VCW Sine 18 T3

[Agile]

Its difficult to give you advice because you dont recognise what the various parts of the boiler do and how they interrelate.

The DHW flow switch powers the boiler and the wax diverter responds to the cold water flow and diverts the heat to the calorifier.

I still think the system flow switch retracts the pin to enable the gas valve and no one else has commented on that. My test example is difficult for me to access at the moment.

Tony

 

[al-yeti]

maybe we just confused what retracts means, when the pin comes out that is opposite to retract, but in the case of the gas valve where the pin is out it retracts to enable gas, so depending on which pin we talk about , the diff vavle comes out the gas valve retracts.

 

[Agile]

No, we are using the same terminology.

Its just that I remember the flow switch retracting to enable the gas valve. Perhaps I am remembering wrongly but its a pity no one else seems to be able to remember either.

Supose you removed the flow switch so the gas valve pin is not touching it? Would it pass gas then or not?

Tony

 

[al-yeti]

nah you have to press the gas pin in to get gas, this is the hole problem you can see the diff valve pin come out on demand but not fully as if theres not enough pressure to push one pin on to other.


I found it strange also that when the pin is fully out i could manaually push pin on diff valve by hand back in, but when working correctly this should not be the case , it should be that there is enough pressure to keep the pin from retracting.

Also i can see no movment on the flow switch on the far left, cant see the levers lift at all in any mode, so am wondering if what our man said the wax stat is faulty and is not providing circulation through DH system on demand.


Or maybe the venturi? or pump , but pump seemed fine when i take screw off front i can see it spinning like mad, with a little water trickle out but that didnt make sense? should there be any water through that point or lots?


Yeti

 

[Agile]

OK then I have remembered wrongly but thats of little consequence as the system flow switch is not working.

Have you checked for water coming out of both bundy tubes when the diaphragm unit is removed?

On some models there is a restrictor in one of the tube connectors at the opposite end.

And as advised your diverter valve is failed, either jammed or the wax element has failed or both!

Tony

 

[al-yeti]

I agree, good thinking i shall look at both pipes, make sure it squirts both ends.


As for the flow switch unit, i cant see anywhere any repair kits for it????

looked at mjt couldnt see anything for it except the to switches that sit on top them selves, apart from that they sell the whole unit....................

anyhow shall check the pipes and get back to you........ getting closer and closer to calling mr corgi!

 

[Agile]

As for the flow switch unit, i cant see anywhere any repair kits for it????

Its not surprising! As they are only about £24 each no one else would ever consider repairing them!

Replace!

Tony

 

[ChrisR]

but pump seemed fine when i take screw off front i can see it spinning like mad

Tells you nothing.
Like I said, you have to take the head off the thing and see how hard it is to stop, or if the vanes are completely clogged.
Don't you thing we know about the screw on the front?

 

[Agile]

It always amazes me how Chris can clean just half of the impeller so well.

Pity he has lost interest in the other half.

Tony

 

[Dan Robinson]

Good picture though!

 

[al-yeti]

Yes ok take the head off i will.


Agile??? what you mean £24??? i was talking about the hole unit which costs about £124+vat (flow switch is on top they r cheap) i on about the main unit which incorporates the wax element, CH and DHW (diverter valve).


£24 are for the switchs only, but the plunger on top is not moving at all when you turn the tap or turn on CH, seems to be stuck down.

Off to check pump and pipes , hmmm 22.14 here i going anyway!


Yeti

 

[Agile]

"hole unit" ?

When I mention the system flow switch I mean the part that enables the gas valve.

You are talking about the diverter valve. You can still get the wax element and its about £26 +vat. It might just be jammed though.

About 40% I see are jammed and 60% wax stat and some both together.

Tony

 

[al-yeti]

as i said before that part is working which is directly below the gas valve, has five pipes going into it

 

[Agile]

as i said before that part is working which is directly below the gas valve, has five pipes going into it

Thats the DHW flow switch! I thought you implied it was not activating the microswitches at the base of the diecast PCB box ?

Tony

 

[al-yeti]

Nope i hope i didnt, i'm sure in previous part of this thread i said its fine, as i can here the micro switch operate.


Anyhow i have taken the pump head off, and it was nice and clean and turns by hand nicely to.



I also checked the flow switch mechanism and noticed when drawing hot water the switch switch isnt fully depressed. so i will adjust this today if i can.


Both pipes going to the diff valve have water coming through them.


If both pipes have water , then what would be stopping full pressure building up to retract the gas pin???? this bit is confusing me!!!!!!!!!!!!