Hi,

The programmer that controls my central heating and hot water fails to communicate with the boiler and the boiler is continually 'ON'

The programmer is set at 'OFF' but the boiler still fires

The RET Electronic Room Thermostat that controls the central heating also fails to switch the boiler off even when turned fully down.

Because of this my central heating is continually 'on' and the thermostat fails to switch do anything in controlling the room temp as the boiler fails to switch off.

It has been suggested that I have a faulty motorised valve which is stuck in the 'on' position.

I assume that the motorised valve operating the central heating may be faulty.

There seems to be 2 motorised valves beside my water tank:-

1 - Synchron HPA2 Actuator/HPV26 valve(plastic box/white cover)
2 - Synchron 272848 Honeywell Motorised valve(metal box)

But which valve of the two is faulty?

1 is situated just above and in line with the pump and feeds into the top of the cylinder tank

2 is situated off of the main pump and and then travels down to the ground floor.

I guess that 2 is the one that controls the central heating?

All the wires that serve both valves go into a junction box so it is easy to isolate each valve but which one?

Will changing just the actuator resolve the problem because having had both actuators off each valve appears to turn except that 2 valve is what I could say a little stiff and jerky.

Will I have to drain the system?

There appears to be alot of 'stop taps' above and below each valve which sould facilitate removing of the valve.

I am tempted to just change the actuator!!

What does anyone think?

please advise

Cheers

Diezel

On Sat, 26 Aug 2006 02:35:29 +0100, diezeltruck wrote:

Hi,

The programmer that controls my central heating and hot water fails to
communicate with the boiler and the boiler is continually 'ON'

Do a google for 'S plan'. You should be able to come up with wiring
diagrams for all the common variations of heating system.

The programmer is set at 'OFF' but the boiler still fires

Wiring mistake, possibly

The RET Electronic Room Thermostat that controls the central heating
also fails to switch the boiler off even when turned fully down.

Wiring mistake, possibly

Because of this my central heating is continually 'on' and the
thermostat fails to switch do anything in controlling the room temp as
the boiler fails to switch off.

It has been suggested that I have a faulty motorised valve which is
stuck in the 'on' position.

That alone won't give rise to the symptoms you describe. If the system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.

I assume that the motorised valve operating the central heating may be
faulty.

There seems to be 2 motorised valves beside my water tank:-

1 - Synchron HPA2 Actuator/HPV26 valve(plastic box/white cover)
2 - Synchron 272848 Honeywell Motorised valve(metal box)

But which valve of the two is faulty?

1 is situated just above and in line with the pump and feeds into the
top of the cylinder tank

2 is situated off of the main pump and and then travels down to the
ground floor.

I guess that 2 is the one that controls the central heating?

All the wires that serve both valves go into a junction box so it is
easy to isolate each valve but which one?

Will changing just the actuator resolve the problem because having had
both actuators off each valve appears to turn except that 2 valve is
what I could say a little stiff and jerky.

Will I have to drain the system?

There appears to be alot of 'stop taps' above and below each valve
which sould facilitate removing of the valve.

I am tempted to just change the actuator!!

What does anyone think?

Start with the junction box if you're happy to investigate the wiring.


--
the dot wanderer at tesco dot net

The message
from The Wanderer contains these words:

It has been suggested that I have a faulty motorised valve which is
stuck in the 'on' position.

That alone won't give rise to the symptoms you describe. If the system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.

I don't think that follows. Surely the microswitch on the valve is fed
from the permanent live and the controller provides a switched live for
the thermostat. (That is certainly the way my controller should be
wired).

If the system worked properly once and the wiring has not been disturbed
a miss-wiring fault should not be present.

To the OP if the valve is difficult to move then that is the likely
culprit but it is the wet part that is at fault so you will have to
change the whole unit. The actuator can be tested easily enough by
seeing if the symptoms persist while the actuator is mechanically
disconnected to the valve which should, if faulty, remain open when the
actuator is disconnected. If the actuator is not faulty the thermostat
should then control the firing of the boiler.

--
Roger Chapman

diezeltruck wrote:
Hi,

The programmer that controls my central heating and hot water fails to
communicate with the boiler and the boiler is continually 'ON'

The programmer is set at 'OFF' but the boiler still fires

The RET Electronic Room Thermostat that controls the central heating
also fails to switch the boiler off even when turned fully down.

Because of this my central heating is continually 'on' and the
thermostat fails to switch do anything in controlling the room temp as
the boiler fails to switch off.

It has been suggested that I have a faulty motorised valve which is
stuck in the 'on' position.

I assume that the motorised valve operating the central heating may be
faulty.

There seems to be 2 motorised valves beside my water tank:-

1 - Synchron HPA2 Actuator/HPV26 valve(plastic box/white cover)
2 - Synchron 272848 Honeywell Motorised valve(metal box)

But which valve of the two is faulty?

