Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil

thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil
When the downstairs only problem arises, is the demand for heat signal
arriving at the boiler (maybe dodgy demand switch inside downstairs zone
valve) if so is the pump running or has the boiler shut down due to
internal overheat?
I'm thinking that maybe downstairs flow is constricted somewhere or has
air in so that heat is not flowing to the rads, boiler gets over hot and
shuts down. In this circumstance the boiler should slowly cool, fire
again and quickly shut down as it heat itself up to over heat once more.

Also what happens if you manually open the lower zone valve.

We need more info as to the state of all the system components when the
"fault" is active and if they change over time eg any type of slow cycling

thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil


If I understand these things correctly, they way they should work is that
the thermostat controls the motorised valve and then the micro switch in
the motorised valve powers the boiler/pump.

If the motorised valve is opening, which it seems to be, then I would
suspect a faulty micro switch that is perhaps failing is some way as it
heats up causing the boiler to shut down again.

Should be easy enough to test.

Tim

--
Please don't feed the trolls

thescullster wrote:

Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil

Sounds as though the CH circulating pump is not coming on when only the
downstairs is calling for heat. This might be due to failure of a
switch internal to the downstairs valve, if it ihas one. Otherwise, an
obscure type of fault most likely a failed connection somewhere.


--

Roger Hayter

On 05/10/2016 10:19, Tim+ wrote:
thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil


If I understand these things correctly, they way they should work is that
the thermostat controls the motorised valve and then the micro switch in
the motorised valve powers the boiler/pump.

If the motorised valve is opening, which it seems to be, then I would
suspect a faulty micro switch that is perhaps failing is some way as it
heats up causing the boiler to shut down again.

Should be easy enough to test.

Tim


Hi Tim

This was my initial thought also. That the valve is opening, but not
far enough to operate the micro-switch jobby.
If the valve is partially open, this would explain how come the
downstairs rads get hot when both upstairs and down stats are calling
for heat.

Is it possible to remove the top "cover" on the valve motor to see
what's happening with the valve in situ?

If not, how is this failure "easy enough to test"?
I didn't install the valves or wire them, so am not clear what would
present if I open the wiring centre/junction boxes linking the valves
and programmers.

Thanks

Phil

On 05/10/2016 10:01, Bob Minchin wrote:
thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil
When the downstairs only problem arises, is the demand for heat signal
arriving at the boiler (maybe dodgy demand switch inside downstairs zone
valve) if so is the pump running or has the boiler shut down due to
internal overheat?
I'm thinking that maybe downstairs flow is constricted somewhere or has
air in so that heat is not flowing to the rads, boiler gets over hot and
shuts down. In this circumstance the boiler should slowly cool, fire
again and quickly shut down as it heat itself up to over heat once more.

Also what happens if you manually open the lower zone valve.

We need more info as to the state of all the system components when the
"fault" is active and if they change over time eg any type of slow cycling

Hi Bob

I don't believe the demand for heat signal can be reaching the boiler.
It has behaved fine serving the hot water circuit over summer and reacts
correctly when upstairs stat calls for heat.

As mentioned, the downstairs heats up OK if the upstairs stat also calls
for heat, so don't suspect a blockage.
I also think a boiler overheat is unlikely as this tends to show as a
flashing indicator light on the boiler which didn't happen.

I'll look at manually operating the zone valve a few times and see if
it's just a lack of use/partial seizure type situation.

I have not seen any cycling occurring, but it's a bit of a complex
system so takes a while to test each circuit.

Many thanks

Phil

On 05/10/2016 11:48, thescullster wrote:
On 05/10/2016 10:19, Tim+ wrote:
thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil


If I understand these things correctly, they way they should work is that
the thermostat controls the motorised valve and then the micro switch in
the motorised valve powers the boiler/pump.

If the motorised valve is opening, which it seems to be, then I would
suspect a faulty micro switch that is perhaps failing is some way as it
heats up causing the boiler to shut down again.

Should be easy enough to test.

Tim


Hi Tim

This was my initial thought also. That the valve is opening, but not
far enough to operate the micro-switch jobby.
If the valve is partially open, this would explain how come the
downstairs rads get hot when both upstairs and down stats are calling
for heat.

