The "no flame" neon indicator is flashing (suggests flame failure or
condensate drain blockage).

The condensate drain is not blocked.

If I reset the boiler, and get it to restart, then running a hot water
tap or turning on the central heating starts up the flame and fan.

If there is demand, the flame

* comes on
* cuts out after 10 seconds
* comes back on after about 25 seconds
* cuts out after 10 seconds
* comes back on after about 25 seconds
* cuts out after 10 seconds

.... and then the boiler goes back into fault mode.

The repair manual suggests that the PCB could be the issue; in fact I
replaced that a few years ago, but I can't remember whether it was the
same fault.

Any immediate ideas?

Daniele

D.M. Procida wrote:
The "no flame" neon indicator is flashing (suggests flame failure or
condensate drain blockage).

The condensate drain is not blocked.

If I reset the boiler, and get it to restart, then running a hot water
tap or turning on the central heating starts up the flame and fan.

If there is demand, the flame

* comes on
* cuts out after 10 seconds
* comes back on after about 25 seconds
* cuts out after 10 seconds
* comes back on after about 25 seconds
* cuts out after 10 seconds

... and then the boiler goes back into fault mode.

The repair manual suggests that the PCB could be the issue; in fact I
replaced that a few years ago, but I can't remember whether it was the
same fault.

Any immediate ideas?

Daniele


Ignition detection fault? Its possibly going through a cycle of ignition
attempts not detecting that the flame has lit.

If it has flame detecting electrodes, sometimes a clean/tweak of the
electrodes will restore flame detection.

Tim

--
Please don't feed the trolls

On 27/10/2019 10:46, Tim+ wrote:
D.M. Procida wrote:
The "no flame" neon indicator is flashing (suggests flame failure or
condensate drain blockage).

The condensate drain is not blocked.

If I reset the boiler, and get it to restart, then running a hot water
tap or turning on the central heating starts up the flame and fan.

If there is demand, the flame

* comes on
* cuts out after 10 seconds
* comes back on after about 25 seconds
* cuts out after 10 seconds
* comes back on after about 25 seconds
* cuts out after 10 seconds

... and then the boiler goes back into fault mode.

The repair manual suggests that the PCB could be the issue; in fact I
replaced that a few years ago, but I can't remember whether it was the
same fault.

Any immediate ideas?

Daniele


Ignition detection fault? Its possibly going through a cycle of ignition
attempts not detecting that the flame has lit.

If it has flame detecting electrodes, sometimes a clean/tweak of the
electrodes will restore flame detection.

Make sure the earth connection in its power supply is good as well -
many will use flame rectification for flame sensing, and that needs an
earthed chassis.


--
Cheers,

John.

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

D.M. Procida wrote:

The "no flame" neon indicator is flashing (suggests flame failure or
condensate drain blockage).

The condensate drain is not blocked.

However, I seem to have fixed it by removing the condensation tank, and
drying it, particularly near where the sensor wire is connected to it. I
think that it was damp, and sufficient current was leaking to trigger
the fault indication.

Daniele