My Isar is not igniting, and having followed the fault finding
flowchart there are no error codes either - in fact nothing on the
digital display. There is power and gas to the boiler. It's not working
on DHW or heating

According to the chart, if no error codes are shown or no '0' on the
display (to show that it is on standby) then there is not a problem
with the boiler - but I should contact the installer!

Is there anything that I should suspect to be more like to be causing
this problem?

I don't know if this is significant, but the CH has been off all summer
and two weeks ago I noticed the pressure guage was near 0 so I let
some more water into the CH system. Obviously a bit of a leak
somewhere, but as the heating is not on I thought it would be a job for
another day. Having read the user guide it does mention that the boiler
should not be iignited if the presuure has gone to 0 and been refilled.

But this was two weeks ago and the boiler was working OK since, and the
CH is off anyway. So I don't know how this would affect things.

Cheers

dg

dg wrote:

According to the chart, if no error codes are shown or no '0' on the
display (to show that it is on standby) then there is not a problem
with the boiler - but I should contact the installer!

So what have you got on the display? 0 or is it blank?

Is there anything that I should suspect to be more like to be causing
this problem?

If it is blank, then the first thing to check would be that power is
actually getting to the boiler. The power connector into the back
underside of the back of the control module housing - you could check
there for volts and also make sure it is still connected correctly.

I don't know if this is significant, but the CH has been off all summer
and two weeks ago I noticed the pressure guage was near 0 so I let
some more water into the CH system. Obviously a bit of a leak
somewhere, but as the heating is not on I thought it would be a job for
another day. Having read the user guide it does mention that the boiler
should not be iignited if the presuure has gone to 0 and been refilled.

But this was two weeks ago and the boiler was working OK since, and the
CH is off anyway. So I don't know how this would affect things.

Probably not significant. The pressure in the CH system is relevant even
for HW production though since it is uses the same primary circuit for
hot water heating. (a diversion valve closes to short circuit the flow
and return through the hot water plate heat exchanger rather than
through the rads. This in turn heats the hot water).

--
Cheers,

John.

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

John Rumm wrote:
dg wrote:

According to the chart, if no error codes are shown or no '0' on the
display (to show that it is on standby) then there is not a problem
with the boiler - but I should contact the installer!

So what have you got on the display? 0 or is it blank?

Is there anything that I should suspect to be more like to be causing
this problem?

If it is blank, then the first thing to check would be that power is
actually getting to the boiler. The power connector into the back
underside of the back of the control module housing - you could check
there for volts and also make sure it is still connected correctly.

I don't know if this is significant, but the CH has been off all summer
and two weeks ago I noticed the pressure guage was near 0 so I let
some more water into the CH system. Obviously a bit of a leak
somewhere, but as the heating is not on I thought it would be a job for
another day. Having read the user guide it does mention that the boiler
should not be iignited if the presuure has gone to 0 and been refilled.

But this was two weeks ago and the boiler was working OK since, and the
CH is off anyway. So I don't know how this would affect things.

Probably not significant. The pressure in the CH system is relevant even
for HW production though since it is uses the same primary circuit for
hot water heating. (a diversion valve closes to short circuit the flow
and return through the hot water plate heat exchanger rather than
through the rads. This in turn heats the hot water).

--
Cheers,

John.

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


There is no display at all - just blank.

Power seems to be getting to the boiler as the on/off switch is
illuminated, but I suppose this does not mean that the power is getting
any further.

Thanks

dg

dg wrote:

There is no display at all - just blank.

Power seems to be getting to the boiler as the on/off switch is
illuminated, but I suppose this does not mean that the power is getting
any further.

Yours must be different to mine then, because I don't think my switch is
illuminated at any time.

Any other signs of life from the boiler? It ought to go through an
attempt to temper its small internal store of hot water at power up. If
it fails to do this you would normally expect it to end with a failure
code. Does it sound like it does *anything* at switch on? (click, whirr,
run the pump etc)

When you open a hot water tap what do you hear from the boiler?

What other tests have you done so far? Have you got a mutimeter handy?

--
Cheers,

John.

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

John Rumm wrote:
dg wrote:

There is no display at all - just blank.

Power seems to be getting to the boiler as the on/off switch is
illuminated, but I suppose this does not mean that the power is getting
any further.

Yours must be different to mine then, because I don't think my switch is
illuminated at any time.

Any other signs of life from the boiler? It ought to go through an
attempt to temper its small internal store of hot water at power up. If
it fails to do this you would normally expect it to end with a failure
code. Does it sound like it does *anything* at switch on? (click, whirr,
run the pump etc)

When you open a hot water tap what do you hear from the boiler?

What other tests have you done so far? Have you got a mutimeter handy?

--
Cheers,

John.

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

Sorry for the delay, I've had a fews days away so put this problem on
the backburner so to speak.

I've done no tests yet, but will have a look at what power is getting
around the boiler after the on/off switch.

My switch has a little orange light to indicate that it is on. There
are no noises at all from the boiler, no pumps, no ignition, no clicks
and nothing when the taps are opened or the room thermostat turned up.

The fact that there is no display (which should show the '0') and no
fault code would seem to suggest to me a problem with the electronics
or no power to the circuits after the power switch

cheers

dg