On 01/04/2019 20:46, T i m wrote:
Hi all,

I got called over to the elderly lady across the road today as she
said her central heating was coming on along with her hot water.

I replaced the timer a good while ago (the plastic had gone brittle on
the old one and the internal battery had failed) so I was reasonably
sure it wasn't that.

Having a play with the 3 port valve I think there could be an issue
with that and a quick Google to faults on them suggested a couple of
things to check and I did:

I removed the head (two screw Honeywell type luckily so no water loss)
and I could move the actual valve with my fingers. However, it doesn't
seem to go though that many degrees end-to-end, but does seem to stop
fairly sharply at each end?

http://tinypic.com/r/244v3fp/9

If operated by hand with the system calling for heat (I turned the HW
stat up), when you turn it one way it seems to do so (diverting the
water) nearly silently, whereas when turned to the opposite extreme it
seems to do so with a 'bonk' (as if the water flow pressure is
flapping it shut, like a lock gate). ;-)

The spindle is connected to a small arm with a ball on the end of it.
The rotation just needs to shift the ball from the opening at one side
of the valve to the other - hence it does not take much rotation since
the arm only needs move through a small arc to work.


With the head off, if you gently reverse drive the motor with the side
arm, it allows you to push it to the end of the slot and then comes
back slowly on it's own under spring pressure (as it should)?

However, with it fitted to the actual valve, it only seems to come
back half way?

So, is the valve itself unable to rotate fully for some reason?
Something caught in there (some calcium?) and should I put an
adjustable on there and give it a firmer 'nudge' in the hope it might
shift it?

The motors (if working) have a fairly decent amount of torque.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 01/04/2019 20:46, T i m wrote:


With the head off, if you gently reverse drive the motor with the side
arm, it allows you to push it to the end of the slot and then comes
back slowly on it's own under spring pressure (as it should)?

However, with it fitted to the actual valve, it only seems to come
back half way?

So, is the valve itself unable to rotate fully for some reason?
Something caught in there (some calcium?) and should I put an
adjustable on there and give it a firmer 'nudge' in the hope it might
shift it?

I don't know about the Honeywell, but all of the 3-ports I have come
across can be freely rotated through 360. With all power off, the valve
and actuator should spring return all the way back, if they don't then
either the actuator or valve is sticking/jamming.

Spring return 3-ports actuators are notoriously unreliable, in my
experience. Two of the positions, require the motor to be powered, but
stalled to hold the position. Better and more elegant are the Momo
type, which motor to position, then switch off completely. Which is the
type I have now fitted, after decades of problems with the spring
return types.

On Tue, 2 Apr 2019 19:29:35 +0100, John Rumm
wrote:

snip

If operated by hand with the system calling for heat (I turned the HW
stat up), when you turn it one way it seems to do so (diverting the
water) nearly silently, whereas when turned to the opposite extreme it
seems to do so with a 'bonk' (as if the water flow pressure is
flapping it shut, like a lock gate). ;-)

The spindle is connected to a small arm with a ball on the end of it.
The rotation just needs to shift the ball from the opening at one side
of the valve to the other - hence it does not take much rotation since
the arm only needs move through a small arc to work.

That makes much more sense than me thinking it was like an isolator
ball valve as found on a washing machine feed tap. ;-)

Is it just me that would have this picture on the wall. ;-)

http://www.freeheatingadvice.com/wp-...valve_ball.jpg


The motors (if working) have a fairly decent amount of torque.

Understood.

So, from what she said, the CH is (also) coming on when it's set for
HW only.

This would suggest that the CH outlet isn't being (fully?) blocked
when in HW only.

If I understand it right, the default / un powered position of the
valve is normally providing HW and therefore means the CH outlet is
(supposed to be) being 'blocked' by the ball valve (using spring
tension alone)?

So, it's either not being driven correctly by the timer (still / also
feeding power as if it's calling for HW and CH) or just isn't seating
properly?

Cheers, T i m

On Tue, 02 Apr 2019 21:16:14 +0100, Harry Bloomfield
wrote:

On 01/04/2019 20:46, T i m wrote:


With the head off, if you gently reverse drive the motor with the side
arm, it allows you to push it to the end of the slot and then comes
back slowly on it's own under spring pressure (as it should)?

However, with it fitted to the actual valve, it only seems to come
back half way?

So, is the valve itself unable to rotate fully for some reason?
Something caught in there (some calcium?) and should I put an
adjustable on there and give it a firmer 'nudge' in the hope it might
shift it?

I don't know about the Honeywell, but all of the 3-ports I have come
across can be freely rotated through 360.

If you can rotate these 360 the valve would have broken off! ;-)

http://www.freeheatingadvice.com/wp-...valve_ball.jpg

With all power off, the valve
and actuator should spring return all the way back, if they don't then
either the actuator or valve is sticking/jamming.

