Hi All

I put my radiaors on the other day for the first time this year.

Now the problem is that they stay hot all the time.

Looking at the web i think that i have a fully pumped system?

I have a big tank and a smaller expanaion tank in the loft.

My switch is a Switchmaster SM905. It does once or twice on hot water
and once or twice on CH.

For the last couple of days the CH switch has been in the off position
and the Hot water on continuois (as all summer) yet radiators are
still on.

I think my pump is staying on all the time but will it go on for the
hot water anyway? .

When i put a long metal rod to the pump from my ear, the sound remains
the same when i switch both switches from continuous to off ??.
(noisy).

The last time my heating was on was when i had to get some chap out to
fix it a few months ago as it just would not light (Baxi) . He said it
was clogged up. It did work ok after that.

As a further test i have just put CH continuous. Hot water on off and
then turned room thermostat (downstairs ) on & off. This DID start and
stop the Baxi??.

any ideas please.

On Sun, 26 Sep 2004 13:37:32 +0100, Andy Pandy
wrote:

Hi
A bit more info
I have just took another look and noticed a Drayton MID Position
actuator fitted th the valves ?? it has a small pushable lever on the
side of it. Which could have been pushed over the last few months?.

thanks

Andy

In an earlier contribution to this discussion,
Andy Pandy wrote:

On Sun, 26 Sep 2004 13:37:32 +0100, Andy Pandy
wrote:

Hi
A bit more info
I have just took another look and noticed a Drayton MID Position
actuator fitted th the valves ?? it has a small pushable lever on the
side of it. Which could have been pushed over the last few months?.

thanks

Andy

Your problem is probably in this area. The 3-port mid-position valve directs
hot water pumped from the boiler either to the hot water circuit (coil
inside the hot water cylinder) or to the heating circuit (radiators) or to
both at the same time - when in its mid position.

The valve in in two parts - the wet part and the electrical part. The wet
part is a sort of T-piece with a paddle inside which directs the flow. there
is a spindle sticking out of the top which, when rotated, moves the paddle
to one of 3 positions (HW, CH or Both). The electrical part (actuator) is
bolted to the top of the valve, and rotates the spindle to the appropriate
position depending on the programmer and room/tank stat status. [The lever
simply moves the valve to its mid position for system testing].

Most actuators have a spring return to the HW water position, and a motor to
turn the valve - against the spring - to the other positions. When it
arrives at either of the other two positions, microswitches operate in order
to ensure that the boiler and pump are turned on when needed.

Several things can go wrong with these valves, which may possibly explain
your symptoms. One is that the actuator simply gets confused. The cure for
this - and perhaps the first thing to try - is to remove *all* power from
the system - by turning it off at the FCU which feeds the whole heating
system - not just at the programmer. Allow the valve's spring return to move
it back to its "home" position, and then turn it on and try again. This can
sometimes work.

If this doesn't work, remove the actuator from the valve ** and make sure
that the spindle is free to rotate - if not with your finger and thumb, it
should move with only *light* pressure from a pair of pliers. [If it hasn't
been exercised for a while, it could have stuck in the mid-position. Moving
it to and fro should free it]
** most actuators can be removed from the valve without any water spillage -
but just a few are integral with the valve, and can't. Proceed with caution
until you are sure which sort you have got!

If the spindle moves freely, and the heating/hot water *still* don't behave
themselves, the actuator - particularly the mircroswitches inside could be
shot.

Anyway, check the 2 things described above, and come back for further advice
if needed.
--
Cheers,
Set Square
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On Sun, 26 Sep 2004 14:49:51 +0100, "Set Square"
wrote:



Hi

Several things can go wrong with these valves, which may possibly explain
your symptoms. One is that the actuator simply gets confused. The cure for
this - and perhaps the first thing to try - is to remove *all* power from
the system - by turning it off at the FCU which feeds the whole heating
system - not just at the programmer. Allow the valve's spring return to move
it back to its "home" position, and then turn it on and try again. This can
sometimes work.

If this doesn't work, remove the actuator from the valve ** and make sure
that the spindle is free to rotate - if not with your finger and thumb, it
should move with only *light* pressure from a pair of pliers. [If it hasn't
been exercised for a while, it could have stuck in the mid-position. Moving
it to and fro should free it]



If the spindle moves freely, and the heating/hot water *still* don't behave
themselves, the actuator - particularly the mircroswitches inside could be
shot.

The spindle moves freely with finger & thumb. Only moves 45 deg or so
(normal i presume)

After i took the actuator off I lay it on the floor as i played with
the Room Thermostat and the programmer.