Is it possible to remove the top "cover" on the valve motor to see
what's happening with the valve in situ?

If not, how is this failure "easy enough to test"?
I didn't install the valves or wire them, so am not clear what would
present if I open the wiring centre/junction boxes linking the valves
and programmers.

Thanks

Phil


I would swap the two valve heads, without changing any of the wiring.
Then crank up the "wrong" thermostat and see what happens. It'll tell
you whether it's the electrical or mechanical part of the system that's
at fault.

Also, wasn't there a thread about gate valve problems. You haven't
fiddled with any of them?

On 05/10/2016 12:02, GB wrote:
On 05/10/2016 11:48, thescullster wrote:
On 05/10/2016 10:19, Tim+ wrote:
thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for
heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download
here,
the most relevant being the first. The valves are labelled. But as
the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil


If I understand these things correctly, they way they should work is
that
the thermostat controls the motorised valve and then the micro switch in
the motorised valve powers the boiler/pump.

If the motorised valve is opening, which it seems to be, then I would
suspect a faulty micro switch that is perhaps failing is some way as it
heats up causing the boiler to shut down again.

Should be easy enough to test.

Tim


Hi Tim

This was my initial thought also. That the valve is opening, but not
far enough to operate the micro-switch jobby.
If the valve is partially open, this would explain how come the
downstairs rads get hot when both upstairs and down stats are calling
for heat.

Is it possible to remove the top "cover" on the valve motor to see
what's happening with the valve in situ?

If not, how is this failure "easy enough to test"?
I didn't install the valves or wire them, so am not clear what would
present if I open the wiring centre/junction boxes linking the valves
and programmers.

Thanks

Phil


I would swap the two valve heads, without changing any of the wiring.
Then crank up the "wrong" thermostat and see what happens. It'll tell
you whether it's the electrical or mechanical part of the system that's
at fault.

Also, wasn't there a thread about gate valve problems. You haven't
fiddled with any of them?





Thanks GB

Good call swapping the heads over, that would give me a start.

No I haven't been twiddling gate valves yet. Although I got the
installer to fit them, I suspect with the pipe layout I might end up
having to release both valves to get enough pipe movement to free one of
them IYSWIM.

Phil

On 05/10/2016 12:13, thescullster wrote:

No I haven't been twiddling gate valves yet. Although I got the
installer to fit them, I suspect with the pipe layout I might end up
having to release both valves to get enough pipe movement to free one of
them IYSWIM.

Phil

I was able to get a new insert for my 3 way valve. That replaced all the
valve gubbins inside the body. That's easier than changing the whole
valve.

On Wed, 05 Oct 2016 11:54:31 +0100
thescullster wrote:

I'll look at manually operating the zone valve a few times and see if
it's just a lack of use/partial seizure type situation.

As mentioned in a different thread, remember that manually operating
the valve does not always trip the microswitch. But the switch can be
operated directly, with a pencil or ballpoint pen, to see if this does
then operate the pump and boiler.
You can try this with the valve powered open, too, to see if anything
happens. It may be that the switch is not being activated.

--
Davey.

On 05/10/2016 12:20, GB wrote:
On 05/10/2016 12:13, thescullster wrote:

No I haven't been twiddling gate valves yet. Although I got the
installer to fit them, I suspect with the pipe layout I might end up
having to release both valves to get enough pipe movement to free one of
them IYSWIM.

Phil

I was able to get a new insert for my 3 way valve. That replaced all the
valve gubbins inside the body. That's easier than changing the whole valve.

Thanks GB

I'll bear that in mind.

Phil

On 05/10/2016 12:23, Davey wrote:
On Wed, 05 Oct 2016 11:54:31 +0100
thescullster wrote:

I'll look at manually operating the zone valve a few times and see if
it's just a lack of use/partial seizure type situation.

As mentioned in a different thread, remember that manually operating
the valve does not always trip the microswitch. But the switch can be
operated directly, with a pencil or ballpoint pen, to see if this does
then operate the pump and boiler.
You can try this with the valve powered open, too, to see if anything
happens. It may be that the switch is not being activated.


