[ARWadsworth]

The problem is that when only CH is called the boiler will not switch off
when the programmer switches off. The same happens when both HW and CH are
called for by the programmer and the HW is satisfied before the CH.

The wiring seems to be fine and the mid position valve moves to the correct
position at all times and is correctly controlled by the room stat and the
cylinder stat.

Any ideas.

The only idea that I can come up with is that orange wire (which stays at
90v when there is no power to the valve after calling for CH only) is
somehow tricking the boiler into staying running and I suspect the boiler
PCB is faulty.

Adam

[geoff]

In message ,
ARWadsworth writes
The problem is that when only CH is called the boiler will not switch
off when the programmer switches off. The same happens when both HW and
CH are called for by the programmer and the HW is satisfied before the
CH.

The wiring seems to be fine and the mid position valve moves to the
correct position at all times and is correctly controlled by the room
stat and the cylinder stat.

Any ideas.

The only idea that I can come up with is that orange wire (which stays
at 90v when there is no power to the valve after calling for CH only)
is somehow tricking the boiler into staying running and I suspect the
boiler PCB is faulty.

How long have you been a regular here ?

How many times has someone been called a numpty for not saying what
boiler they have ?

--
geoff

[ARWadsworth]

"geoff" wrote in message
...
In message , ARWadsworth
writes
The problem is that when only CH is called the boiler will not switch off
when the programmer switches off. The same happens when both HW and CH are
called for by the programmer and the HW is satisfied before the CH.

The wiring seems to be fine and the mid position valve moves to the
correct position at all times and is correctly controlled by the room stat
and the cylinder stat.

Any ideas.

The only idea that I can come up with is that orange wire (which stays at
90v when there is no power to the valve after calling for CH only) is
somehow tricking the boiler into staying running and I suspect the boiler
PCB is faulty.

How long have you been a regular here ?

How many times has someone been called a numpty for not saying what boiler
they have ?

--
geoff

Worcester 24Ri

Adam

[geoff]

In message ,
ARWadsworth writes

"geoff" wrote in message
...
In message ,
ARWadsworth writes
The problem is that when only CH is called the boiler will not switch
off when the programmer switches off. The same happens when both HW
and CH are called for by the programmer and the HW is satisfied
before the CH.

The wiring seems to be fine and the mid position valve moves to the
correct position at all times and is correctly controlled by the room
stat and the cylinder stat.

Any ideas.

The only idea that I can come up with is that orange wire (which
stays at 90v when there is no power to the valve after calling for CH
only) is somehow tricking the boiler into staying running and I
suspect the boiler PCB is faulty.

How long have you been a regular here ?

How many times has someone been called a numpty for not saying what
boiler they have ?

-- geoff

Worcester 24Ri

I'll check tomorrow


--
geoff

[ARWadsworth]

"geoff" wrote in message
...
In message , ARWadsworth
writes

"geoff" wrote in message
...
In message ,
ARWadsworth writes
The problem is that when only CH is called the boiler will not switch
off when the programmer switches off. The same happens when both HW and
CH are called for by the programmer and the HW is satisfied before the
CH.

The wiring seems to be fine and the mid position valve moves to the
correct position at all times and is correctly controlled by the room
stat and the cylinder stat.

Any ideas.

The only idea that I can come up with is that orange wire (which stays
at 90v when there is no power to the valve after calling for CH only) is
somehow tricking the boiler into staying running and I suspect the
boiler PCB is faulty.

How long have you been a regular here ?

How many times has someone been called a numpty for not saying what
boiler they have ?

-- geoff

Worcester 24Ri

I'll check tomorrow


--
geoff

Cheers

Adam

[YAPH]

On Sun, 04 Oct 2009 15:55:31 +0000, ARWadsworth wrote:

The only idea that I can come up with is that orange wire (which stays
at 90v when there is no power to the valve after calling for CH only)
is somehow tricking the boiler into staying running and I suspect the
boiler PCB is faulty.

Worcester 24Ri

Greenstar? Fit 0.47uF (275V AC X2 rated) capacitor across switched live.



--
John Stumbles -- http://yaph.co.uk

Women always generalise

[ARWadsworth]

"YAPH" wrote in message
...
On Sun, 04 Oct 2009 15:55:31 +0000, ARWadsworth wrote:

The only idea that I can come up with is that orange wire (which stays
at 90v when there is no power to the valve after calling for CH only)
is somehow tricking the boiler into staying running and I suspect the
boiler PCB is faulty.

Worcester 24Ri

Greenstar? Fit 0.47uF (275V AC X2 rated) capacitor across switched live.



--
John Stumbles -- http://yaph.co.uk

Women always generalise

Yes a Greenstar.

Worth a shot. Cheers for that.