I could see the lever on the side of it moving from W to M to H (does
not seem to go all the way to H ! ( I would asume H is to give
radiators heat, of which i have too much anyway) as I played around.
This would suggest that it is working so I have put it back on and now
have turned the power back on.

I hope that it was just confused or the spindle did just need some
assistance to free up.

I will post back to let you know.

Thank you for your reply.

Andy

In an earlier contribution to this discussion,
Andy Pandy wrote:


The spindle moves freely with finger & thumb. Only moves 45 deg or so
(normal i presume)

Did it move straight away, or did you have to free it?

I think some of these valves move 45 degrees either side of the mid
position - i.e. 90 degrees in all. Is that what you mean?

--
Cheers,
Set Square
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On Sun, 26 Sep 2004 18:45:21 +0100, "Set Square"
wrote:



Did it move straight away, or did you have to free it?

I think i felt a small resistance but I cannot be sure.

I has just put the heating on in my last post.

I then let the Rads heat up to max. I then turned the room thermostat
off 2 hrs ago (leaving the programmer set to CH Continuous, My next
step was to set this to off also, had the room stat not stopped the
hot rads).

Now my rads are cool and FCU (fused spare ? ) is on . Programmer is
set to HW cont, CH cont.

One point though,, my bathroom rad is still warm (only warm and not at
all the full normal temp). I think I have always had this with the
bathroom rad though.

Thank you so much for your indepth reply. you have solved my problem
(touch wood).

Andy

In an earlier contribution to this discussion,
Andy Pandy wrote:


One point though,, my bathroom rad is still warm (only warm and not at
all the full normal temp). I think I have always had this with the
bathroom rad though.

Are you saying that the bathroom rad is warm when the CH is off, and all
other rads are cold?

Does the bathroom rad get warm in the summer when the HW is on but the CH is
off? If so, it is possible that that it is connected into the HW circuit
rather than the CH circuit (or even possibily connected *before * the
mid-position valve so that it gets hot to warm the towels whenever the
boiler the running - whether for HW or CH or both. If you have had the HW
on after you turned the CH off and if this rad got warm as a result, this
could be a possible explanation.

--
Cheers,
Set Square
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On Sun, 26 Sep 2004 23:55:23 +0100, "Set Square"
wrote:



Are you saying that the bathroom rad is warm when the CH is off, and all
other rads are cold?

Yes it is always a bit warmer, sometimes warmer than others (as in on
and not just room temp of bath room when hot bath or shower has heated
room temp).

Does the bathroom rad get warm in the summer when the HW is on but the CH is
off?

yes


If so, it is possible that that it is connected into the HW circuit
rather than the CH circuit (or even possibily connected *before * the
mid-position valve so that it gets hot to warm the towels whenever the
boiler the running - whether for HW or CH or both. If you have had the HW
on after you turned the CH off and if this rad got warm as a result, this
could be a possible explanation.

Well the little I have learnt since the weekend tells me that the mid
position valve is fitted 3 foot from the boiler and there are two Ts
off before this, they are both going to exp tank , one 15mm and one 22
mm. (these measurements are from material on the web and my
understanding of my system!).

The pipes that go into the tank (cylinder) (hw circuit) ! from the
boiler go straight into it, the cylinder and boiler are only 2 feet
apart.

The rad in the Bathroom is the nearest Rad physically. and has thin
pipes into floor (10 mm ?) but there are no pipes of this size in the
vicinity of valve,boiler or cylinder.

As a test I just checked rad in bathroom which was cold. I the turned
hot tap on for 2 mins to start boiler and pump (ch off, hw continuous
on programmer and room thermostat in living room off, all other rads
cold)

and the pipe going into rad got piping hot though the rad will just
get warm and stay that way.

could the mid valve be open a touch ? enough to push a touch of hot
water to this rad but not enough to get it piping hot or spread to
other rads??


Andy

In an earlier contribution to this discussion,
Andy Pandy wrote:


As a test I just checked rad in bathroom which was cold. I the turned
hot tap on for 2 mins to start boiler and pump (ch off, hw continuous
on programmer and room thermostat in living room off, all other rads
cold)

and the pipe going into rad got piping hot though the rad will just
get warm and stay that way.

could the mid valve be open a touch ? enough to push a touch of hot
water to this rad but not enough to get it piping hot or spread to
other rads??


