Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Start by checking that you are getting a call for heat right through to
the boiler. That will prove that the programmer, stats, and valve
microswitches are doing their stuff.


--
Cheers,

John.

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

On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

--
Cheers
Dave.

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?


Pikeys stole your oil :-)

Mike McLeod Wrote in message:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?


Photocell window sooted up?
--
Jimk


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On Sun, 28 Jun 2020 20:24:41 +0100, John Rumm
wrote:

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Start by checking that you are getting a call for heat right through to
the boiler. That will prove that the programmer, stats, and valve
microswitches are doing their stuff.

If by "boiler" you mean the actual burner, I can't get access to its
control box because of the bloody stupid construction of the boiler's
components. They've made it impossible to get the control box cover
off by juxtaposing it with (IIRC) the heat exchanger. If not the HE,
then something equally bulky and obstructive. I believe Worcesters are
notorious for this kind of poor internal layout.

On 28/06/2020 20:46, Mike McLeod wrote:
On Sun, 28 Jun 2020 20:24:41 +0100, John Rumm
wrote:

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Start by checking that you are getting a call for heat right through to
the boiler. That will prove that the programmer, stats, and valve
microswitches are doing their stuff.

If by "boiler" you mean the actual burner, I can't get access to its

No, just the call for heat to the boiler's input terminal as a starter.

i.e. n point diagnosing a problem with the boiler if its actually a
problem with the controls external to it.

Is the pump controlled by the boiler, or is it powered up from the
external controls?

--
Cheers,

John.

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

What indicator lamps are lit? John Rumm has asked you to check if there is a call for heat. If there is then examine further links in the sequence.
Is the overheat stat tripped?
Is there a lockout indicator lit?
If you have the boiler installation and service manual it would (should) help you immensely. If not try downloading a copy from one of the internet sources.

On Sun, 28 Jun 2020 20:50:27 +0100, John Rumm
wrote:


No, just the call for heat to the boiler's input terminal as a starter.

"boiler's input terminal" - sorry, that makes no sense to me.

i.e. n point diagnosing a problem with the boiler if its actually a
problem with the controls external to it.

Very true.


Is the pump controlled by the boiler, or is it powered up from the
external controls?

I think the *pump* is running, but it's so quiet I can only hear it
via holding a pipe to my ear against it.

On Sun, 28 Jun 2020 20:35:28 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

No, the lock-out light hasn't come on and it gets a yearly service
under a contract from a large company.

On 28/06/2020 22:02, Mike McLeod wrote:
On Sun, 28 Jun 2020 20:50:27 +0100, John Rumm
wrote:


No, just the call for heat to the boiler's input terminal as a starter.

"boiler's input terminal" - sorry, that makes no sense to me.

i.e. n point diagnosing a problem with the boiler if its actually a
problem with the controls external to it.

Very true.


Is the pump controlled by the boiler, or is it powered up from the
external controls?

I think the *pump* is running, but it's so quiet I can only hear it
via holding a pipe to my ear against it.

So if you have a conventional wiring plan without pump overrun (i.e. the
pump runs any time there is a call for heat, then that does suggest a
boiler fault. If however the boiler controls the pump, then it suggests
it is at least seeing the call for heat even if not firing. So both
outcomes suggest a boiler problem.

So either a lockout / fault condition preventing it proving and firing,
or something like a valve problem - either not getting an instruction to
open, or not responding.


--
Cheers,

John.

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

On 28/06/2020 21:50, Cynic wrote:
What indicator lamps are lit? John Rumm has asked you to check if there is a call for heat. If there is then examine further links in the sequence.
Is the overheat stat tripped?
Is there a lockout indicator lit?
If you have the boiler installation and service manual it would (should) help you immensely. If not try downloading a copy from one of the internet sources.


Manual he

http://www.worcester-bosch.co.uk/sup...2Jr0PL_jzfixWI


--
Cheers,

John.

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

Mike McLeod Wrote in message:
On Sun, 28 Jun 2020 20:35:28 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

No, the lock-out light hasn't come on and it gets a yearly service
under a contract from a large company.


Time to ring the large company then?
--
Jimk


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On Sun, 28 Jun 2020 22:59:27 +0100, John Rumm
wrote:

On 28/06/2020 21:50, Cynic wrote:
What indicator lamps are lit?

Just the "power" one on the front, as usual.


John Rumm has asked you to check if there is a call for heat. If there is then examine further links in the sequence.

There's a flow chart in the documentation John kindly linked to.

Is the overheat stat tripped?

Can't find it.

Is there a lockout indicator lit?

