Following an unplanned cold shower this morning I would be appreciative
of an explanation of the workings of the single port version.

Manually forcing the valve open allows water into the cistern coil but
does not start the pump or boiler. Pump and boiler run OK from the
central heating command.

ISTR having to replace the valve coil before but cannot remember the
symptoms.

AFAIAA this is an S plan set up.

regards
--
Tim Lamb

Tim Lamb
wibbled on Thursday 05 November 2009 08:34

Following an unplanned cold shower this morning I would be appreciative
of an explanation of the workings of the single port version.

Manually forcing the valve open allows water into the cistern coil but
does not start the pump or boiler. Pump and boiler run OK from the
central heating command.

So there's no microswitch on the valve? Often there is, so that the valve
must be proven operated before the system will pump/fire. This does have
the advantage that if the coil's gone, then manual operation is possible.

ISTR having to replace the valve coil before but cannot remember the
symptoms.

Sounds like the motor.

AFAIAA this is an S plan set up.

regards

--
Tim Watts

This space intentionally left blank...

Tim Lamb wrote:
Following an unplanned cold shower this morning I would be appreciative
of an explanation of the workings of the single port version.

Manually forcing the valve open allows water into the cistern coil but
does not start the pump or boiler. Pump and boiler run OK from the
central heating command.

If it's the 4043H valve, then it's either

1- the microswitch inside the head body has gone open circuit, or the
associated wiring to that has failed. The motor drives the valve open
and should strike that.

2 - the motor has died.

However, if you are manually forcing the valve with the lever, and it's
not going, I'd go with the first one. You can check by taking off the
top of the body of the head, and with the valve forced open try
operating the microswitch (with a bit of wood - mains voltages beware).

ISTR having to replace the valve coil before but cannot remember the
symptoms.

That head is available seperately for about £50-£60. I keep the old ones
for Frankenstein replacement work of bits. I've also stuck coloured neon
lights across both HW & CH motors circuit for both valves, so I can
readily see what's going wrong.

--
Adrian C

Adrian C wrote:
Tim Lamb wrote:
Following an unplanned cold shower this morning I would be
appreciative of an explanation of the workings of the single port
version.

Manually forcing the valve open allows water into the cistern coil but
does not start the pump or boiler. Pump and boiler run OK from the
central heating command.

Sorry, I read it wrong.

The valve is not being driven
If forced, the boiler does not switch on

Not the valve head. Got to be somewhere else? Confuzzled.

--
Adrian C

On Thu, 05 Nov 2009 08:34:49 +0000, Tim Lamb wrote:

Following an unplanned cold shower this morning I would be appreciative
of an explanation of the workings of the single port version.

Manually forcing the valve open allows water into the cistern coil but
does not start the pump or boiler. Pump and boiler run OK from the
central heating command.

If the valve is getting mains voltage across its brown and blue wires
from the programmer and cylinder thermostat, but not opening, then it's a
valve problem; otherwise the problem is with the programmer or cylinder
stat.

If it's a valve problem then, when you manually open the valve, does it
feel abnormally still (compared to the central heating valve)? If it's
stiff then the hydronic part of the valve is probably knackered and you'll
need a new valve. Otherwise it may be the head, possibly just the motor.


If it's a Honeywell with a metal cover then if you take the cover off the
head you can see how the gear train operates when you move the override
lever manually: it opens the valve hydronically, but there's a sort of
folded tag on the brass gear which has to push the button on a microswitch
to make it work electrically (i.e. to tell the boiler to fire up). You can
prod the microswitch button using e.g. an insulated screwdriver to test
this.

Motors are about £10 and are easy to fit - remove one screw, twist the
motor and pull it out, swap wires over and refit new motor.

ISTR having to replace the valve coil before but cannot remember the
symptoms.

If by 'coil' you mean motor sounds as if you've done this before.

Mains power off while doing it, of course!


--
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!

In message , Tim Lamb
writes
Following an unplanned cold shower this morning I would be appreciative
of an explanation of the workings of the single port version.

Manually forcing the valve open allows water into the cistern coil but
does not start the pump or boiler. Pump and boiler run OK from the
central heating command.

ISTR having to replace the valve coil before but cannot remember the
symptoms.

AFAIAA this is an S plan set up.

OK Chaps.

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

If it does then the problem is the switch or the wiring. If not then the
problem could include the tank stat.

This is the sheet steel covered valve and yes the *motor* has been
changed before.