Adam

[geoff]

In message ,
ARWadsworth writes

"YAPH" wrote in message
...
On Sun, 04 Oct 2009 15:55:31 +0000, ARWadsworth wrote:

The only idea that I can come up with is that orange wire (which stays
at 90v when there is no power to the valve after calling for CH only)
is somehow tricking the boiler into staying running and I suspect the
boiler PCB is faulty.

Worcester 24Ri

Greenstar? Fit 0.47uF (275V AC X2 rated) capacitor across switched live.



-- John Stumbles -- http://yaph.co.uk

Women always generalise

Yes a Greenstar.

Worth a shot. Cheers for that.


Common problem John ?


--
geoff

[ARWadsworth]

"ARWadsworth" wrote in message
. com...

"YAPH" wrote in message
...
On Sun, 04 Oct 2009 15:55:31 +0000, ARWadsworth wrote:

The only idea that I can come up with is that orange wire (which stays
at 90v when there is no power to the valve after calling for CH only)
is somehow tricking the boiler into staying running and I suspect the
boiler PCB is faulty.

Worcester 24Ri

Greenstar? Fit 0.47uF (275V AC X2 rated) capacitor across switched live.



--
John Stumbles -- http://yaph.co.uk

Women always generalise

Yes a Greenstar.

Worth a shot. Cheers for that.

Adam

Which end of the wiring? The boiler end or the airing cupboard end?

Adam

[ARWadsworth]

"YAPH" wrote in message
...
On Sun, 04 Oct 2009 15:55:31 +0000, ARWadsworth wrote:

The only idea that I can come up with is that orange wire (which stays
at 90v when there is no power to the valve after calling for CH only)
is somehow tricking the boiler into staying running and I suspect the
boiler PCB is faulty.

Worcester 24Ri

Greenstar? Fit 0.47uF (275V AC X2 rated) capacitor across switched live.



--
John Stumbles -- http://yaph.co.uk



I fitted one today. The boiler now works correctly.

Thanks

Adam

[YAPH]

On Sun, 04 Oct 2009 21:29:56 +0100, geoff wrote:

Worcester 24Ri
Greenstar? Fit 0.47uF (275V AC X2 rated) capacitor across switched live.

Common problem John ?

Pretty obscure actually - it was about 3rd time calling W-B tech
support before I found out about it. Basically it seems the small current
passed by Honeywell-type mid-position valves (presumably by that 680K or
whatever resistor?) can fool the electronics of these boilers (and maybe
some other models? & other makes even?) into thinking they have
call-for-heat at their switched-live input.

The boiler I came across would jitter on an off with a relay inside
chattering away until it gave up and went into lockout. I'd changed the
motorised valve and W-B had been out and (as I recall) changed it again
before I eventually found someone there who knew of this issue.

I'd actually tried hanging a resistor across switched-live thinking that
might cure it and was quite surprised at the capacitor suggestion, but it
did the trick and the system's been sweet as a nut since then. Odd thing
is the system had been up and running happily for a couple of years before
the problem showed up (and it was one of my installs so I'm pretty sure
nothing had changed in that time).

--
John Stumbles -- http://yaph.co.uk

I forgot to take my amnesia medecine again

[Roger Mills]

In an earlier contribution to this discussion,
YAPH wrote:


I'd actually tried hanging a resistor across switched-live thinking
that might cure it and was quite surprised at the capacitor
suggestion, but it did the trick and the system's been sweet as a nut
since then. Odd thing is the system had been up and running happily
for a couple of years before the problem showed up (and it was one of
my installs so I'm pretty sure nothing had changed in that time).

Can you please explain "across switched live". What does the other side
connect to, and how does it fix the problem?
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

[geoff]

In message , YAPH
writes
On Sun, 04 Oct 2009 21:29:56 +0100, geoff wrote:

Worcester 24Ri
Greenstar? Fit 0.47uF (275V AC X2 rated) capacitor across switched live.

Common problem John ?

Pretty obscure actually - it was about 3rd time calling W-B tech
support before I found out about it. Basically it seems the small current
passed by Honeywell-type mid-position valves (presumably by that 680K or
whatever resistor?) can fool the electronics of these boilers (and maybe
some other models? & other makes even?) into thinking they have
call-for-heat at their switched-live input.

The boiler I came across would jitter on an off with a relay inside
chattering away until it gave up and went into lockout. I'd changed the
motorised valve and W-B had been out and (as I recall) changed it again
before I eventually found someone there who knew of this issue.

I'd actually tried hanging a resistor across switched-live thinking that
might cure it and was quite surprised at the capacitor suggestion, but it
did the trick and the system's been sweet as a nut since then. Odd thing
is the system had been up and running happily for a couple of years before
the problem showed up (and it was one of my installs so I'm pretty sure
nothing had changed in that time).

