Hi,

I've just moved into a house that has an old Apollo Boiler, a Randall
922 controller and an ACL thermostat in the hall. Upstairs there is a
hot water cylinder with a cylinder stat, a pump and a diverter valve
(ACL IIRC).

Now, with the hot water off and the heating on nothing happens. The
controller clicks as if it is switching something but nothing happens at
the boiler and the radiators don't heat up. With the hot water on, the
boiler works and the radiators heat up. Playing with the thermostat in
the hall makes no difference as to whteher the boiler stops or starts.

So, any ideas as to how I can fix it? I'm not really sure where to start
investigating where the problem might be either. I know the hall stat
has electricity running to it as I checked that with my multimeter last
night, it just doesn't seem to do anything.

TIA.

--
Organoman.

On Tue, 04 Apr 2006 11:32:27 GMT, Organoman
wrote:

Hi,

I've just moved into a house that has an old Apollo Boiler, a Randall
922 controller and an ACL thermostat in the hall. Upstairs there is a
hot water cylinder with a cylinder stat, a pump and a diverter valve
(ACL IIRC).

Now, with the hot water off and the heating on nothing happens. The
controller clicks as if it is switching something but nothing happens at
the boiler and the radiators don't heat up. With the hot water on, the
boiler works and the radiators heat up. Playing with the thermostat in
the hall makes no difference as to whteher the boiler stops or starts.

So, any ideas as to how I can fix it? I'm not really sure where to start
investigating where the problem might be either. I know the hall stat
has electricity running to it as I checked that with my multimeter last
night, it just doesn't seem to do anything.

TIA.

This is a common situation with many simple installations of this
period. The boiler is on or off irrespective of what task it is doing,
particularly with Randall programmers. So there is no CH only setting,
the water is on all the time and the CH is on or off.

You should be able to tell because there should be a motorised
diverter valve in the system. This is the thing that the HW only
setting should be controlling. If you haven't got one, the HW switch
is for decoration only.

On Tue, 04 Apr 2006 12:21:16 GMT, EricP
wrote:

You can probably do a better check of the situation by looking at the
pipework from the boiler.

If there are four pipes coming out at the back for the water heating
and the CH then it likely that HW switch has never been intended to
work.

If there are only two pipes coming out of the bolier,(one usually
higher than the other), then you have a fully pumped system and should
have a diverter valve and the HW switch should work.

On Tue, 04 Apr 2006 11:32:27 GMT, Organoman
wrote:

Hi,

I've just moved into a house that has an old Apollo Boiler, a Randall
922 controller and an ACL thermostat in the hall. Upstairs there is a
hot water cylinder with a cylinder stat, a pump and a diverter valve
(ACL IIRC).

Now, with the hot water off and the heating on nothing happens. The
controller clicks as if it is switching something but nothing happens at
the boiler and the radiators don't heat up. With the hot water on, the
boiler works and the radiators heat up. Playing with the thermostat in
the hall makes no difference as to whteher the boiler stops or starts.

So, any ideas as to how I can fix it? I'm not really sure where to start
investigating where the problem might be either. I know the hall stat
has electricity running to it as I checked that with my multimeter last
night, it just doesn't seem to do anything.

TIA.

Sorry for the high Idiot Factor rating today. Read your post in a
hurry.

EricP wrote:



Sorry for the high Idiot Factor rating today. Read your post in a
hurry.

That's alright :-)

Just to make sure we're all clear tho, the HW switch works, it's the CH
switch that doesn't appear to be working. It does have a pump and there
is a diverter valve. There's also a stat that appears to be useless.

Oh, and I've just remembered one more thing. The stat has the red wire
(live) screwed into neutral and the black wire (neutral) plugged into
live. The earth is in the righ tplace but whetehr it is connected to
anythin gudeful is anyone's guess. According to the diagram on the back
of the stat cover, the live should be in live and the neutral in neutral
IYSWIM. So I've no idea what's going on there.

--
Organoman.

In an earlier contribution to this discussion,
Organoman wrote:

Hi,

I've just moved into a house that has an old Apollo Boiler, a Randall
922 controller and an ACL thermostat in the hall. Upstairs there is a
hot water cylinder with a cylinder stat, a pump and a diverter valve
(ACL IIRC).

Now, with the hot water off and the heating on nothing happens. The
controller clicks as if it is switching something but nothing happens
at the boiler and the radiators don't heat up. With the hot water on,
the boiler works and the radiators heat up. Playing with the
thermostat in the hall makes no difference as to whteher the boiler
stops or starts.
So, any ideas as to how I can fix it? I'm not really sure where to
start investigating where the problem might be either. I know the
hall stat has electricity running to it as I checked that with my
multimeter last night, it just doesn't seem to do anything.

TIA.

Has it ever worked properly to your knowledge?

It sounds as if you have got a Y-Plan system. The valve will almost
certainly *not* be a diverter valve, but will be a 3-port mid-position
valve - capable of providing HW only, CH only or both together. A diverter
valve provides one or the other but not both at the same time - so your
radiators wouldn't have been on when the hot water was heating.