Prodding anything with a screwdriver involves disassembling the entire
airing cupboard whereas the tank stat is easily accessible:-(

Thanks

--
Tim Lamb

In article , Tim Lamb
writes
In message , Tim Lamb
writes
Following an unplanned cold shower this morning I would be appreciative
of an explanation of the workings of the single port version.

Manually forcing the valve open allows water into the cistern coil but
does not start the pump or boiler. Pump and boiler run OK from the
central heating command.

ISTR having to replace the valve coil before but cannot remember the
symptoms.

AFAIAA this is an S plan set up.

OK Chaps.

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No, on a Honeywell 2 port valve, manual operation of the valve does not
operate the microswitch.

When the valve is off, the manual lever should spring to the off
position and operating the valve manually should have some spring
opposition.

If the valve motor is operating the valve then the manual lever will be
moveable without opposition.

If no opposition, it points to the microswitch which can be replaced on
its own. From memory it's a V3 type button microswitch but with the
connection tabs cut very short and soldered to. Usual suspects or
http://rswww.com are good for this sort of thing.
--
fred
BBC3, ITV2/3/4, channels going to the DOGs

In message , fred writes

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No, on a Honeywell 2 port valve, manual operation of the valve does
not operate the microswitch.

Ah!

When the valve is off, the manual lever should spring to the off
position and operating the valve manually should have some spring
opposition.

Yes.

If the valve motor is operating the valve then the manual lever will be
moveable without opposition.

Definitely opposition.

If no opposition, it points to the microswitch which can be replaced on
its own. From memory it's a V3 type button microswitch but with the
connection tabs cut very short and soldered to. Usual suspects or
http://rswww.com are good for this sort of thing.

Sounds like the motor.

Job for tomorrow.

The boss is away so I am self catering or rather microwaving prepared
meals.

Thanks again.

--
Tim Lamb

In message , John
Rumm writes
Tim Lamb wrote:

Prodding anything with a screwdriver involves disassembling the
entire airing cupboard whereas the tank stat is easily accessible:-(

Can you get to the wiring centre?

Yes.

From what Fred has said, the motor looks to be suspect.

I'll unload and remove the shelves this evening.

I am hurrying to finish erecting a barn roof before the weather changes
again.

regards


--
Tim Lamb

In article , Tim Lamb
writes
In message , fred writes

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No, on a Honeywell 2 port valve, manual operation of the valve does
not operate the microswitch.

Ah!

When the valve is off, the manual lever should spring to the off
position and operating the valve manually should have some spring
opposition.

Yes.

If the valve motor is operating the valve then the manual lever will be
moveable without opposition.

Definitely opposition.

If no opposition, it points to the microswitch which can be replaced on
its own. From memory it's a V3 type button microswitch but with the
connection tabs cut very short and soldered to. Usual suspects or
http://rswww.com are good for this sort of thing.

Sounds like the motor.

Have you eliminated the cylinder stat? In case it helps, the coil
resistance of a good motor will be about 2.5kohms, you should be able to
check that from the stat end if is more accessible, one term will be
live (but turned off), the other should be connected to the valve motor
with the other end of the motor going to neutral.
--
fred
BBC3, ITV2/3/4, channels going to the DOGs

In message , fred writes
In article , Tim Lamb
writes

Sounds like the motor.

Have you eliminated the cylinder stat? In case it helps, the coil
resistance of a good motor will be about 2.5kohms, you should be able
to check that from the stat end if is more accessible, one term will be
live (but turned off), the other should be connected to the valve motor
with the other end of the motor going to neutral.

OK. I'll look tonight.

regards

--
Tim Lamb

On Thu, 5 Nov 2009 11:19:50 +0000, Tim Lamb wrote:

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No.

Prodding anything with a screwdriver involves disassembling the entire
airing cupboard whereas the tank stat is easily accessible:-(

Why do plumbers install things so you can't get at them to service
them?

One other thing to think about is that the motor might be working
fine but not quite enough grunt to fully open the valve and/or
operate the microswitch. One of mine plays up like that occasionally.
When closed and then powered up you may be able to hear a quiet
whirring as it motors open. If it should be on/open and has been on
for a minute or so on turning it off you should hear it whirring
closed.

--
Cheers
Dave.

Tim Lamb wrote:


I suppose my question should have been *does operating the valve
manually also operate the microswitch*?


No, it does not.
It ONLY opens the water part of the valve.

When you manually open these valves, when it's not opened electrically,
they should feel fairly 'stiff', as you manually drive the gear
mechanism. It should take a few seconds of sustained finger pressure
to move the lever through it's operating range.