Hi Davey

Is it necessary/possible to take the cover off the head to do this?


Thanks

Phil

On Wed, 05 Oct 2016 13:43:32 +0100
thescullster wrote:

On 05/10/2016 12:23, Davey wrote:
On Wed, 05 Oct 2016 11:54:31 +0100
thescullster wrote:

I'll look at manually operating the zone valve a few times and see
if it's just a lack of use/partial seizure type situation.

As mentioned in a different thread, remember that manually operating
the valve does not always trip the microswitch. But the switch can
be operated directly, with a pencil or ballpoint pen, to see if
this does then operate the pump and boiler.
You can try this with the valve powered open, too, to see if
anything happens. It may be that the switch is not being activated.


Hi Davey

Is it necessary/possible to take the cover off the head to do this?


Thanks

Phil

Yes. It should be one screw, that only needs loosening, and is probably
on the bottom of the cover. If you can find the most awkward place for
a screw to be located, that's where it will be! Once it's loose, the
cover should slide directly away from the valve, revealing the motor,
wires, and switch.

--
Davey.

On 05/10/2016 14:15, Davey wrote:
On Wed, 05 Oct 2016 13:43:32 +0100
thescullster wrote:

On 05/10/2016 12:23, Davey wrote:
On Wed, 05 Oct 2016 11:54:31 +0100
thescullster wrote:

I'll look at manually operating the zone valve a few times and see
if it's just a lack of use/partial seizure type situation.

As mentioned in a different thread, remember that manually operating
the valve does not always trip the microswitch. But the switch can
be operated directly, with a pencil or ballpoint pen, to see if
this does then operate the pump and boiler.
You can try this with the valve powered open, too, to see if
anything happens. It may be that the switch is not being activated.


Hi Davey

Is it necessary/possible to take the cover off the head to do this?


Thanks

Phil

Yes. It should be one screw, that only needs loosening, and is probably
on the bottom of the cover. If you can find the most awkward place for
a screw to be located, that's where it will be! Once it's loose, the
cover should slide directly away from the valve, revealing the motor,
wires, and switch.


Thanks Davey

I'll do my limbering up exercises ready for attempting to contort myself
(probably upside down) into the smallest space in the airing cupboard,
then moan cos the exertion has caused my glasses to steam up so I can't
see the hot water cylinder let alone a screw in the most inaccessible
recess possible.

Phil

On 05/10/2016 15:50, thescullster wrote:
On 05/10/2016 14:15, Davey wrote:
On Wed, 05 Oct 2016 13:43:32 +0100
thescullster wrote:

On 05/10/2016 12:23, Davey wrote:
On Wed, 05 Oct 2016 11:54:31 +0100
thescullster wrote:

I'll look at manually operating the zone valve a few times and see
if it's just a lack of use/partial seizure type situation.

As mentioned in a different thread, remember that manually operating
the valve does not always trip the microswitch. But the switch can
be operated directly, with a pencil or ballpoint pen, to see if
this does then operate the pump and boiler.
You can try this with the valve powered open, too, to see if
anything happens. It may be that the switch is not being activated.


Hi Davey

Is it necessary/possible to take the cover off the head to do this?


Thanks

Phil

Yes. It should be one screw, that only needs loosening, and is probably
on the bottom of the cover. If you can find the most awkward place for
a screw to be located, that's where it will be! Once it's loose, the
cover should slide directly away from the valve, revealing the motor,
wires, and switch.


Thanks Davey

I'll do my limbering up exercises ready for attempting to contort myself
(probably upside down) into the smallest space in the airing cupboard,
then moan cos the exertion has caused my glasses to steam up so I can't
see the hot water cylinder let alone a screw in the most inaccessible
recess possible.

Phil

Unclip the head off the valve first?

thescullster wrote:
Hi Bob

I don't believe the demand for heat signal can be reaching the boiler.
It has behaved fine serving the hot water circuit over summer and reacts
correctly when upstairs stat calls for heat.
yebbut the demand signal must be getting through as you said the
downstairs rads did heat up to start with? So the demand signal is
getting interrupted after a while.