Agreed. In the un powered position I believe it is HW only and so
should have the CH port blocked. If it isn't you would get 'some' CH
when in HW only and if it wasn't particularly cold out, could appear
to be full CH.

Spring return 3-ports actuators are notoriously unreliable, in my
experience. Two of the positions, require the motor to be powered, but
stalled to hold the position.

I think when in full travel the motor is just mechanically stalled but
when in the central position it is being stalled / held as you say.

Better and more elegant are the Momo
type, which motor to position, then switch off completely. Which is the
type I have now fitted, after decades of problems with the spring
return types.

And can they be wired straight into a Honeywell Y Plan (I think it is)
with no other modifications do you know?

Cheers, T i m

On 02/04/2019 21:50, T i m wrote:
On Tue, 2 Apr 2019 19:29:35 +0100, John Rumm
wrote:

snip

If operated by hand with the system calling for heat (I turned the HW
stat up), when you turn it one way it seems to do so (diverting the
water) nearly silently, whereas when turned to the opposite extreme it
seems to do so with a 'bonk' (as if the water flow pressure is
flapping it shut, like a lock gate). ;-)

The spindle is connected to a small arm with a ball on the end of it.
The rotation just needs to shift the ball from the opening at one side
of the valve to the other - hence it does not take much rotation since
the arm only needs move through a small arc to work.

That makes much more sense than me thinking it was like an isolator
ball valve as found on a washing machine feed tap. ;-)

Is it just me that would have this picture on the wall. ;-)

http://www.freeheatingadvice.com/wp-...valve_ball.jpg


The motors (if working) have a fairly decent amount of torque.

Understood.

So, from what she said, the CH is (also) coming on when it's set for
HW only.

This would suggest that the CH outlet isn't being (fully?) blocked
when in HW only.

Perhaps, or for some reason it is also "seeing" a CH demand, and hence
goes to mid position.

See the circus diagram:

http://wiki.diyfaq.org.uk/index.php/...on es:_Y-plan

If I understand it right, the default / un powered position of the
valve is normally providing HW and therefore means the CH outlet is
(supposed to be) being 'blocked' by the ball valve (using spring
tension alone)?

Yup:

http://wiki.diyfaq.org.uk/index.php/...position_valve


So, it's either not being driven correctly by the timer (still / also
feeding power as if it's calling for HW and CH) or just isn't seating
properly?

Yup, those seem the obvious options.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Tuesday, 2 April 2019 22:24:09 UTC+1, John Rumm wrote:
On 02/04/2019 21:50, T i m wrote:
On Tue, 2 Apr 2019 19:29:35 +0100, John Rumm
wrote:

snip

If operated by hand with the system calling for heat (I turned the HW
stat up), when you turn it one way it seems to do so (diverting the
water) nearly silently, whereas when turned to the opposite extreme it
seems to do so with a 'bonk' (as if the water flow pressure is
flapping it shut, like a lock gate). ;-)

The spindle is connected to a small arm with a ball on the end of it.
The rotation just needs to shift the ball from the opening at one side
of the valve to the other - hence it does not take much rotation since
the arm only needs move through a small arc to work.

That makes much more sense than me thinking it was like an isolator
ball valve as found on a washing machine feed tap. ;-)

Is it just me that would have this picture on the wall. ;-)

http://www.freeheatingadvice.com/wp-...valve_ball.jpg


The motors (if working) have a fairly decent amount of torque.

Understood.

So, from what she said, the CH is (also) coming on when it's set for
HW only.

This would suggest that the CH outlet isn't being (fully?) blocked
when in HW only.

Perhaps, or for some reason it is also "seeing" a CH demand, and hence
goes to mid position.

See the circus diagram:

http://wiki.diyfaq.org.uk/index.php/...on es:_Y-plan

If I understand it right, the default / un powered position of the
valve is normally providing HW and therefore means the CH outlet is
(supposed to be) being 'blocked' by the ball valve (using spring
tension alone)?

Yup:

http://wiki.diyfaq.org.uk/index.php/...position_valve


So, it's either not being driven correctly by the timer (still / also
feeding power as if it's calling for HW and CH) or just isn't seating
properly?

Yup, those seem the obvious options.

I'd expect the most likely problem to be a stiff shaft. We know the motor runs, as it's not stuck on HW only. Next most likely failure AIUI is the shaft sticking in the valvey bit (not the motorised head). So you've got a motorhead with a stuck shaft.


NT

On Tue, 2 Apr 2019 22:24:07 +0100, John Rumm
wrote:

snip

This would suggest that the CH outlet isn't being (fully?) blocked
when in HW only.