Either.
They are wired 'or'

1 is situated just above and in line with the pump and feeds into the
top of the cylinder tank

2 is situated off of the main pump and and then travels down to the
ground floor.

I guess that 2 is the one that controls the central heating?

All the wires that serve both valves go into a junction box so it is
easy to isolate each valve but which one?

Will changing just the actuator resolve the problem because having had
both actuators off each valve appears to turn except that 2 valve is
what I could say a little stiff and jerky.


That one (in an Andy voice)

Will I have to drain the system?

Maybe. Take the actuatoir off and try wiggling the valve stem

Sometimes swarf or scale causes them to jam. If you can free it up
enough the actuator motor may be able to move it again, or if its burnt
out, new actuator.


There appears to be alot of 'stop taps' above and below each valve
which sould facilitate removing of the valve.

I am tempted to just change the actuator!!


Certainly remove it and check the spindle moves. Mine did this and only
needed a new motorised bit.

If you disconnect the actuator switch contacts temporarily, at least the
boiler won;t come on all the time.


What does anyone think?

please advise

Cheers

Diezel

The Wanderer wrote:
On Sat, 26 Aug 2006 02:35:29 +0100, diezeltruck wrote:

Hi,

The programmer that controls my central heating and hot water fails to
communicate with the boiler and the boiler is continually 'ON'

Do a google for 'S plan'. You should be able to come up with wiring
diagrams for all the common variations of heating system.

The programmer is set at 'OFF' but the boiler still fires

Wiring mistake, possibly

The RET Electronic Room Thermostat that controls the central heating
also fails to switch the boiler off even when turned fully down.

Wiring mistake, possibly

Because of this my central heating is continually 'on' and the
thermostat fails to switch do anything in controlling the room temp as
the boiler fails to switch off.

It has been suggested that I have a faulty motorised valve which is
stuck in the 'on' position.

That alone won't give rise to the symptoms you describe. If the system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.


Completely WRONG. The controller does not have the power to drive the
boiler. The controller drives the thermostat and the valve motor: The
switches on the valve body control the boiler. That is why they are there.

Roger wrote:
The message
from The Wanderer contains these words:

It has been suggested that I have a faulty motorised valve which is
stuck in the 'on' position.

That alone won't give rise to the symptoms you describe. If the system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.

I don't think that follows. Surely the microswitch on the valve is fed
from the permanent live and the controller provides a switched live for
the thermostat. (That is certainly the way my controller should be
wired).

It's wired from permanent live on the switched fused spur that should
run the whole heating system..


If the system worked properly once and the wiring has not been disturbed
a miss-wiring fault should not be present.

To the OP if the valve is difficult to move then that is the likely
culprit but it is the wet part that is at fault so you will have to
change the whole unit. The actuator can be tested easily enough by
seeing if the symptoms persist while the actuator is mechanically
disconnected to the valve which should, if faulty, remain open when the
actuator is disconnected. If the actuator is not faulty the thermostat
should then control the firing of the boiler.

On Sat, 26 Aug 2006 10:24:40 +0100, The Natural Philosopher wrote:

The Wanderer wrote:
On Sat, 26 Aug 2006 02:35:29 +0100, diezeltruck wrote:

Hi,

The programmer that controls my central heating and hot water fails to
communicate with the boiler and the boiler is continually 'ON'

Do a google for 'S plan'. You should be able to come up with wiring
diagrams for all the common variations of heating system.

The programmer is set at 'OFF' but the boiler still fires

Wiring mistake, possibly

The RET Electronic Room Thermostat that controls the central heating
also fails to switch the boiler off even when turned fully down.

Wiring mistake, possibly

Because of this my central heating is continually 'on' and the
thermostat fails to switch do anything in controlling the room temp as
the boiler fails to switch off.

It has been suggested that I have a faulty motorised valve which is
stuck in the 'on' position.

That alone won't give rise to the symptoms you describe. If the system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.


Completely WRONG.

********. As usual, you pontificate on things with such conviction , and it
is *you* who is wrong. Do your homework, and take a google for 'S plan'
wiring diagrams. The info is out there if you take a look for it, it might
save you from looking so bloody stupid in future.

--
the dot wanderer at tesco dot net

The message
from The Natural Philosopher contains these words:

That alone won't give rise to the symptoms you describe. If the
system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.

I don't think that follows. Surely the microswitch on the valve is fed
from the permanent live and the controller provides a switched live for
the thermostat. (That is certainly the way my controller should be
wired).

It's wired from permanent live on the switched fused spur that should
run the whole heating system..

How come? The microswitch only closes when the thermostat powers up the
actuator.

--
Roger Chapman

--

Sparks...
(Not an electrician)
"Roger" wrote in message
k...
The message
from The Natural Philosopher contains these words:

That alone won't give rise to the symptoms you describe. If the
system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.

I don't think that follows. Surely the microswitch on the valve is fed
from the permanent live and the controller provides a switched live for
the thermostat. (That is certainly the way my controller should be
wired).