Bob

On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has 3
motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil

I think from reading the discussion so far, that you're on your way to
fixing it.

Just to recap on the way in which an S/S+ Plan system works.

Each zone has a 2-port zone valve driven by a programmer plus stat (or
programmable stat). When there is a demand in a particular zone, its
zone valve opens.

Each zone valve has some auxiliary contacts which close when the valve
is fully open. These are wired in parallel, and are used to switch on
the boiler and pump. The boiler and pump will run when any one or more
zones are calling for heat, but only those zones whose valves are open
will get hot.

In your case, the troublesome zone's valve is opening but its contacts
are not switching the boiler and pump on - so that zone is only heated
when another zone is calling for heat at the same time.

There are 3 possible causes for this problem - starting with the most
likely:
1. The zone valve's microswitch has failed
2. The mechanical (wet) part of the valve has become partially jammed,
allowing the valve to open enough to allow water to flow but not enough
to operate the microswitch
3. A wire has become detached in the parallel microswitch circuit

Swapping two of the actuators without disturbing the wiring should
enable you to home in on the problem. [Remember you will need to
generate a demand for upstairs to test the downstairs circuit, and vice
versa while swapped]. Whilst you have the actuators off, check the valve
spindles to make sure that they turn freely. I suspect that they will,
and that the problem will transfer to the other zone - indicating that
the mircoswitch isn't switching.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Wed, 5 Oct 2016 20:46:21 +0100
Bob Minchin wrote:

thescullster wrote:
Hi Bob

I don't believe the demand for heat signal can be reaching the
boiler. It has behaved fine serving the hot water circuit over
summer and reacts correctly when upstairs stat calls for heat.
yebbut the demand signal must be getting through as you said the
downstairs rads did heat up to start with? So the demand signal is
getting interrupted after a while.

Bob

That may be the valve opening, and the heat already in the boiler
getting used up, but because the boiler is not getting a 'Run' signal,
the heat runs out. A failed valve microswitch would fit this
scenario.

Maybe.

--
Davey.

On 06/10/2016 00:02, Roger Mills wrote:
On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has 3
motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil

I think from reading the discussion so far, that you're on your way to
fixing it.

Just to recap on the way in which an S/S+ Plan system works.

Each zone has a 2-port zone valve driven by a programmer plus stat (or
programmable stat). When there is a demand in a particular zone, its
zone valve opens.

Each zone valve has some auxiliary contacts which close when the valve
is fully open. These are wired in parallel, and are used to switch on
the boiler and pump. The boiler and pump will run when any one or more
zones are calling for heat, but only those zones whose valves are open
will get hot.

In your case, the troublesome zone's valve is opening but its contacts
are not switching the boiler and pump on - so that zone is only heated
when another zone is calling for heat at the same time.

There are 3 possible causes for this problem - starting with the most
likely:
1. The zone valve's microswitch has failed
2. The mechanical (wet) part of the valve has become partially jammed,
allowing the valve to open enough to allow water to flow but not enough
to operate the microswitch
3. A wire has become detached in the parallel microswitch circuit

Swapping two of the actuators without disturbing the wiring should
enable you to home in on the problem. [Remember you will need to
generate a demand for upstairs to test the downstairs circuit, and vice
versa while swapped]. Whilst you have the actuators off, check the valve
spindles to make sure that they turn freely. I suspect that they will,
and that the problem will transfer to the other zone - indicating that
the mircoswitch isn't switching.

Hi Roger

Thanks for the clear and concise synopsis.
Looks like the issue was No 2 above, but see separate post.

Phil

On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack of
heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it has
3 motorised valves, one for hot water, one for upstairs heating and one
for downstairs heating.
These are controlled by a tank stat and timer for the hot water and two
Honeywell programmable wireless stats for the separate upstairs and
downstairs heating.

The issue seems to be when the downstairs stat only is calling for heat.
It looks like the radiators are heated for a short while, but then not.
The stat is calling for heat and this is indicated as received by a
green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download here,
the most relevant being the first. The valves are labelled. But as the
system has generally been working fine for ten years, the actual layout
is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one being
towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil


Thanks to all responders on this.

