Hello All

Ive just discovered that my Potterton boiler wont fire up when the
thermostat (CM67) asks for heat. I have cranked the thermostat up to 30
degrees and still no joy. Hot water is fine and works as expected. I
have recently removed a load of radiators upstair but wouldn't of
thought that this would have anything to do with it and Ive also
plumbed in a dual energy towel rad T'd off some existing pipework but
again cant see that this should effect my boiler firing up. Any ideas?

TIA

Cheers

Richard

Could this be a valve problem? just about to go look............

In an earlier contribution to this discussion,
wrote:

Could this be a valve problem? just about to go look............

Have you got a Y-Plan system - with a 3-port mid-position valve which
directs the water to one or other or both circuits?

If so, when there is only a CH demand, it's a microswitch in the valve's
actuator which switches the boiler and pump on. If the valve isn't motoring
to the CH position, or if the micro-switch is duff, the boiler won't come
on.

Similarly, if you have an S-Plan system with separate motorised valves for
each circuit, you still need the valve to open before a set of contacts
turns the boiler on.

Check the valve(s), and check whether the switched live feed to the boiler
is *actually* live.

For Y-Plan or S-Plan wiring diagrams, see
http://content.honeywell.com/uk/homes/systems.htm and scroll down to the
appropriate plan.
--
Cheers,
Set Square
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In message .com,
writes
Hello All

Ive just discovered that my Potterton boiler wont fire up when the
thermostat (CM67) asks for heat. I have cranked the thermostat up to 30
degrees and still no joy. Hot water is fine and works as expected. I
have recently removed a load of radiators upstair but wouldn't of
thought that this would have anything to do with it and Ive also
plumbed in a dual energy towel rad T'd off some existing pipework but
again cant see that this should effect my boiler firing up. Any ideas?

You've been here long enough to realise that there are Potterton boilers
and Potterton boilers

C'mon, give us a clue

--
geoff

has brought this to us :
Could this be a valve problem? just about to go look............

The valve actuator sticking most likely.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org

Cheers SS. Sorry not enough info really on my original post, was in a
rush to get out the door! It is a Y plan with a 3 port.

Well I had a look at the valve, nice shiny thing it is and found a
lever at the side which says auto and manual. I pushed the level to
manual and the boiler fired up. There was some resistance when moving
the lever which I'm assuming was the balls or whatever they are moving
and allowing the water to flow?

I then moved the lever back to auto and tried again, still no joy and
the boiler doesn't fire.

I'm assuming from your post that the microswitch is fecked, but what
does the auto and manual settings do? what will keeping it on manual
do, does that provide water for both the CH system and the HW, so
essentially when I have the CH on the HW will be on too basically both
valves open and not allowing control via the motors?

Cheers

Richard

Its a Potterton kingfisher, Y plan see above, sorry in a rush to get
out the door!

Cheers

Richard

what motorised valve do you have?

Normaly the white wire is the CH side of the valve and is connected to
the CH side of the programer. If the programmer is calling, i.e. on for
CH and the room stat is calling , then the white wire should be at
240volts. You should see the lever on the valve, if working ok, move to
the H side (Port B). If not then could be the valve, programmer or room
stat at fault.

DHW side is the orange wire and you will get same conditions as above
except on the orange wire and valve moves to W side (Port A).

Check with programmer on for DHW if valve moves DHW is working ok.

Check with programmer on for CH if valve moves CH side is ok.

Both DHW and CH on then valve moves to Mid position.

Check with your hand either side of the valve Port A and B to see if
they are getting hot. If DHW is on then B will be hot. If CH is on then
A will get hot.

Note in MID Position they could be equally hot.

Note, you can get a mechanical fault or electrical fault with these
vales.

Regards

In an earlier contribution to this discussion,
wrote:

Cheers SS. Sorry not enough info really on my original post, was in a
rush to get out the door! It is a Y plan with a 3 port.

Well I had a look at the valve, nice shiny thing it is and found a
lever at the side which says auto and manual. I pushed the level to
manual and the boiler fired up. There was some resistance when moving
the lever which I'm assuming was the balls or whatever they are moving
and allowing the water to flow?

I then moved the lever back to auto and tried again, still no joy and
the boiler doesn't fire.

I'm assuming from your post that the microswitch is fecked, but what
does the auto and manual settings do? what will keeping it on manual
do, does that provide water for both the CH system and the HW, so
essentially when I have the CH on the HW will be on too basically both
valves open and not allowing control via the motors?

Cheers

Richard

More likely that the motor isn't working. Moving the lever to the 'manual'
position moves the valve to the mid-way position where you get both CH and
HW at the same time. If the motor is working it will be able to move the
valve all the way to the CH-only position - which is what you need.

Take out the 2 screws which fix the actuator to the valve and lift it off.
make sure that the valve spindle turns freely. If it does, the actuator is
shot and needs to be repaired or replaced. You *can* buy replacement synchro
motors - but it's far easier to replace the whole thing.
--
Cheers,
Set Square
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It happens that Set Square formulated :
Take out the 2 screws which fix the actuator to the valve and lift it off.
make sure that the valve spindle turns freely. If it does, the actuator is
shot and needs to be repaired or replaced. You *can* buy replacement synchro
motors - but it's far easier to replace the whole thing.

I keep a ready repaired actuator alongside the working one, for a quick
swap over. They do fail every few years.

Buy a new one, then work out what has failed on the old one and repair
it as a standby. Motors can be had for around £15, microswitches for
about £1.50 and complete new actuators £30 to £40.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org

Yup motor it was, replaced and all OK

Cheers all

Richard

Where did you get your motor from ? I may be needing one for a danfoss
valve soon, and I'd rather just replace the motor, and not deal with the
wet stuff (I'm an sparky, and don't mix with water)

wrote:
Yup motor it was, replaced and all OK

Cheers all

Richard

In an earlier contribution to this discussion,
Ian Cornish" "icornish at talk21 dot com "icornish at talk21 dot com"
wrote:

Where did you get your motor from ? I may be needing one for a danfoss
valve soon, and I'd rather just replace the motor, and not deal with
the wet stuff (I'm an sparky, and don't mix with water)

Screwfix do one for eight quid which fits a number of actuators - but
unfortunately not Danfoss! [It looks the same in the picture, but apparently
the motor used by Danfoss is a bit bigger].

You can replace the whole actuator on a danfoss valve, of course, without
having to 'mix' with water!
--
Cheers,
Set Square
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