It's more likely that you've got reverse circulation - or single pipe
circulation up the return pipe. When this happens, how hot is the CH outlet
pipe from the 3-port valve? [I would expect it to be warm for a foot or so,
purely by conduction - but to be cold beyond that unless the valve *does*
have an internal leak.

If you want to investigate further, you may need to take up one or two
floorboards to see exactly where the pipes go!

What I would expect is the following:
Flow pipe (22 or 28mm) coming from boiler. Connections for expansion and
fill pipes, then the pump, then the inlet to the 3-port valve.

One outlet from the 3-port valve (22mm) goes to the top of the heating coil
in the hot water cylinder.

The other 22mm outlet feeds the radiators, with individual radiator feed
pipes tee'd off it. [It may also split into 2 or more branches, depending on
the layout of your house]

The returns from the radiators should also all be combined into a single
(probably 22mm) pipe which, in turn, joins with the return from the coil in
the hot water cylinder before returning to the boiler. There may be a
'balancing' gate valve in the return from the hot water coil before it
combines with the CH return.

What you should *not* have, is any radiator returns connected into the
boiler return pipe *after* the point where the HW return joins it.

Hope this makes sense!
--
Cheers,
Set Square
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On Tue, 28 Sep 2004 10:11:07 +0100, "Set Square"
wrote:

In an earlier contribution to this discussion,
Andy Pandy wrote:


As a test I just checked rad in bathroom which was cold. I the turned
hot tap on for 2 mins to start boiler and pump (ch off, hw continuous
on programmer and room thermostat in living room off, all other rads
cold)

and the pipe going into rad got piping hot though the rad will just
get warm and stay that way.

could the mid valve be open a touch ? enough to push a touch of hot
water to this rad but not enough to get it piping hot or spread to
other rads??


It's more likely that you've got reverse circulation - or single pipe
circulation up the return pipe. When this happens, how hot is the CH outlet
pipe from the 3-port valve? [I would expect it to be warm for a foot or so,
purely by conduction - but to be cold beyond that unless the valve *does*
have an internal leak.

If you want to investigate further, you may need to take up one or two
floorboards to see exactly where the pipes go!

What I would expect is the following:
Flow pipe (22 or 28mm) coming from boiler. Connections for expansion and
fill pipes, then the pump, then the inlet to the 3-port valve.

One outlet from the 3-port valve (22mm) goes to the top of the heating coil
in the hot water cylinder.

The other 22mm outlet feeds the radiators, with individual radiator feed
pipes tee'd off it. [It may also split into 2 or more branches, depending on
the layout of your house]

The returns from the radiators should also all be combined into a single
(probably 22mm) pipe which, in turn, joins with the return from the coil in
the hot water cylinder before returning to the boiler. There may be a
'balancing' gate valve in the return from the hot water coil before it
combines with the CH return.

What you should *not* have, is any radiator returns connected into the
boiler return pipe *after* the point where the HW return joins it.

Hope this makes sense!

Will print and digest. just wanna let ya know that i have the info
thanks. Will reply soon.

Andy

On Tue, 28 Sep 2004 10:11:07 +0100, "Set Square"
wrote:

It's more likely that you've got reverse circulation - or single pipe
circulation up the return pipe. When this happens, how hot is the CH outlet
pipe from the 3-port valve? [I would expect it to be warm for a foot or so,
purely by conduction - but to be cold beyond that unless the valve *does*
have an internal leak.

Well the bath room Rad is about 6 feet away and always feels warm.

If you want to investigate further, you may need to take up one or two
floorboards to see exactly where the pipes go!

What I would expect is the following:
Flow pipe (22 or 28mm) coming from boiler. Connections for expansion and
fill pipes, then the pump, then the inlet to the 3-port valve.

yes



One outlet from the 3-port valve (22mm) goes to the top of the heating coil
in the hot water cylinder.

yes

The other 22mm outlet feeds the radiators, with individual radiator feed
pipes tee'd off it. [It may also split into 2 or more branches, depending on
the layout of your house]

The returns from the radiators should also all be combined into a single
(probably 22mm) pipe which, in turn, joins with the return from the coil in
the hot water cylinder before returning to the boiler. There may be a
'balancing' gate valve in the return from the hot water coil before it
combines with the CH return.

Yes (no gate valve)


What you should *not* have, is any radiator returns connected into the
boiler return pipe *after* the point where the HW return joins it.

No i have not

Hope this makes sense!

I can live with the Rad getting warm. Thank you once again for your
reply.

This is a very interesting topic and i feel that i have gained some
knowlege about heating systems in the last week.

Andy.