Took the cover off the downstairs heating motorised valve and called for
heat on that circuit. The motor rotated but stopped before the actuator
tab reached the micro switch - presumably this is down to sticky valve
internals.
So I "helped it" through the rest of its travel with a broggle from a
screwdriver. The pump and boiler fired up fine, so microswitch OK.
Tried raising and lowering stat temperature to see how it behaved and
the motor/actuator tab now travels far enough to make microswitch
contact unaided. Heating came on fine this morning.

One additional comment - moveable wireless stats are useful here cos I
could be increasing temperature for downstairs (calling for heat) while
sat in front of the valve in the airing cupboard upstairs.


Cheers guys

Phil

On Thu, 06 Oct 2016 09:09:29 +0100
thescullster wrote:

On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack
of heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it
has 3 motorised valves, one for hot water, one for upstairs heating
and one for downstairs heating.
These are controlled by a tank stat and timer for the hot water and
two Honeywell programmable wireless stats for the separate upstairs
and downstairs heating.

The issue seems to be when the downstairs stat only is calling for
heat. It looks like the radiators are heated for a short while, but
then not. The stat is calling for heat and this is indicated as
received by a green light on the base station in the airing
cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download
here, the most relevant being the first. The valves are labelled.
But as the system has generally been working fine for ten years,
the actual layout is probably not too relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one
being towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil


Thanks to all responders on this.

Took the cover off the downstairs heating motorised valve and called
for heat on that circuit. The motor rotated but stopped before the
actuator tab reached the micro switch - presumably this is down to
sticky valve internals.
So I "helped it" through the rest of its travel with a broggle from a
screwdriver. The pump and boiler fired up fine, so microswitch OK.
Tried raising and lowering stat temperature to see how it behaved and
the motor/actuator tab now travels far enough to make microswitch
contact unaided. Heating came on fine this morning.

One additional comment - moveable wireless stats are useful here cos
I could be increasing temperature for downstairs (calling for heat)
while sat in front of the valve in the airing cupboard upstairs.


Cheers guys

Phil






Glad you got it sorted out. And you now know the way around your
heating system! Make some sketches, piping and wiring, so you have a
ready reference for the next time (not 'if', but 'when' there is a next
time).

--
Davey.

On 06/10/2016 09:09, thescullster wrote:

Took the cover off the downstairs heating motorised valve and called for
heat on that circuit. The motor rotated but stopped before the actuator
tab reached the micro switch - presumably this is down to sticky valve
internals.
So I "helped it" through the rest of its travel with a broggle from a
screwdriver. The pump and boiler fired up fine, so microswitch OK.
Tried raising and lowering stat temperature to see how it behaved and
the motor/actuator tab now travels far enough to make microswitch
contact unaided. Heating came on fine this morning.

My experience with sticky valves is:

1. They jam up during the summer, when there's no demand for heat.
2. Once eased, they tend to get regular use during the winter, and keep
going until they jam up again the following summer.
3. Eventually, they jam more and take more easing, at which point you
end up replacing them, anyway.

Just my 2p worth.

pamela Wrote in message:
On 09:09 6 Oct 2016, thescullster wrote:

On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding
lack of heat to ground floor.

The system is an open vented S Plan Plus (I think).
Essentially it has 3 motorised valves, one for hot water, one
for upstairs heating and one for downstairs heating.
These are controlled by a tank stat and timer for the hot water
and two Honeywell programmable wireless stats for the separate
upstairs and downstairs heating.

The issue seems to be when the downstairs stat only is calling
for heat. It looks like the radiators are heated for a short
while, but then not. The stat is calling for heat and this is
indicated as received by a green light on the base station in
the airing cupboard.

If I then bring in demand for the upstairs heating circuit,
both upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for
download here, the most relevant being the first. The valves
are labelled. But as the system has generally been working
fine for ten years, the actual layout is probably not too
relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water
one being towards the back of the cupboard horixontally
mounted.

Can anyone can suggest the cause, diagnosis and fix method
please?


Thanks


Phil


Thanks to all responders on this.

