Hi,
In a fit of winter diligence I bled an upstairs radiator which produced a
reasonable hiss. I then found a vertical pipe with a brass ferrule-like
end with a small screw end piece in a vertical line from my 3 position
valve. I loosened it and it hissed. Ah more air found I thought and let
it hiss for a few mins.
**this was with the heating on**

No heating this morning + no woofs from the boiler. On googling I suspect
the hiss from the brass ferrule thing was air going in rather than out.
I'm holding my hands up, in retrospect it doesn't look to have been a
bright thing to do.

Current situation with controller asking for heating+hot water:

1) Boiler (Potterton Netaheat Profile 50e) seems dead, on getting home I
turned the boiler knob up and it fired for 2-3 mins and then stopped
without much fuss i.e. no banging. Presumably it reached some kind of
thermal cut-out as it won't do this any more.

2) pump whirrs and is pretty hot to the touch
3) All pipes around are cold
- this doesn't change if I change mid pos valve to man.


Any help much appreciated.

Jon

No heating this morning + no woofs from the boiler. On googling I
suspect
the hiss from the brass ferrule thing was air going in rather than out.

You need to refill it. Turn it off first! If the pump is running and it is a
vented system, or a sealed system at low pressure, then it may well suck
air.

Now find out if it is a header tank vented system or a pressurised system
with pressure gauge. If the later, connect up the filling hose and turn on
the tap until it reaches 1 bar.

Now go around the house bleeding the rads and any other bleed valves. If you
have the sealed system, you'll need to occassionally return to the tap to
bump the pressure back up. Ensure that you get water expelled at each bleed
point (unless it is an automatic bleed valve which turns itself off).

Finally, turn the system back on.

Christian.

"Jon Telfer" wrote in message
...
Hi,
In a fit of winter diligence I bled an upstairs radiator which produced a
reasonable hiss. I then found a vertical pipe with a brass ferrule-like
end with a small screw end piece in a vertical line from my 3 position
valve. I loosened it and it hissed. Ah more air found I thought and let
it hiss for a few mins.
**this was with the heating on**

No heating this morning + no woofs from the boiler. On googling I
suspect
the hiss from the brass ferrule thing was air going in rather than out.
I'm holding my hands up, in retrospect it doesn't look to have been a
bright thing to do.

Current situation with controller asking for heating+hot water:

1) Boiler (Potterton Netaheat Profile 50e) seems dead, on getting home I
turned the boiler knob up and it fired for 2-3 mins and then stopped
without much fuss i.e. no banging. Presumably it reached some kind of
thermal cut-out as it won't do this any more.

2) pump whirrs and is pretty hot to the touch
3) All pipes around are cold
- this doesn't change if I change mid pos valve to man.


Any help much appreciated.

Jon

There is a thermal cut out on the boiler which may need resetting.
http://www.geocities.com/trenthamlod.../potterton.pdf

Bleed each radiator of air and allow them to spew water for a while which
should pull the airlock out.

Christian McArdle wrote:

No heating this morning + no woofs from the boiler. On googling I
suspect
the hiss from the brass ferrule thing was air going in rather than out.

You need to refill it. Turn it off first! If the pump is running and it is
a vented system, or a sealed system at low pressure, then it may well suck
air.

Now find out if it is a header tank vented system or a pressurised system
with pressure gauge. If the later, connect up the filling hose and turn on
the tap until it reaches 1 bar.

Now go around the house bleeding the rads and any other bleed valves. If
you have the sealed system, you'll need to occassionally return to the tap
to bump the pressure back up. Ensure that you get water expelled at each
bleed point (unless it is an automatic bleed valve which turns itself
off).

Finally, turn the system back on.

Christian.
OK thanks, I've got a small header tank in the loft. This is around half
full.
The upstairs radiator I bled initially gives no air. A nearby one had
some air in but I'm now at a intermediate stage where the valve is open but
I get neither air nor water through. Thoughts?

Thanks,
Jon

On Mon, 19 Dec 2005 18:16:40 +0000, Jon Telfer wrote:

Ah more air found I thought and let
it hiss for a few mins.
**this was with the heating on**

Reminds me of my first encounter with bleeding a radiator ...

1970s. Age 16, parents out, heating on, radiator in my bedroom is cold
at the top. Dad bled it last year and cured the problem, can't be that
hard. I open the vent, hear a quiet hissing noise, noise gets louder
as vent is opened. I decide to open it fully.

At this point, the water level reaches the vent and fires the bleed
nipple across the room. Scalding, black, smelly water gushes out onto
new carpet. I put my thumb over vent, it starts to burn, so I swap
thumbs, it starts to burn ...

Over an hour later, my parents finally return and find bleed nipple.

It's amazing that I ever did any DIY again.

--
Nigel M

"Nigel Molesworth" wrote in message
...
On Mon, 19 Dec 2005 18:16:40 +0000, Jon Telfer wrote:

Ah more air found I thought and let
it hiss for a few mins.
**this was with the heating on**

Reminds me of my first encounter with bleeding a radiator ...

1970s. Age 16, parents out, heating on, radiator in my bedroom is cold
at the top. Dad bled it last year and cured the problem, can't be that
hard. I open the vent, hear a quiet hissing noise, noise gets louder
as vent is opened. I decide to open it fully.

At this point, the water level reaches the vent and fires the bleed
nipple across the room. Scalding, black, smelly water gushes out onto
new carpet. I put my thumb over vent, it starts to burn, so I swap
thumbs, it starts to burn ...

Over an hour later, my parents finally return and find bleed nipple.

It's amazing that I ever did any DIY again.

--
Nigel M

Me too except I was 40 years old :-)

Jon Telfer wrote:

Christian McArdle wrote:

No heating this morning + no woofs from the boiler. On googling I
suspect
the hiss from the brass ferrule thing was air going in rather than out.

You need to refill it. Turn it off first! If the pump is running and it
is a vented system, or a sealed system at low pressure, then it may well
suck air.

Now find out if it is a header tank vented system or a pressurised system
with pressure gauge. If the later, connect up the filling hose and turn
on the tap until it reaches 1 bar.

Now go around the house bleeding the rads and any other bleed valves. If
you have the sealed system, you'll need to occassionally return to the
tap to bump the pressure back up. Ensure that you get water expelled at
each bleed point (unless it is an automatic bleed valve which turns
itself off).

Finally, turn the system back on.

Christian.
OK thanks, I've got a small header tank in the loft. This is around half
full.
The upstairs radiator I bled initially gives no air. A nearby one had
some air in but I'm now at a intermediate stage where the valve is open
but
I get neither air nor water through. Thoughts?

Thanks,
Jon
I think there must be a blockage somewhere. The radiators don't seem to
produce any air or water. I drained about half a washing up bowl from the
outlet at the bottom of the house and there was no movement from the loft
header tank at all.
The drained fluid was clear with no real hint of corrosion, but where did
it come from if there was no replenishment from the loft?

Thanks,

Jon

I think there must be a blockage somewhere. The radiators don't seem to
produce any air or water. I drained about half a washing up bowl from the
outlet at the bottom of the house and there was no movement from the loft
header tank at all.

This is one of the advantages of a sealed system. Filling is easier.

To get rid of airlocks, it might be an idea to close off all the valves and
back feed the drainage point from the garden hose. That way the water blasts
in under pressure. Have someone standing by in the loft to shout when the
header tank is about to overflow.

Christian.