Nope

If you have the boiler installation and service manual it would (should) help you immensely.

It *should* shouldn't it? Unfortunately Worcester/Bosch's circuit
diagram is unreadable for me at any rate (and I'm no stranger to
circuit diagrams, believe me).

Manual he

http://www.worcester-bosch.co.uk/sup...2Jr0PL_jzfixWI

The main problem is that they've basically prioritised compactness
over everything else. So it appears they've taken all the components
of the boiler and used some CAD program to determine the best way to
fit all these objects into the smallest external dimensions possible
with no thought whatsoever into subsequent servicing access.
One of the *key* tests in the manual is to check for 40 ohms across
the fan motor, but like I said, it's completely inaccessible without
taking much of the whole damn thing to bits. Useless! From my
researches it's one of the boilers the service engineers most hate
working on for this very reason.

On Sun, 28 Jun 2020 23:14:25 +0100 (GMT+01:00), Jimk
wrote:


Time to ring the large company then?

Yep, I just wanted to check I hadn't overlooked anything before
calling them.

On 28/06/2020 23:41, Mike McLeod wrote:
On Sun, 28 Jun 2020 22:59:27 +0100, John Rumm
wrote:

On 28/06/2020 21:50, Cynic wrote:
What indicator lamps are lit?

Just the "power" one on the front, as usual.


John Rumm has asked you to check if there is a call for heat. If there is then examine further links in the sequence.

There's a flow chart in the documentation John kindly linked to.

Is the overheat stat tripped?

Can't find it.

Is there a lockout indicator lit?

Nope

If you have the boiler installation and service manual it would (should) help you immensely.

It *should* shouldn't it? Unfortunately Worcester/Bosch's circuit
diagram is unreadable for me at any rate (and I'm no stranger to
circuit diagrams, believe me).

Manual he

http://www.worcester-bosch.co.uk/sup...2Jr0PL_jzfixWI

The main problem is that they've basically prioritised compactness
over everything else. So it appears they've taken all the components
of the boiler and used some CAD program to determine the best way to
fit all these objects into the smallest external dimensions possible
with no thought whatsoever into subsequent servicing access.
One of the *key* tests in the manual is to check for 40 ohms across
the fan motor, but like I said, it's completely inaccessible without
taking much of the whole damn thing to bits. Useless! From my
researches it's one of the boilers the service engineers most hate
working on for this very reason.

Does the boiler have a programmer fitted to it, and if so has it been
inadvertently changed?

--
Michael Chare

On 28/06/2020 23:49, Mike McLeod wrote:
On Sun, 28 Jun 2020 23:14:25 +0100 (GMT+01:00), Jimk
wrote:


Time to ring the large company then?

Yep, I just wanted to check I hadn't overlooked anything before
calling them.


It looks like you can unplug the burner power cable from the boiler
chassis. If you do this you could then check whether you have power on
pins 1 and 2 when the burner is supposed to be running.

--
Michael Chare

On Mon, 29 Jun 2020 00:08:52 +0100, Michael Chare
wrote:

Does the boiler have a programmer fitted to it, and if so has it been
inadvertently changed?

Nope. Just simple on-off switches. I keep irregular hours.

On Mon, 29 Jun 2020 00:23:16 +0100, Michael Chare
wrote:

On 28/06/2020 23:49, Mike McLeod wrote:
On Sun, 28 Jun 2020 23:14:25 +0100 (GMT+01:00), Jimk
wrote:


Time to ring the large company then?

Yep, I just wanted to check I hadn't overlooked anything before
calling them.


It looks like you can unplug the burner power cable from the boiler
chassis. If you do this you could then check whether you have power on
pins 1 and 2 when the burner is supposed to be running.

Not sure what you mean by "boiler chassis" - one of my major beefs
with this design is that it has no frame at all to give it rigidity.
It is one ****ty design.
I'll check out your suggestion, though, if you meant "controller
board" instead of boiler chassis. I recall there's a plug/socket on
there for it. Not sure why I didn't think of that myself, but I
didn't......

Mike McLeod wrote:
On Sun, 28 Jun 2020 22:59:27 +0100, John Rumm
wrote:

On 28/06/2020 21:50, Cynic wrote:
What indicator lamps are lit?

Just the "power" one on the front, as usual.


John Rumm has asked you to check if there is a call for heat. If there
is then examine further links in the sequence.

There's a flow chart in the documentation John kindly linked to.

Is the overheat stat tripped?

Can't find it.

Number 6 in the drawing in the manual.