Took the cover off the downstairs heating motorised valve and
called for heat on that circuit. The motor rotated but stopped
before the actuator tab reached the micro switch - presumably
this is down to sticky valve internals.
So I "helped it" through the rest of its travel with a broggle
from a screwdriver.

What's a broggle?

The pump and boiler fired up fine, so
microswitch OK. Tried raising and lowering stat temperature to
see how it behaved and the motor/actuator tab now travels far
enough to make microswitch contact unaided. Heating came on
fine this morning.

One additional comment - moveable wireless stats are useful here
cos I could be increasing temperature for downstairs (calling
for heat) while sat in front of the valve in the airing cupboard
upstairs.


Cheers guys

Phil


A broggle - a bit of a poke around
To broggle - the act of poking around with a broggler
A broggler - a tapered steel hand tool with handle usually used to
align holes of mating parts during assembly

All probably colloquial Yorkshire terms picked up during
engineering apprentice days.

Phil

--


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On Thu, 06 Oct 2016 21:52:56 +0100, TheChief wrote:

pamela Wrote in message:
On 09:09 6 Oct 2016, thescullster wrote:

On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding lack
of heat to ground floor.

The system is an open vented S Plan Plus (I think). Essentially it
has 3 motorised valves, one for hot water, one for upstairs heating
and one for downstairs heating.
These are controlled by a tank stat and timer for the hot water and
two Honeywell programmable wireless stats for the separate upstairs
and downstairs heating.

The issue seems to be when the downstairs stat only is calling for
heat. It looks like the radiators are heated for a short while, but
then not. The stat is calling for heat and this is indicated as
received by a green light on the base station in the airing cupboard.

If I then bring in demand for the upstairs heating circuit, both
upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for download
here, the most relevant being the first. The valves are labelled.
But as the system has generally been working fine for ten years, the
actual layout is probably not too relevant.

http://a360.co/2e0Uk8r http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water one
being towards the back of the cupboard horixontally mounted.

Can anyone can suggest the cause, diagnosis and fix method please?


Thanks


Phil


Thanks to all responders on this.

Took the cover off the downstairs heating motorised valve and called
for heat on that circuit. The motor rotated but stopped before the
actuator tab reached the micro switch - presumably this is down to
sticky valve internals.
So I "helped it" through the rest of its travel with a broggle from a
screwdriver.

What's a broggle?

The pump and boiler fired up fine, so microswitch OK. Tried raising
and lowering stat temperature to see how it behaved and the
motor/actuator tab now travels far enough to make microswitch contact
unaided. Heating came on fine this morning.

One additional comment - moveable wireless stats are useful here cos I
could be increasing temperature for downstairs (calling for heat)
while sat in front of the valve in the airing cupboard upstairs.


Cheers guys

Phil


A broggle - a bit of a poke around To broggle - the act of poking around
with a broggler A broggler - a tapered steel hand tool with handle
usually used to
align holes of mating parts during assembly

Ah, I get your drift.

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On 06/10/2016 23:36, Bob Eager wrote:

align holes of mating parts during assembly

Ah, I get your drift.

Would that be classed as a punchline?

On Fri, 07 Oct 2016 00:08:23 +0100, Pet @ www.gymratz.co.uk ;¬) wrote:

On 06/10/2016 23:36, Bob Eager wrote:

align holes of mating parts during assembly

Ah, I get your drift.

Would that be classed as a punchline?

Tool misuse if so!


--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On 06/10/16 21:52, TheChief wrote:
pamela Wrote in message:
On 09:09 6 Oct 2016, thescullster wrote:

On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding
lack of heat to ground floor.

The system is an open vented S Plan Plus (I think).
Essentially it has 3 motorised valves, one for hot water, one
for upstairs heating and one for downstairs heating.
These are controlled by a tank stat and timer for the hot water
and two Honeywell programmable wireless stats for the separate
upstairs and downstairs heating.

The issue seems to be when the downstairs stat only is calling
for heat. It looks like the radiators are heated for a short
while, but then not. The stat is calling for heat and this is
indicated as received by a green light on the base station in
the airing cupboard.

