I have the programmer listed above which we used through winter
without any problems. However now that summers arrived and the CH has
been set to OFF, I dont get any hot water. I've tested it a few
times, but the HW setting alone fails to ignite the boiler.

If I turn the Central heating to ON or AUTO, the boiler ignites and
the hot water works fine.

Any ideas?

In an earlier contribution to this discussion, Daniel Fox
wrote:
I have the programmer listed above which we used through winter
without any problems. However now that summers arrived and the CH has
been set to OFF, I dont get any hot water. I've tested it a few
times, but the HW setting alone fails to ignite the boiler.

If I turn the Central heating to ON or AUTO, the boiler ignites and
the hot water works fine.

Any ideas?

Do you have a fully pumped system - with a 3-port mid-position motorised
valve to direct the flow to CH and/or HW as required? If so, your problem is
probably with that.

The first thing to try is to turn the whole heating system off at it's main
switch (not just at the programer) and try again. The internal logic in
3-port valves sometimes gets confused, and this resets them to their 'home'
position, and sometimes cures the problem. If you observe the 3-port valve
as you turn the power off, you will probably hear it moving, using its
spring return.

If your system isn't like this, or if this doesn't fix it, come back with
further details. Did it work *last* summer, or is this the first sumer in
which you have used it?
--
Cheers,
Set Square

Thanks for your comments.

Its the 1st summer in this house so I don't know if it worked last
year or not. I'll try what you suggest but in the meantime can you
help me understand the system?

The 3-port mid-position motorised valve you talk about would be a
small silver coloured 'box' situated close to the hot water tank,
connected to three pipes.

Is is posible to have a 2-way version? If so, could this be the cause
of my problem?






"Set Square" wrote in message ...
In an earlier contribution to this discussion, Daniel Fox
wrote:
I have the programmer listed above which we used through winter
without any problems. However now that summers arrived and the CH has
been set to OFF, I dont get any hot water. I've tested it a few
times, but the HW setting alone fails to ignite the boiler.

If I turn the Central heating to ON or AUTO, the boiler ignites and
the hot water works fine.

Any ideas?

Do you have a fully pumped system - with a 3-port mid-position motorised
valve to direct the flow to CH and/or HW as required? If so, your problem is
probably with that.

The first thing to try is to turn the whole heating system off at it's main
switch (not just at the programer) and try again. The internal logic in
3-port valves sometimes gets confused, and this resets them to their 'home'
position, and sometimes cures the problem. If you observe the 3-port valve
as you turn the power off, you will probably hear it moving, using its
spring return.

If your system isn't like this, or if this doesn't fix it, come back with
further details. Did it work *last* summer, or is this the first sumer in
which you have used it?

In an earlier contribution to this discussion,
Daniel Fox wrote:

Thanks for your comments.

Its the 1st summer in this house so I don't know if it worked last
year or not. I'll try what you suggest but in the meantime can you
help me understand the system?

The 3-port mid-position motorised valve you talk about would be a
small silver coloured 'box' situated close to the hot water tank,
connected to three pipes.

Is is posible to have a 2-way version? If so, could this be the cause
of my problem?


If it has 3 connections - i.e. an inlet and 2 outlets - it is either a
mid-position valve or a diverter valve. A diverter valve switches between HW
and CH, and can't do both together. This is used in W-Plan systems [See
http://content.honeywell.com/uk/homes/systems.htm ] A mid-position valve can
feed either the CH or the HW *or* both at the same time (when in its mid
position). This is used in Y-Plan systems (see above).
2-port valves have onlt 2 connections - an inlet and an outlet - and act
like an on/off switch for water. You would have 2 of these in an S-Plan
system.

Any of these systems should be able to provide HW without CH if they are
installed and functioning correctly.

See if you can work out what you've got from the Honeywell info referenced
above.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

In message , Daniel Fox
writes
I have the programmer listed above which we used through winter
without any problems. However now that summers arrived and the CH has
been set to OFF, I dont get any hot water. I've tested it a few
times, but the HW setting alone fails to ignite the boiler.

If I turn the Central heating to ON or AUTO, the boiler ignites and
the hot water works fine.

Prolly either the diverter valve has failed, or the contacts in the
6300 relay have gone. Can you hear the relay inside the controller
clicking in and out as you switch from on to off, does the display
indicate the change of state?

Of course, it's possible that the track inside the controller has done
an impression of a fuse
--
geoff