It's wired from permanent live on the switched fused spur that should
run the whole heating system..

How come? The microswitch only closes when the thermostat powers up the
actuator.

Unless the actuator is faulty, has stuck on, one side of the microsowitch is
connected to the boiler, and the other is connected to a permanant live - I
am guessing the feed to the valve switch should be connected to the output
from the thermostat, and the other side of the thermostat is connected to
the output of the programmer?

Sparks...

On Sat, 26 Aug 2006 10:24:40 +0100, The Natural Philosopher wrote:

The Wanderer wrote:

snip

That alone won't give rise to the symptoms you describe. If the system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.


Completely WRONG. The controller does not have the power to drive the
boiler. The controller drives the thermostat and the valve motor: The
switches on the valve body control the boiler. That is why they are there.

Yes, you are correct, I had mis-read the wiring diagram I was looking at.

--
the dot wanderer at tesco dot net

In an earlier contribution to this discussion,
Roger wrote:


It's wired from permanent live on the switched fused spur that should
run the whole heating system..

How come? The microswitch only closes when the thermostat powers up
the actuator.

The microswitch is closed whenever the valve is open. The valve is opened by
a motor - when told to do so by the programmer and stat. It is closed by a
spring when the demand is removed.

HOWEVER, if the wet part of the valve jams open such that the return spring
is unable to close it, the microswitch remains closed, and the boiler
continues to fire - regardless of what the programmer and stat are doing.
--
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!

The message
from "Roger Mills" contains these words:

It's wired from permanent live on the switched fused spur that should
run the whole heating system..

How come? The microswitch only closes when the thermostat powers up
the actuator.

The microswitch is closed whenever the valve is open. The valve is
opened by
a motor - when told to do so by the programmer and stat. It is closed by a
spring when the demand is removed.

HOWEVER, if the wet part of the valve jams open such that the return spring
is unable to close it, the microswitch remains closed, and the boiler
continues to fire - regardless of what the programmer and stat are doing.

I am not disputing that as a particular fault and, if you read my
earlier messages, that is exactly what I had previously suggested. What
I was challenging was the NTs suggestion that wiring the microswitch
that way was wrong as it would lead to the whole system being
permanently on. However it seems I may have misinterpreted what the NT
actually meant.

--
Roger Chapman

Roger wrote:
The message
from The Natural Philosopher contains these words:

That alone won't give rise to the symptoms you describe. If the
system has
been wired properly, then the controller overides any other auxiliary
switches (like the thermostat, the aux switches on the valves) in the
circuit.
I don't think that follows. Surely the microswitch on the valve is fed
from the permanent live and the controller provides a switched live for
the thermostat. (That is certainly the way my controller should be
wired).

It's wired from permanent live on the switched fused spur that should
run the whole heating system..

How come? The microswitch only closes when the thermostat powers up the
actuator.

Correct. Your point being?

Sparks wrote:

Unless the actuator is faulty, has stuck on, one side of the
microsowitch is connected to the boiler, and the other is connected to
a permanant live - I am guessing the feed to the valve switch should
be connected to the output from the thermostat, and the other side of
the thermostat is connected to the output of the programmer?

Correct. The live feeds the timer and the valve SWITCH. The valve MOTOR
is fed via the thermostat from the timer OUTPUT. The SWITCH OUTPUT feeds
the boiler.

Thanks Roger! You're confirmation of what i'd thought was right and the Wanderers advice was incorrect

How could it be a wiring problem if the sysem has been working for the last 8 years without any probs and no wiring altered?

Having removed the actuator attached to the valve and manually turned the valve using my fingers hopefully freeing it and replacing the actuator appears to have solved the issue.

I've been on hols for 3 weeks and the CH has been off causing the valve to seize up.

Turning the valve does appear to be a little stiff and jerky but hopefully now the system is up and running it should stay that way.

Thanks for your sound advice

Diezel

[QUOTE=Take the actuatoir off and try wiggling the valve stem

Sometimes swarf or scale causes them to jam. If you can free it up
enough the actuator motor may be able to move it again, or if its burnt
out, new actuator.


Brilliant Natural Philosopher t sure was swarf or scale causing valve to jam

cheers

Diezel

On Sun, 27 Aug 2006 01:10:24 +0100, diezeltruck wrote:

snip

Thanks Roger! You're confirmation of what i'd thought was right and the
Wanderers advice was incorrect

I did say in another post in this thread that I had misread the wiring
diagram.

--
the dot wanderer at tesco dot net

The message
from The Natural Philosopher contains these words:

It's wired from permanent live on the switched fused spur that should
run the whole heating system..

How come? The microswitch only closes when the thermostat powers up the
actuator.

Correct. Your point being?

Sorry about that. I thought you were saying that wiring the microswitch
that way would result in the heating being permanently on.

--
Roger Chapman