Perhaps, or for some reason it is also "seeing" a CH demand, and hence
goes to mid position.

I was thinking of slackening of putting a couple of washers under the
two screws that hold the head to the body and making up a wire pointer
that can extend past the outside of the body. That way you can see
exactly what state the valve is in (for testing)?

See the circus diagram:

http://wiki.diyfaq.org.uk/index.php/...on es:_Y-plan

Yeah, I got all that from GymRatZ link and associated video etc.

If I understand it right, the default / un powered position of the
valve is normally providing HW and therefore means the CH outlet is
(supposed to be) being 'blocked' by the ball valve (using spring
tension alone)?

Yup:

http://wiki.diyfaq.org.uk/index.php/...position_valve


So, it's either not being driven correctly by the timer (still / also
feeding power as if it's calling for HW and CH) or just isn't seating
properly?

Yup, those seem the obvious options.

I was just wondering if there was a 'common' failure mode that gave
those symptoms?

Cheers, T i m

On Tue, 2 Apr 2019 14:32:17 -0700 (PDT), wrote:

snip

I'd expect the most likely problem to be a stiff shaft.

Except I can easily turn it between end-stops with my fingers?

We know the motor runs, as it's not stuck on HW only.

TBF we don't, we only know that the rads also get hot when the HW is
called?

Next most likely failure AIUI is the shaft sticking in the valvey bit (not the motorised head). So you've got a motorhead with a stuck shaft.#

Covered above.

The manual arm thing isn't directly connected to the valve arm /
spindle so you get a distorted idea of what is *actually* happening in
there.

Reading around, with the power off, it suggested that if you pushed
the manual lever to the far end against the spring, it should slowly
come back under spring tension. With the head disconnected it does but
with it connected it doesn't (but the valve can be easily actioned
with your fingers). It also seems it may also depend on 'other' things
but I haven't worked out what they are yet?

Cheers, T i m

On Tuesday, 2 April 2019 23:52:32 UTC+1, T i m wrote:
On Tue, 2 Apr 2019 14:32:17 -0700 (PDT), tabbypurr wrote:

snip

I'd expect the most likely problem to be a stiff shaft.

Except I can easily turn it between end-stops with my fingers?

We know the motor runs, as it's not stuck on HW only.

TBF we don't, we only know that the rads also get hot when the HW is
called?

Next most likely failure AIUI is the shaft sticking in the valvey bit (not the motorised head). So you've got a motorhead with a stuck shaft.#

Covered above.

The manual arm thing isn't directly connected to the valve arm /
spindle so you get a distorted idea of what is *actually* happening in
there.

Reading around, with the power off, it suggested that if you pushed
the manual lever to the far end against the spring, it should slowly
come back under spring tension. With the head disconnected it does but
with it connected it doesn't (but the valve can be easily actioned
with your fingers). It also seems it may also depend on 'other' things
but I haven't worked out what they are yet?

Cheers, T i m

The valve moves under its own spring power to the HW only position. I'm thinking if it's not in that position, the shaft has to be too stiff for the spring to move it back. Your account seems at odds with that I know. Why don't you move the thing manually to the HW only position, switch CH off then power it up, check its position. Then turn CH on as well as HW, turning the room stat up, and see if it changes its position.


NT

On Tue, 2 Apr 2019 17:36:23 -0700 (PDT), wrote:
snip||

The valve moves under its own spring power to the HW only position.

Check (it should / might be).

I'm thinking if it's not in that position, the shaft has to be too stiff for the spring to move it back.

Well I can confirm the shaft isn't in any way seized as I can *easily*
flop the valve backwards and forwards with my fingers.

Your account seems at odds with that I know.

Well, you can't easily see where the shaft is pointing when it's all
in place and the manual override arm isn't a direct translation of
that either, so, the fact that there seems to be a difference between
how the arm reacts with the head disconnected from the valve may not
indicate a / the fault.

Why don't you move the thing manually to the HW only position, switch CH off then power it up, check its position.

As I mentioned elsewhere, I think I'll try to space the head off the
valve slightly with some washers and leave a wire pointer in there to
give me a visual indication of the actual valves position at any time.

Then turn CH on as well as HW, turning the room stat up, and see if it changes its position.

No room stat mate. There is only a cylinder stat and thermostatic rad
valves so relies on the return temp on the boiler to manage the CH.

What I can do is with the system cold, take the head off, put the
valve in HW only and just run the system up. If the CH gets hot as
well then it *has* to be the physical valve. ;-)

Cheers, T i m

T i m wrote:

On Tue, 2 Apr 2019 17:36:23 -0700 (PDT), wrote:
snip||

The valve moves under its own spring power to the HW only position.

Check (it should / might be).