If the valve is already open electrically, the manual lever will flap
about loosely.

Only electrical opening will activate the microswitch ( or a screwdriver! )

The looseness of the lever is an important diagnostic tool!

If it's stiff, but manually moveable, the valve is not seized, but it
not being operated electrically. Either there's no power to it, or the
motor is kaput. Use a meter to discover which.

If it's stiff, and not maually moveable, the wet part of the valve is
probably seized.

If it's flapping loosely, the valve is activated, and the microswitch
*should* have operated. Use a meter to fault-find further.

--
Ron

In message o.uk, Dave
Liquorice writes
On Thu, 5 Nov 2009 11:19:50 +0000, Tim Lamb wrote:

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No.

Prodding anything with a screwdriver involves disassembling the entire
airing cupboard whereas the tank stat is easily accessible:-(

Why do plumbers install things so you can't get at them to service
them?

I have to confess. The plumber installed his mares nest of pipes in an
open space. The builders chippies then built cupboards. The householder
then put in lift out shelving as directed by higher authority. The
result is that the hot water valve is trapped by the shelving and the
supposedly automatic air bleed is buried in a flock of towels or
gentlemen's underwear.

One other thing to think about is that the motor might be working
fine but not quite enough grunt to fully open the valve and/or
operate the microswitch. One of mine plays up like that occasionally.
When closed and then powered up you may be able to hear a quiet
whirring as it motors open. If it should be on/open and has been on
for a minute or so on turning it off you should hear it whirring
closed.

No whirring.

Big mistake tonight. I have been microwaving meals directly from the
freezer. Today's moussaka turns out to be 45 mins. oven only.

regards


--
Tim Lamb

In message , Ron Lowe
writes
Tim Lamb wrote:

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?


No, it does not.
It ONLY opens the water part of the valve.

When you manually open these valves, when it's not opened electrically,
they should feel fairly 'stiff', as you manually drive the gear
mechanism. It should take a few seconds of sustained finger pressure
to move the lever through it's operating range.

If the valve is already open electrically, the manual lever will flap
about loosely.

Only electrical opening will activate the microswitch ( or a screwdriver! )

The looseness of the lever is an important diagnostic tool!

If it's stiff, but manually moveable, the valve is not seized, but it
not being operated electrically. Either there's no power to it, or
the motor is kaput. Use a meter to discover which.

If it's stiff, and not maually moveable, the wet part of the valve is
probably seized.

If it's flapping loosely, the valve is activated, and the microswitch
*should* have operated. Use a meter to fault-find further.

While waiting for the moussaka to cool, zillions of towels not seen for
the last decade, shelving and valve cover removed. Now who in their
right mind installs a valve such that the cover release screw is 30mm
away from the cistern lagging?

Operating the micro switch starts the pump and fires up the boiler.
Access to the motor connections is not easy but I can get to the control
box and will check that the motor is energised. Trip to the nearest
plumbing outlet tomorrow.

Thanks to all


--
Tim Lamb

On Thu, 05 Nov 2009 11:19:50 +0000, Tim Lamb wrote:

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No, I don't think it does (at least, it didn't on the one I repaired last
week).



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

Bad artists borrow
Great artists steal
Igor Stravinsky

In message , YAPH
writes
On Thu, 05 Nov 2009 11:19:50 +0000, Tim Lamb wrote:

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No, I don't think it does (at least, it didn't on the one I repaired last
week).

You are correct.

As others have said, the tab does not reach the microswitch button when
the valve is operated manually.

I found 234V across the motor winding last night so I am confident that
a replacement will sort out my problem.

regards




--
Tim Lamb

In message , Tim Lamb
writes
In message , YAPH
writes
On Thu, 05 Nov 2009 11:19:50 +0000, Tim Lamb wrote:

I suppose my question should have been *does operating the valve
manually also operate the microswitch*?

No, I don't think it does (at least, it didn't on the one I repaired last
week).

You are correct.

As others have said, the tab does not reach the microswitch button when
the valve is operated manually.

I found 234V across the motor winding last night so I am confident
that a replacement will sort out my problem.

Job done!

Once again uk.d-i-y triumphs over adversity and the vicissitudes of
plumbing systems.

Synchron motor, 15ukp but probably not the cheapest source.

regards and thanks to all

--
Tim Lamb

YAPH wrote:

Motors are about £10 and are easy to fit - remove one screw, twist the
motor and pull it out, swap wires over and refit new motor.

Obviously I'm paying too much for my complete head replacements. Any
online sources for these?

--
Adrian C