Potterton Prima F60.

Sometimes the boiler fires up correctly, but the igniter keeps firing every
few seconds as if it doesn't 'think' the gas is lit. Usually does this a
couple of times, and then is happy.

Occasionally, it will turn the gas of, refire (and light correctly) and
then turns the gas of and repeat a few times.

I'm guessing that the thermocouple is on the way out (it is sitting happily
in the flame and getting hot).

However, when our usual gas fitter came and had a look, he noticed that the
flame was lifting, and found that the concentric section of the flue had
corroded away to dust, so the exhaust was being recycled into the inlet
causing a poor burn and reduced pressure, causing the ignition repeating
problem. Flue conversion kit fitted, and sure enough problem solved. For a
few days.

Now the problem is back, and very intermittant, but clearly there is still
a fault. Is it the thermocouple, or sometthing more expensive ;-)

Cheers,

Al.

On 21 Apr 2008 16:40:49 GMT, Al wrote:

Potterton Prima F60.

Sometimes the boiler fires up correctly, but the igniter keeps firing every
few seconds as if it doesn't 'think' the gas is lit. Usually does this a
couple of times, and then is happy.

Occasionally, it will turn the gas of, refire (and light correctly) and
then turns the gas of and repeat a few times.

I'm guessing that the thermocouple is on the way out (it is sitting happily
in the flame and getting hot).

However, when our usual gas fitter came and had a look, he noticed that the
flame was lifting, and found that the concentric section of the flue had
corroded away to dust, so the exhaust was being recycled into the inlet
causing a poor burn and reduced pressure, causing the ignition repeating
problem. Flue conversion kit fitted, and sure enough problem solved. For a
few days.

Now the problem is back, and very intermittant, but clearly there is still
a fault. Is it the thermocouple, or sometthing more expensive ;-)

Cheers,

Al.

Did your gas fitter not know?
--
http://www.orderonlinepickupinstore.co.uk
Ah fetch it yourself if you can't wait for delivery
http://www.freedeliveryuk.co.uk
http://www.holidayunder100.co.uk

Did your gas fitter not know?

He was thrown by the rusty corroded flakes around the flue. And he was
right - It was like a lace curtain when it came out :-(

Problem now is that the fault only occurs at weekends, or betwwen 10pm and
6am ;-) Basically, sods law applies.

I dare say he could replace umpteen PCBs etc, sensors, whatever, but he's
never witnessed the fault and is loath to change/charge without some first
hand evidence.

Basically, I was asking if this is known fault with this boiler (or any
other boiler) before spending money :-)

Al.

In message , Al
writes
Potterton Prima F60.

Sometimes the boiler fires up correctly, but the igniter keeps firing every
few seconds as if it doesn't 'think' the gas is lit. Usually does this a
couple of times, and then is happy.

Occasionally, it will turn the gas of, refire (and light correctly) and
then turns the gas of and repeat a few times.

I'm guessing that the thermocouple is on the way out (it is sitting happily
in the flame and getting hot).

However, when our usual gas fitter came and had a look, he noticed that the
flame was lifting, and found that the concentric section of the flue had
corroded away to dust, so the exhaust was being recycled into the inlet
causing a poor burn and reduced pressure, causing the ignition repeating
problem. Flue conversion kit fitted, and sure enough problem solved. For a
few days.

Now the problem is back, and very intermittant, but clearly there is still
a fault. Is it the thermocouple, or sometthing more expensive ;-)

There is no thermocouple

Lack of flame sensing is down to

1) defective pcb (407677)
2) HT lead broken - not conducting the flame sensing current
3) electrode not in the flame
4) flame still lifting
5) bad earthing
(6) Live and neutral reversed)
--
geoff

On Mon, 21 Apr 2008 19:18:20 +0000, geoff wrote:

In message , Al
writes
Potterton Prima F60.

Sometimes the boiler fires up correctly, but the igniter keeps firing
every few seconds as if it doesn't 'think' the gas is lit. Usually does
this a couple of times, and then is happy.

Occasionally, it will turn the gas of, refire (and light correctly) and
then turns the gas of and repeat a few times.

I'm guessing that the thermocouple is on the way out (it is sitting
happily in the flame and getting hot).

However, when our usual gas fitter came and had a look, he noticed that
the flame was lifting, and found that the concentric section of the flue
had corroded away to dust, so the exhaust was being recycled into the
inlet causing a poor burn and reduced pressure, causing the ignition
repeating problem. Flue conversion kit fitted, and sure enough problem
solved. For a few days.

Now the problem is back, and very intermittant, but clearly there is
still a fault. Is it the thermocouple, or sometthing more expensive ;-)

There is no thermocouple

Lack of flame sensing is down to

1) defective pcb (407677)
2) HT lead broken - not conducting the flame sensing current 3)
electrode not in the flame
4) flame still lifting
5) bad earthing
(6) Live and neutral reversed)

My guess of a descending order would be
4, 3, 2, 1, 5, 6

I'm truly amazed that a replacement flue was available for this model.
Also corrosion of the flue is a fairly rare occurrence and might indicate
a more serious problem with boiler. I'm thinking may be something to do
with the fan or the heat exchanger?



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

On 21 Apr 2008 18:31:02 GMT, Al wrote:

Did your gas fitter not know?

He was thrown by the rusty corroded flakes around the flue. And he was
right - It was like a lace curtain when it came out :-(

Problem now is that the fault only occurs at weekends, or betwwen 10pm and
6am ;-) Basically, sods law applies.

I dare say he could replace umpteen PCBs etc, sensors, whatever, but he's
never witnessed the fault and is loath to change/charge without some first
hand evidence.


Get a camcorder!


Basically, I was asking if this is known fault with this boiler (or any
other boiler) before spending money :-)

Al.
--
http://www.orderonlinepickupinstore.co.uk
Ah fetch it yourself if you can't wait for delivery
http://www.freedeliveryuk.co.uk
http://www.holidayunder100.co.uk