I'm thinking if it's not in that position, the shaft has to be too stiff
for the spring to move it back.

Well I can confirm the shaft isn't in any way seized as I can *easily*
flop the valve backwards and forwards with my fingers.

Your account seems at odds with that I know.

Well, you can't easily see where the shaft is pointing when it's all
in place and the manual override arm isn't a direct translation of
that either, so, the fact that there seems to be a difference between
how the arm reacts with the head disconnected from the valve may not
indicate a / the fault.

Why don't you move the thing manually to the HW only position, switch CH
off then power it up, check its position.

As I mentioned elsewhere, I think I'll try to space the head off the
valve slightly with some washers and leave a wire pointer in there to
give me a visual indication of the actual valves position at any time.

Then turn CH on as well as HW, turning the room stat up, and see if it
changes its position.

No room stat mate. There is only a cylinder stat and thermostatic rad
valves so relies on the return temp on the boiler to manage the CH.

What I can do is with the system cold, take the head off, put the
valve in HW only and just run the system up. If the CH gets hot as
well then it *has* to be the physical valve. ;-)

Cheers, T i m

Many years ago I had a problem with one of these valves where the rubber
ball that actually occludes the ports had swollen up and didn't fit any
more. I don't know if this stll happens - or whether it was an unusual
fault at the time, but it made the valve very leaky.


--

Roger Hayter

On Wed, 3 Apr 2019 10:00:31 +0100, (Roger Hayter)
wrote:

snip

What I can do is with the system cold, take the head off, put the
valve in HW only and just run the system up. If the CH gets hot as
well then it *has* to be the physical valve. ;-)


Many years ago I had a problem with one of these valves where the rubber
ball that actually occludes the ports had swollen up and didn't fit any
more.

Ahhh ..

I don't know if this stll happens - or whether it was an unusual
fault at the time, but it made the valve very leaky.

This is the sort of thing I'm wondering Roger, as I learn more about
how these things work.

I understand the ball is designed to be allowed to rotate so that (in
theory) a fresh 'face' can be presented to the valve(s) ... assuming
it can still and wants to rotate etc?

If the ball is distorted and can rotate then in theory the 'fault'
(leakpast) will still happen but would be random. However, I think
there may be a stronger closing force applied by the motor (so that
would be the CH only position) than the return spring might be able to
apply in the HW (only) position, meaning the fault more of that cause
is more likely to see unwanted HW than CH?

When I was playing with the valve spindle with the system (boiler /
pump) on, turning the shaft to the right (that I think might be HW)
definitely caused the ball to seat with a 'thump' (like water hammer)
whereas to the left it was hardly noticeable [1]. Maybe the valve
being forced shut (in that direction) could have distorted it?

Time will tell. ;-)

Cheers, T i m

[1] Before learning the 'valve' was actually a ball on a stick (like a
ball cock) rather than a ball valve (like a WM isolator), it 'felt'
more like a simple metal flap like the old hot / cold diverter flap /
control in car heater / blowers but I couldn't see how that would seal
very well. A rubber ball makes more sense.

On 02/04/2019 21:50, T i m wrote:


So, it's either not being driven correctly by the timer (still / also
feeding power as if it's calling for HW and CH) or just isn't seating
properly?

Cheers, T i m


And I had similar symptoms with this type of 3 way valve (CH coming on
in summer when HW only called for) - Taking the valve apart after it had
been changed (as you do - just to find out how it worked) showed that 25
years of use had worn away a significant groove on the rubber ball and
permitted leakage. (I also suspect that the rubber was somewhat less
flexible than when new which wasn't helping)


--
Chris B (News)

On Thu, 4 Apr 2019 11:28:39 +0100, Chris B wrote:

On 02/04/2019 21:50, T i m wrote:


So, it's either not being driven correctly by the timer (still / also
feeding power as if it's calling for HW and CH) or just isn't seating
properly?


And I had similar symptoms with this type of 3 way valve (CH coming on
in summer when HW only called for)

Ok ...

- Taking the valve apart after it had
been changed (as you do - just to find out how it worked)

Of course! [1]

showed that 25
years of use had worn away a significant groove on the rubber ball and
permitted leakage.

Hmm, I thought the ball was free to rotate and so *should* spread the
wear around (like a very early version of SSD wear leveling g)

(I also suspect that the rubber was somewhat less
flexible than when new which wasn't helping)

And when you consider that it is in cold water one minute then very
hot water the next ... and for many years ... hardly surprising? ;-)

I have been up to my neck since I posted and it's been a bit colder so
she may well have the CH on in any case. I hope to try the manual
override (turn the spindle with my fingers) with it in the HW position
from cold and see what I can feel. Luckily it's all *very* easy to
get at.

Cheers, T i m