In order to make a Y-Plan system work in CH-only mode, you *must* have a
HW-OFF connection on the programmer and a HW-satisfied (as well as HW
demand) connection on the cylinder thermostat. So, if it has *never* worked,
the chances are that it is wired incorrectly.

Have a look at the Y-Plan wiring in
http://content.honeywell.com/uk/homes/systems.htm to see how it *should* be
done. OK - that shows Honeywell kit and yours is Randall and ACL-Drayton -
but the principles are exactly the same.
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but not regularly monitored.

Roger Mills wrote:



Has it ever worked properly to your knowledge?


I'm afraid I don't know. I've only had the house for 3 weeks. The
GAS-ELEC tester reckoned the boiler and radiators were all fine. I'm
guessing they didn't actually test to see if it worked properly.

I'll take another look at the valve when I get home. it has a plastic
sliding switch that is quite loose. You can push it to the side and it
requires no pressure to move it.

Thanks.

--
Organoman.

In an earlier contribution to this discussion,
Organoman wrote:

Roger Mills wrote:



Has it ever worked properly to your knowledge?


I'm afraid I don't know. I've only had the house for 3 weeks. The
GAS-ELEC tester reckoned the boiler and radiators were all fine. I'm
guessing they didn't actually test to see if it worked properly.

I'll take another look at the valve when I get home. it has a plastic
sliding switch that is quite loose. You can push it to the side and it
requires no pressure to move it.

Thanks.

In that case, another possibility is that the valve is jammed in the
mid-position. If this is the case, as long as there's a HW demand the boiler
and pump will run and the radiators will get hot too. But as soon as it
needs to move into the CH-only mode, nothing will happen. It's only when the
valve moves *beyond* the mid position that a microswitch in the actuator
operates and switches the boiler on. If this doesn't happen - no CH!
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but not regularly monitored.

On Tue, 04 Apr 2006 13:08:31 GMT someone who may be Organoman
wrote this:-

Oh, and I've just remembered one more thing. The stat has the red wire
(live) screwed into neutral

How do you know it is live?

Is it screwed into a terminal marked N?

and the black wire (neutral)

How do you know it is neutral? It could well be a switched live (or
indeed a live) that has not been identified properly.

plugged into live.

Plugged into a terminal marked L?

According to the diagram on the back
of the stat cover, the live should be in live and the neutral in neutral
IYSWIM.

Assuming that the thermostat needs live and neutral connections,
some do, there is one more connection missing. That is the switched
live that tells the rest of the system whether the thermostat is
calling for heat or not.

If the system once worked properly then the valve is the likely
culprit. If it never worked properly then the wiring is probably the
culprit. I suggest tracing out the wiring carefully and comparing it
with the diagrams already referred to.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On Tue, 04 Apr 2006 13:08:31 GMT someone who may be Organoman
wrote this:-


Oh, and I've just remembered one more thing. The stat has the red wire
(live) screwed into neutral


How do you know it is live?

Is it screwed into a terminal marked N?


and the black wire (neutral)


How do you know it is neutral? It could well be a switched live (or
indeed a live) that has not been identified properly.


plugged into live.


Plugged into a terminal marked L?


According to the diagram on the back
of the stat cover, the live should be in live and the neutral in neutral
IYSWIM.


Assuming that the thermostat needs live and neutral connections,
some do, there is one more connection missing. That is the switched
live that tells the rest of the system whether the thermostat is
calling for heat or not.

If the system once worked properly then the valve is the likely
culprit. If it never worked properly then the wiring is probably the
culprit. I suggest tracing out the wiring carefully and comparing it
with the diagrams already referred to.



Yes, you're right, I made an daft assumption about the state of the
wires based on the colour of them. And yes, they are screwed into L and
N terminals. There is also a forth terminal that has nothing screwed
into it.

Unfortunately, as I mentioned in another reply, I have no idea if it's
always been like this or if it's a new problem. However, you and the
others who have posted replies have given me more than enough food for
thought and a great starting place for further investigation.

Thanks.

--
Organoman.

Organoman wrote:

Follow-up.

Had a look at the spaghetti wiring. It's quite messy and very hard to
figure out what's what. it does have a mid-position valve which does
actually have some resistance when the heating is on, so maybe it's not
borked after all. if I push the valve switch to the right, with some
force, I can hear a switch latching, but nothing else seems to happen.

I don't know if it's worrying or not, but the controller isn't earthed
and the earth cable is being used as a controller cable. A couple of the
other cable sin the bundle have been snipped short too.

Guess I'll just have to trawl the net for a suitable diagram or something.

--
Organoman.

On Wed, 05 Apr 2006 14:25:51 GMT someone who may be Organoman
wrote this:-

I don't know if it's worrying or not, but the controller isn't earthed

Something to sort out fairly quickly. If the rest of the earthing is
up to scratch it could be left a few weeks without too much danger.

and the earth cable is being used as a controller cable.

Illegal. However, something to sort out after the earthing. Replace
with cables with enough cores to allow for future possibilities.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54