Tim
--
Please don't feed the trolls

At least it had the sense to fail in the summer not on the coldest day of
the year I suppose.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Jimk" wrote in message
o.uk...
Mike McLeod Wrote in message:
On Sun, 28 Jun 2020 20:35:28 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

No, the lock-out light hasn't come on and it gets a yearly service
under a contract from a large company.


Time to ring the large company then?
--
Jimk


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?


Oil? Feed blockage?

On 29/06/2020 01:30, Mike McLeod wrote:
On Mon, 29 Jun 2020 00:23:16 +0100, Michael Chare
wrote:

On 28/06/2020 23:49, Mike McLeod wrote:
On Sun, 28 Jun 2020 23:14:25 +0100 (GMT+01:00), Jimk
wrote:


Time to ring the large company then?

Yep, I just wanted to check I hadn't overlooked anything before
calling them.


It looks like you can unplug the burner power cable from the boiler
chassis. If you do this you could then check whether you have power on
pins 1 and 2 when the burner is supposed to be running.

Not sure what you mean by "boiler chassis" - one of my major beefs
with this design is that it has no frame at all to give it rigidity.
It is one ****ty design.
I'll check out your suggestion, though, if you meant "controller
board" instead of boiler chassis. I recall there's a plug/socket on
there for it. Not sure why I didn't think of that myself, but I
didn't......


The power supply cable to the burner can be unplugged. Not all oil
boilers let you do this. It is shown in the manual and can be done on an
earlier version of the boiler which I happen to have.


--
Michael Chare

On Sun, 28 Jun 2020 22:54:20 +0100, John Rumm wrote:

So either a lockout / fault condition preventing it proving and firing,
or something like a valve problem - either not getting an instruction to
open, or not responding.

Or the boiler is controlled via a microswitch on a valve and the
microswitch has failed or the valve is responding but is gunked up
and not opening enough to operate the switch.

--
Cheers
Dave.

On 28/06/2020 20:35, Dave Liquorice wrote:
On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Cleaning the photosensor is always the very first thing to try -
especially after high winds from unusual directions.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

+1

Does the ignition spark actually occur but no flame?

Does the blower run?

Does it smell of kerosene after failing to light?

Weirdest one mine ever had was that it would lockout and not light the
very first time every morning. Turned out to be a failing fuel solenoid
allowing a tiny leak that made a bad sooty flame in the first ignition
that caused immediate lockout. Reset and retry and it was fine all day.

Until the next morning when it failed exactly the same way...

--
Regards,
Martin Brown

On 29/06/2020 10:46, Dave Liquorice wrote:
On Sun, 28 Jun 2020 22:54:20 +0100, John Rumm wrote:

So either a lockout / fault condition preventing it proving and firing,
or something like a valve problem - either not getting an instruction to
open, or not responding.

Or the boiler is controlled via a microswitch on a valve and the
microswitch has failed or the valve is responding but is gunked up
and not opening enough to operate the switch.

If its a conventional wiring with the microswitch firing both the pump
and boiler, then it must be ok if the pump is running. Likewise if the
boiler controls the pump, and its running, then the call for heat must
be getting as far as the boiler.


--
Cheers,

John.

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

On 29 Jun 2020 07:46:52 GMT, Tim+ wrote:

Mike McLeod wrote:
On Sun, 28 Jun 2020 22:59:27 +0100, John Rumm
wrote:

On 28/06/2020 21:50, Cynic wrote:
What indicator lamps are lit?

Just the "power" one on the front, as usual.


John Rumm has asked you to check if there is a call for heat. If there
is then examine further links in the sequence.

There's a flow chart in the documentation John kindly linked to.

Is the overheat stat tripped?

Can't find it.

Number 6 in the drawing in the manual.

Tim

Well, yes, it *had* tripped. I couldn't find it!
I had to call out the engineer in the end. I don't *fully* understand
what happened, but the gist of it was the expansion tank had failed,
the pressure in the system had fallen too far, some overheating had
occurred somewhere and the overheat stat tripped out. If it had just
been the trip I'd have been really ****ed off with myself, but the
fact that the tank had to be replaced anyway made it worthwhile
calling out the engineer, so no regrets over the expense. :-)

On 28/06/2020 22:04, Mike McLeod wrote:
On Sun, 28 Jun 2020 20:35:28 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

No, the lock-out light hasn't come on and it gets a yearly service
under a contract from a large company.


Does central heating oil suffer from the same issue as
red 'bio' diesel ?. The latter apparently grows bugs that
clog up the tractor/combine harvester fuel filters
annoyingly often according to someone with farming connections
who posts here.

