When I've previously drained and refilled our heating system, I
normally seem to get some air circulating in the system. You can hear
when this gets to the boiler (gurgling sounds) and shortly afterwards
the boiler cuts out. A few minutes later it resets itself and off it
goes again. Normally within a few hours the air finds its way into a
radiator, I bleed the rad and then all is well.

However, the last time I drained the system was a few weeks ago and
the boiler is still cutting out. I've tried:
-checking all rads are bled
-running with pump on full speed
-the above with all rads bar one closed off (CH & DHW active)
-bleeding at the boiler end (no air came out)
-bleeding at the upright pipe next to the hot water tank in the airing
cupboard (small amount of air)

When I ran with all bar one rads closed, this seemed to give some
short term improvements (no cut outs for the rest of that day that I
was aware of) but it returned to its usual tricks the day after.

I'm loathed to drain and refill as I added fresh inhibitor the last
time I filled the system. Any other thoughts or suggestions?

Ta,
Neil

On Fri, 21 Dec 2007 00:32:51 -0800, Neil wrote:

When I've previously drained and refilled our heating system, I normally
seem to get some air circulating in the system. You can hear when this
gets to the boiler (gurgling sounds) and shortly afterwards the boiler
cuts out. A few minutes later it resets itself and off it goes again.
Normally within a few hours the air finds its way into a radiator, I
bleed the rad and then all is well.

However, the last time I drained the system was a few weeks ago and the
boiler is still cutting out. I've tried: -checking all rads are bled
-running with pump on full speed
-the above with all rads bar one closed off (CH & DHW active) -bleeding
at the boiler end (no air came out) -bleeding at the upright pipe next
to the hot water tank in the airing cupboard (small amount of air)

When I ran with all bar one rads closed, this seemed to give some short
term improvements (no cut outs for the rest of that day that I was aware
of) but it returned to its usual tricks the day after.

I'm loathed to drain and refill as I added fresh inhibitor the last time
I filled the system. Any other thoughts or suggestions?

Ta,
Neil

Is it a closed or open system?


--
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 Dec, 08:50, Ed Sirett wrote:
On Fri, 21 Dec 2007 00:32:51 -0800, Neil wrote:
When I've previously drained and refilled our heating system, I normally
seem to get some air circulating in the system. *You can hear when this
gets to the boiler (gurgling sounds) and shortly afterwards the boiler
cuts out. *A few minutes later it resets itself and off it goes again.
Normally within a few hours the air finds its way into a radiator, I
bleed the rad and then all is well.

However, the last time I drained the system was a few weeks ago and the
boiler is still cutting out. *I've tried: -checking all rads are bled
-running with pump on full speed
-the above with all rads bar one closed off (CH & DHW active) -bleeding
at the boiler end (no air came out) -bleeding at the upright pipe next
to the hot water tank in the airing cupboard (small amount of air)

When I ran with all bar one rads closed, this seemed to give some short
term improvements (no cut outs for the rest of that day that I was aware
of) but it returned to its usual tricks the day after.

I'm loathed to drain and refill as I added fresh inhibitor the last time
I filled the system. *Any other thoughts or suggestions?

Ta,
Neil

Is it a closed or open system?

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

- Show quoted text -

Open.

On Fri, 21 Dec 2007 02:49:10 -0800, Neil wrote:

May be you have a blockage where the feed pipe joins the circuit.


--
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

Neil wrote:
When I've previously drained and refilled our heating system, I
normally seem to get some air circulating in the system. You can hear
when this gets to the boiler (gurgling sounds) and shortly afterwards
the boiler cuts out. A few minutes later it resets itself and off it
goes again. Normally within a few hours the air finds its way into a
radiator, I bleed the rad and then all is well.

However, the last time I drained the system was a few weeks ago and
the boiler is still cutting out. I've tried:
-checking all rads are bled
-running with pump on full speed
-the above with all rads bar one closed off (CH & DHW active)
-bleeding at the boiler end (no air came out)
-bleeding at the upright pipe next to the hot water tank in the airing
cupboard (small amount of air)

When I ran with all bar one rads closed, this seemed to give some
short term improvements (no cut outs for the rest of that day that I
was aware of) but it returned to its usual tricks the day after.

I'm loathed to drain and refill as I added fresh inhibitor the last
time I filled the system. Any other thoughts or suggestions?

Ta,
Neil


What do you mean 'cutting out'?

In my case that usually means a completely unrelated fault.

Blowback into the balanced flue blowing the flame out usually, or a
sooted up sensor.

My boiler happily runs with quite a lot of air in the rad system.

However, to clear air locks I did find full pump speed. and one section
of pipe at a time would blast the air to a radiator where it could be bled.

On 21 Dec, 15:48, The Natural Philosopher wrote:
Neil wrote:
When I've previously drained and refilled our heating system, I
normally seem to get some air circulating in the system. *You can hear
when this gets to the boiler (gurgling sounds) and shortly afterwards
the boiler cuts out. *A few minutes later it resets itself and off it
goes again. *Normally within a few hours the air finds its way into a
radiator, I bleed the rad and then all is well.

However, the last time I drained the system was a few weeks ago and
the boiler is still cutting out. *I've tried:
-checking all rads are bled
-running with pump on full speed
-the above with all rads bar one closed off (CH & DHW active)
-bleeding at the boiler end (no air came out)
-bleeding at the upright pipe next to the hot water tank in the airing
cupboard (small amount of air)

When I ran with all bar one rads closed, this seemed to give some
short term improvements (no cut outs for the rest of that day that I
was aware of) but it returned to its usual tricks the day after.

I'm loathed to drain and refill as I added fresh inhibitor the last
time I filled the system. *Any other thoughts or suggestions?

Ta,
Neil

What do you mean 'cutting out'?

In my case that usually means a completely unrelated fault.

Blowback into the balanced flue blowing the flame out usually, or a
sooted up sensor.

My boiler happily runs with quite a lot of air in the rad system.

However, to clear air locks I did find full pump speed. and one section
of pipe at a time would blast the air to a radiator where it could be bled..- Hide quoted text -

- Show quoted text -

I think it's fairly normal for boilers to cut out when air passes
through them. It flashes the light as an error code - it's some kind
of protection cut out that auto resets itself after 3 mins or so, by
which time the air has moved on and the boiler gets going again. It's
definitely related to air as if you are near the boiler, you hear the
gurgling noise start, and seconds later the light starts flashing and
the boiler shuts down. I'll maybe try pump on full and small bits of
the heating system turned on at a time and see if that has an
effect... until someone comes up with another suggestion!

Thanks, Neil