Interesting reading

cheers


--
geoff

[John Stumbles]

On Thu, 08 Oct 2009 20:53:43 +0100, Roger Mills wrote:

Can you please explain "across switched live". What does the other side
connect to, and how does it fix the problem?

Neutral, and "dunno, it just does", respectively.

--
John Stumbles

There's nowt as queer as folk.
Especially other folk.

[ARWadsworth]

"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
YAPH wrote:


I'd actually tried hanging a resistor across switched-live thinking
that might cure it and was quite surprised at the capacitor
suggestion, but it did the trick and the system's been sweet as a nut
since then. Odd thing is the system had been up and running happily
for a couple of years before the problem showed up (and it was one of
my installs so I'm pretty sure nothing had changed in that time).

Can you please explain "across switched live". What does the other side
connect to, and how does it fix the problem?
--
Cheers,
Roger

Connected across to neutral. The switched live stayed at 90V when the last
call was from the CH.

The cap that Geoff so kindly posted to me dropped the voltage to 3V
(readings made with a DVM) after the CH was no longer called for.

As to how it fixes the problem then you need Geoff or John to answer. It is
long time ago that I did electronics.

Adam

[Roger Mills]

In an earlier contribution to this discussion,
ARWadsworth wrote:

"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
YAPH wrote:


I'd actually tried hanging a resistor across switched-live thinking
that might cure it and was quite surprised at the capacitor
suggestion, but it did the trick and the system's been sweet as a
nut since then. Odd thing is the system had been up and running
happily for a couple of years before the problem showed up (and it
was one of my installs so I'm pretty sure nothing had changed in
that time).

Can you please explain "across switched live". What does the other
side connect to, and how does it fix the problem?
--
Cheers,
Roger

Connected across to neutral. The switched live stayed at 90V when the
last call was from the CH.

The cap that Geoff so kindly posted to me dropped the voltage to 3V
(readings made with a DVM) after the CH was no longer called for.

As to how it fixes the problem then you need Geoff or John to answer.
It is long time ago that I did electronics.

Adam


Yes, I see - thanks. Whatever the exact electronics explanation, it
apparently reduces the switched live voltage to a very low value so that the
boiler is no longer fooled into firing when it shouldn't.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

[YAPH]

On Sat, 10 Oct 2009 11:05:51 +0000, ARWadsworth wrote:

Connected across to neutral. The switched live stayed at 90V when the
last call was from the CH.

The cap that Geoff so kindly posted to me dropped the voltage to 3V
(readings made with a DVM) after the CH was no longer called for.

So it worked?

As to how it fixes the problem then you need Geoff or John to answer. It
is long time ago that I did electronics.

I guess it simply attenuates the voltage seen at the SL terminal caused by
the high value (680K?) resistor in the motorised valve. It's too late in
the night (or early in the morning!) to ask my brain to do the sums
especially seeing as wot they has reactance at 50Hz in them and it's a
looong time since I did that stuff, but maybe some brainy sort will be
along soon to help us out here. :-)


--
John Stumbles -- http://yaph.co.uk

Teenagers: tired of being harassed by your stupid parents? Act now! -
Move out, get a job and pay your own bills, while you still know everything!

[ARWadsworth]

"YAPH" wrote in message
...
On Sat, 10 Oct 2009 11:05:51 +0000, ARWadsworth wrote:

Connected across to neutral. The switched live stayed at 90V when the
last call was from the CH.

The cap that Geoff so kindly posted to me dropped the voltage to 3V
(readings made with a DVM) after the CH was no longer called for.

So it worked?

My post on the 7th suggested that it did:-)

In case you missed that post, then Thank You.

Adam

[YAPH]

On Sun, 11 Oct 2009 09:38:49 +0000, ARWadsworth wrote:

So it worked?

My post on the 7th suggested that it did:-)

Yes, just checking that I'd read your post correctly. Brain in neutral and
all that :-)

In case you missed that post, then Thank You.

Glad it helped.
And to put one over on that know-it-all in Watford ducks ;-)



--
John Stumbles -- http://yaph.co.uk

Thesaurus: extinct reptile noted for its wide vocabulary.

[geoff]

In message , YAPH
writes
On Sun, 11 Oct 2009 09:38:49 +0000, ARWadsworth wrote:

So it worked?

My post on the 7th suggested that it did:-)

Yes, just checking that I'd read your post correctly. Brain in neutral and
all that :-)

In case you missed that post, then Thank You.

Glad it helped.
And to put one over on that know-it-all in Watford ducks ;-)



Makes note to add 10% smugness excess on next order

--
geoff

[YAPH]

On Sun, 11 Oct 2009 19:41:07 +0100, geoff wrote:

Makes note to add 10% smugness excess on next order

Curses! :-(



--
John Stumbles -- http://yaph.co.uk

A stitch in time saves nine. If it ain't broke, don't fix it.