Andrew Wrote in message:
On 28/06/2020 22:04, Mike McLeod wrote:
On Sun, 28 Jun 2020 20:35:28 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

No, the lock-out light hasn't come on and it gets a yearly service
under a contract from a large company.


Does central heating oil suffer from the same issue as
red 'bio' diesel ?. The latter apparently grows bugs that
clog up the tractor/combine harvester fuel filters
annoyingly often according to someone with farming connections
who posts here.


Not IME of over 20 years...
--
Jimk


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

does the air pump spin up and the igniter crackle?


--
Renewable energy: Expensive solutions that don't work to a problem that
doesn't exist instituted by self legalising protection rackets that
don't protect, masquerading as public servants who don't serve the public.

On 28/06/2020 20:35, Dave Liquorice wrote:
On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

classic lockout for me is when a gale blows from one direction. the
balanced flue is short and it blows the flame out


--
Renewable energy: Expensive solutions that don't work to a problem that
doesn't exist instituted by self legalising protection rackets that
don't protect, masquerading as public servants who don't serve the public.

On 28/06/2020 22:04, Mike McLeod wrote:
On Sun, 28 Jun 2020 20:35:28 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 28 Jun 2020 19:46:57 +0100, Mike McLeod wrote:

Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

Locked out? Might be an indicator/button on the burner that is now
on, when heat is being called for, that normally isn't on. Try
pressing it, should start its ignigtion sequence but if it's still
not happy may go back into lock out.

Oil boilers are pretty reliable but do occasionally suffer a lockout
for no good reason. If it does go back into lock out, you haven't run
out of oil have you? When was it last serviced?

No, the lock-out light hasn't come on and it gets a yearly service
under a contract from a large company.

if it tries and fails might be a flame sensor


--
Renewable energy: Expensive solutions that don't work to a problem that
doesn't exist instituted by self legalising protection rackets that
don't protect, masquerading as public servants who don't serve the public.

On 28/06/2020 22:02, Mike McLeod wrote:
On Sun, 28 Jun 2020 20:50:27 +0100, John Rumm
wrote:


No, just the call for heat to the boiler's input terminal as a starter.

"boiler's input terminal" - sorry, that makes no sense to me.

i.e. n point diagnosing a problem with the boiler if its actually a
problem with the controls external to it.

Very true.


Is the pump controlled by the boiler, or is it powered up from the
external controls?

I think the *pump* is running, but it's so quiet I can only hear it
via holding a pipe to my ear against it.

there is an air pump as well. That you can hear


--
The lifetime of any political organisation is about three years before
its been subverted by the people it tried to warn you about.

Anon.

Glad to hear you're fixed. However it's worth mentioning to all the blocked fuel supply proponents, an oil boiler sequence control expects to start the ignition cycle with a dark combustion chamber then see a flame within a short time. If neither of these conditions are satisfied the burner locks out and an indicator lamp(s) light up.
It might also be worth adding that most of the oil combis I've ever worked on have the diverter valve and pump(s) in the package so "plan" systems are generally unnecessary. However I do recall fitting one to a large farmhouse so upstairs and downstairs could be programmed for separate times.
The cost of a manufacturers expansion vessel can be quite daunting hence if possible I usually fitted a robokit somewhere convenient and tapped it into the pressurised system. Saved a lot of dismantling and allowed use of a larger expansion capacity.

On Tue, 30 Jun 2020 08:48:36 +0100, The Natural Philosopher
wrote:

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

does the air pump spin up and the igniter crackle?

Thanks for your interest, but it's been fixed now (expansion tank
membrane perforated).

On 30/06/2020 18:25, Mike McLeod wrote:
On Tue, 30 Jun 2020 08:48:36 +0100, The Natural Philosopher
wrote:

On 28/06/2020 19:46, Mike McLeod wrote:
Just stopped working! No hot water or heating. Just won't fire-up for
some reason.

Worcester Greenstar Heatslave 18/25 oil-fired.

Got power to the controller board; no fuses blown. Any suggestions?

does the air pump spin up and the igniter crackle?



Thanks for your interest, but it's been fixed now (expansion tank
membrane perforated).


I wonder why that happens. I have an earlier non condensing version of
that boiler, and the expansion tank was changed for the previous owner
of the house.

--
Michael Chare

On Tue, 30 Jun 2020 18:54:21 +0100, Michael Chare
wrote:

I wonder why that happens. I have an earlier non condensing version of
that boiler, and the expansion tank was changed for the previous owner
of the house.

Well that membrane is continually "in flux" as it were and like
anything else that moves, that causes wear.