If I then bring in demand for the upstairs heating circuit,
both upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for
download here, the most relevant being the first. The valves
are labelled. But as the system has generally been working
fine for ten years, the actual layout is probably not too
relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water
one being towards the back of the cupboard horixontally
mounted.

Can anyone can suggest the cause, diagnosis and fix method
please?


Thanks


Phil


Thanks to all responders on this.

Took the cover off the downstairs heating motorised valve and
called for heat on that circuit. The motor rotated but stopped
before the actuator tab reached the micro switch - presumably
this is down to sticky valve internals.
So I "helped it" through the rest of its travel with a broggle
from a screwdriver.

What's a broggle?

The pump and boiler fired up fine, so
microswitch OK. Tried raising and lowering stat temperature to
see how it behaved and the motor/actuator tab now travels far
enough to make microswitch contact unaided. Heating came on
fine this morning.

One additional comment - moveable wireless stats are useful here
cos I could be increasing temperature for downstairs (calling
for heat) while sat in front of the valve in the airing cupboard
upstairs.


Cheers guys

Phil


A broggle - a bit of a poke around
To broggle - the act of poking around with a broggler
A broggler - a tapered steel hand tool with handle usually used to
align holes of mating parts during assembly


According to te dictionary

a brog, a pointed steel instrument like an awl
To brog or broggle. To pierce.


All probably colloquial Yorkshire terms picked up during
engineering apprentice days.

Phil



--
Religion is regarded by the common people as true, by the wise as
foolish, and by the rulers as useful.

(Seneca the Younger, 65 AD)

The Natural Philosopher Wrote in message:
On 06/10/16 21:52, TheChief wrote:
pamela Wrote in message:
On 09:09 6 Oct 2016, thescullster wrote:

On 05/10/2016 09:23, thescullster wrote:
Hi all

Hoping someone will be able to confirm my suspicions regarding
lack of heat to ground floor.

The system is an open vented S Plan Plus (I think).
Essentially it has 3 motorised valves, one for hot water, one
for upstairs heating and one for downstairs heating.
These are controlled by a tank stat and timer for the hot water
and two Honeywell programmable wireless stats for the separate
upstairs and downstairs heating.

The issue seems to be when the downstairs stat only is calling
for heat. It looks like the radiators are heated for a short
while, but then not. The stat is calling for heat and this is
indicated as received by a green light on the base station in
the airing cupboard.

If I then bring in demand for the upstairs heating circuit,
both upstairs and downstairs get hot.

There are a couple of photos of the valves and piping for
download here, the most relevant being the first. The valves
are labelled. But as the system has generally been working
fine for ten years, the actual layout is probably not too
relevant.

http://a360.co/2e0Uk8r
http://a360.co/2dwjwkr

The two valves in plain sight are for heating, the hot water
one being towards the back of the cupboard horixontally
mounted.

Can anyone can suggest the cause, diagnosis and fix method
please?


Thanks


Phil


Thanks to all responders on this.

Took the cover off the downstairs heating motorised valve and
called for heat on that circuit. The motor rotated but stopped
before the actuator tab reached the micro switch - presumably
this is down to sticky valve internals.
So I "helped it" through the rest of its travel with a broggle
from a screwdriver.

What's a broggle?

The pump and boiler fired up fine, so
microswitch OK. Tried raising and lowering stat temperature to
see how it behaved and the motor/actuator tab now travels far
enough to make microswitch contact unaided. Heating came on
fine this morning.

One additional comment - moveable wireless stats are useful here
cos I could be increasing temperature for downstairs (calling
for heat) while sat in front of the valve in the airing cupboard
upstairs.


Cheers guys

Phil


A broggle - a bit of a poke around
To broggle - the act of poking around with a broggler
A broggler - a tapered steel hand tool with handle usually used to
align holes of mating parts during assembly


According to te dictionary

a brog, a pointed steel instrument like an awl
To brog or broggle. To pierce.


All probably colloquial Yorkshire terms picked up during
engineering apprentice days.

Phil



--
Religion is regarded by the common people as true, by the wise as
foolish, and by the rulers as useful.

(Seneca the Younger, 65 AD)



Wow, never knew there was a plausible root to that word!

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