My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.


--
Chris Green
·

On Tue, 24 Feb 2015 19:05:35 +0000, wrote:

My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.

Another explanation could be a mictoswitch in a motorised valve
permanently closed.
Does the controller operate make the motors open and close the
valve(s)?

--

Graham.

%Profound_observation%

Graham. wrote:
On Tue, 24 Feb 2015 19:05:35 +0000, wrote:

My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.

Another explanation could be a mictoswitch in a motorised valve
permanently closed.
Does the controller operate make the motors open and close the
valve(s)?

That's a thought, thanks, I didn't really have time to see if the
valves were operating the last time I was there.

--
Chris Green
·

On 24/02/2015 19:05, wrote:
My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.


You haven't told us what other controls there are. Are there any
motorised valves? If there are two 2-port valves, it will be an S-Plan
system. In such as system, the programmer and room/cylinder stats drive
the valves and, once the valves are open, auxiliary switches within the
valves turn on the boiler and pump.

If one of these switches fails closed or, in some cases, if one of the
valves fails open, the boiler will run even if there is no demand from
the programmer and stats. Could this be your daughter's problem?
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

Roger Mills wrote:
On 24/02/2015 19:05, wrote:
My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.


You haven't told us what other controls there are. Are there any
motorised valves? If there are two 2-port valves, it will be an S-Plan
system. In such as system, the programmer and room/cylinder stats drive
the valves and, once the valves are open, auxiliary switches within the
valves turn on the boiler and pump.

Yes, there are motorised valves, three I think (the H37 has two
heating programs and a hot water program).


If one of these switches fails closed or, in some cases, if one of the
valves fails open, the boiler will run even if there is no demand from
the programmer and stats. Could this be your daughter's problem?

It could very well be this, thanks, I will check the switches
associated with the motorised valves.

--
Chris Green
·

On Tuesday, February 24, 2015 at 7:16:04 PM UTC, wrote:
My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.

Get your multimeter out & find out. Does the programmer's 'CH on' wire stay live or not?


NT

wrote in message
...
On Tuesday, February 24, 2015 at 7:16:04 PM UTC, wrote:
My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.

Get your multimeter out & find out. Does the programmer's 'CH on' wire
stay live or not?

And how do you do that?

Remove the programmer from the base plate and then there is no permanent
live to test the switched live.



--
Adam

On 24/02/2015 21:42, ARW wrote:
wrote in message
...
On Tuesday, February 24, 2015 at 7:16:04 PM UTC, wrote:
My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.

Get your multimeter out & find out. Does the programmer's 'CH on' wire
stay live or not?

And how do you do that?

Remove the programmer from the base plate and then there is no permanent
live to test the switched live.

Pick the appropriate circus diagram from :

http://wiki.diyfaq.org.uk/index.php?...s_and_Zonin g

and poke about with your DVM in the wiring centre ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In message , ARW
writes
wrote in message
...
On Tuesday, February 24, 2015 at 7:16:04 PM UTC, wrote:
My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.

Get your multimeter out & find out. Does the programmer's 'CH on'
wire stay live or not?

And how do you do that?

Remove the programmer from the base plate and then there is no
permanent live to test the switched live.



check the other end of the CH on wire to see if it live?

--
Chris French

On Tuesday, February 24, 2015 at 9:43:08 PM UTC, ARW wrote:
wrote in message
...
On Tuesday, February 24, 2015 at 7:16:04 PM UTC, wrote:
My daughter has a fairly old fashioned but pretty standard gas CH
system which is controlled by a Horstmann H37 controller.

A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

Is this likely to be simply a programmer fault/failure or are there
other possible explanations? The programmer is obsolute so if it
is faulty will have to be replaced.

Get your multimeter out & find out. Does the programmer's 'CH on' wire
stay live or not?

And how do you do that?

Remove the programmer from the base plate and then there is no permanent
live to test the switched live.

so probe the wiring centre end of the cable, or attach cable and put programmer back. Its not rocket surgery


NT

On Tue, 24 Feb 2015 15:02:57 -0800 (PST), wrote:

Get your multimeter out & find out. Does the programmer's 'CH on'
wire
stay live or not?

And how do you do that?

Remove the programmer from the base plate and then there is no
permanent live to test the switched live.

so probe the wiring centre end of the cable, or attach cable and put
programmer back. Its not rocket surgery

Or measure between the C and NO heating terminals on the back of
programmer.

--
Cheers
Dave.

On Tue, 24 Feb 2015 19:05:35 +0000, wrote:


A couple of months ago it stopped working completely, it was blowing
the fuse in the wiring box. After a bit of diagnosis with a meter I
discovered that the suppresor capacitor in the control box on the
boiler had failed. I fixed that (with a proper X rated mains
capacitor) and everything worked perfectly again - until now.

Now the controller doesn't turn the boiler off at all, the only way to
stop the boiler is to remove power from it (there is a switch to do
this).

The failed capacitor may have damaged relay contacts in the controller
and they have now decided to weld themselves together. Even if the
controller is obsolete relays are pretty standard and you may well be
able to fix. If not speak to Geoff at CET http://www.cetltd.com/ who
may be able to help if you say you came from here :-)