · 31 Oct 2012

Agile/Tony - Thanks - Just tried the reset switch - sadly no effect. Did it with boiler off then on.
ALEC1 - You are right about that - I wanted to get this winter out of the way and have a new installed after winter.
Anyone have an idea about the mechanism behind the green press switch and which bit effects the two micro switches ?

Alex

trukkakhan · 31 Oct 2012

Hi all again !! and Agile/Tony

I depressed the pin on the gas valve and the boiler fired up for a few seconds , there was a slight banging noise then it stopped.

The pressure gauge went from 1 bar to 2 bar within those three or four seconds - could this be related to the pump maybe not turning on ?
I took the big screw off the end of the pump and used a smaller screwdriver on the inner one - it spun round easily.

Which terminal number within the box on the right should show power to the pump ?If there is no power to that terminal is there a way to connect the pump elsewhere to see if it actually works ?

Does the PCB behind the rocker cover also control power to the pump ?

Am trying to pin down the fault to decide repair or replace now. Local boiler guys not interested in an "old Vaillant Sine 18 " - unless someone here is interested in taking it on. I am in North London , N9

Agile · 31 Oct 2012

From what you have described I would guess there are probably three seperate faults.

All most likely still fixable though!

Is the boiler at 69 ?

Tony

trukkakhan · 1 Nov 2012

Tony

Dont understand the question

Agile · 1 Nov 2012

No. 69 at N9 8HJ

trukkakhan · 1 Nov 2012

Hi Tony,

Yes it is - did you fit it for the Gardier's ages ago ?

Come round for tea and cake and a look

Are you local ?
Alex

ALEC1 · 1 Nov 2012

And his call out

Agile · 1 Nov 2012

Tea and cakes would be nice but I would still have to make a diagnostic charge!

But if you wanted me to come you need to contact me by email or phone according to the details on my profile.

Tony

trukkakhan · 1 Nov 2012

Hi Tony,

No problem - will email you shortly.

Alex

trukkakhan · 2 Nov 2012

Still no further on sorting the Vaillant.

Tony/Agile - used mobile number on your profile this morning - left a message. Also an email . Would like to arrange an appointment.

If I cant get anyone to visit can some one advise how to check if the CH pump is operational ie which terminal number is the feed and/or which terminal can be used instead to run the pump in case the original feed is not live.
Does the CH pump need to run for the boiler to heat the DHW ?

Thanks anyone

Alex

Agile · 2 Nov 2012

I am hoping to come to you soon.

But I thought you were driving your truck this morning so did not want to cause you to have an accident or lose your HGV licence!

Tony

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VALLANT SINE 18 T3 WFH COMBI BOILER

ALEC1

ALEC1

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