I de-aired the Central Heating system today, a thing I need to do about once a
month. I did so from the towel rail in the bathroom, the highest point in the
system.

Following a suggestion from someone on this NG I lit the escaping air with a
match as the air was flowing out following the loosening of the drain screw.
It lit up like a gas welding torch and caused me to all but jump out of my
underpants.

Is there an expert on this NG who can tell me what this would indicate? And
any cure for the constant need to de-air the system.

The system is 20 years old from new, but with a new Worcester Bosch Greenstar
25i boiler that is one year old.
Peter
--
A Conservative Government is an organised hypocrisy.
Benjamin Disraeli 1804 - 1881

On 18/01/2021 19:29, Peter James wrote:
I de-aired the Central Heating system today, a thing I need to do about once a
month. I did so from the towel rail in the bathroom, the highest point in the
system.

Following a suggestion from someone on this NG I lit the escaping air with a
match as the air was flowing out following the loosening of the drain screw.
It lit up like a gas welding torch and caused me to all but jump out of my
underpants.

Is there an expert on this NG who can tell me what this would indicate? And
any cure for the constant need to de-air the system.

The system is 20 years old from new, but with a new Worcester Bosch Greenstar
25i boiler that is one year old.
Peter

It means you are collecting hydrogen in there. So, you are corroding
steel. That might mean that the inhibitor is depleted.

Do you need to repressurise frequently? That would mean you either have
a leak or that you are expelling water from the relief valve (perhaps
because the expansion vessel has failed, although that is less likely on
a one year old system).

In message , Peter James
writes
I de-aired the Central Heating system today, a thing I need to do about once a
month. I did so from the towel rail in the bathroom, the highest point in the
system.

Following a suggestion from someone on this NG I lit the escaping air with a
match as the air was flowing out following the loosening of the drain screw.
It lit up like a gas welding torch and caused me to all but jump out of my
underpants.

Is there an expert on this NG who can tell me what this would indicate? And
any cure for the constant need to de-air the system.

The system is 20 years old from new, but with a new Worcester Bosch Greenstar
25i boiler that is one year old.
An expert will be along shortly but meanwhile.. Hydrogen is what is left
after internal radiator rusting has removed the O2.

System needs topping up with anti-corrosion fluid.

--
Tim Lamb

Tim Lamb formulated the question :
anti-corrosion fluid.

'Inhibitor'!

If the system is rusting the likely the water will be filled with
debris too. Time for a thorough flush out, or maybe even a power flush,
a refill then the inhibitor.

On 18/01/2021 19:29, Peter James wrote:
I de-aired the Central Heating system today, a thing I need to do about once a
month. I did so from the towel rail in the bathroom, the highest point in the
system.

Following a suggestion from someone on this NG I lit the escaping air with a
match as the air was flowing out following the loosening of the drain screw.
It lit up like a gas welding torch and caused me to all but jump out of my
underpants.

Is there an expert on this NG who can tell me what this would indicate? And
any cure for the constant need to de-air the system.

The system is 20 years old from new, but with a new Worcester Bosch Greenstar
25i boiler that is one year old.
Peter


As others have said, it's hydrogen - which indicates corrosion.

But if you had a new boiler a year ago, didn't the installer do a system
flush and then add inhibitor? If that had been properly, you shouldn't
have this problem after only a year.

Is it a vented primary system, or is it pressurised? If the former, it
could be leaking and introducing fresh oxygen in the top-up water. Or it
could be pumping over and introducing air. If the latter, there could be
a problem with the pressure vessel. In this case, you would be aware of
having to re-pressurise it frequently.
--
Cheers,
Roger

On 18/01/2021 23:08, Roger Mills wrote:
On 18/01/2021 19:29, Peter James wrote:
I de-aired the Central Heating system today, a thing I need to do
about once a
month.Â* I did so from the towel rail in the bathroom, the highest
point in the
system.

Following a suggestion from someone on this NG I lit the escaping air
with a
match as theÂ* air was flowing out following the loosening of the drain
screw.
It lit up like a gas welding torch and caused me to all but jump out
of my
underpants.

Is there an expert on this NG who can tell me what this would
indicate?Â* And
any cure for the constant need to de-air the system.

The system is 20 years old from new, but with a new Worcester Bosch
Greenstar
25i boiler that is one year old.
Peter


As others have said, it's hydrogen - which indicates corrosion.

But if you had a new boiler a year ago, didn't the installer do a system
flush and then add inhibitor? If that had been properly, you shouldn't
have this problem after only a year.

Is it a vented primary system, or is it pressurised? If the former, it
could be leaking and introducing fresh oxygen in the top-up water. Or it
could be pumping over and introducing air. If the latter, there could be
a problem with the pressure vessel. In this case, you would be aware of
having to re-pressurise it frequently.

Pump over would aerate/oxygenate the water and the last gas I would
expect to come out of a vent would be hydrogen.

I would also suggest adding inhibitor pretty smartish, perhaps by adding
a magnetic trap if the system doesn't already have one and filling
through that if the system is unvented.

On 19/01/2021 01:55, Fredxx wrote:
On 18/01/2021 23:08, Roger Mills wrote:
On 18/01/2021 19:29, Peter James wrote:
I de-aired the Central Heating system today, a thing I need to do
about once a
month.Â* I did so from the towel rail in the bathroom, the highest
point in the
system.

Following a suggestion from someone on this NG I lit the escaping air
with a
match as theÂ* air was flowing out following the loosening of the
drain screw.
It lit up like a gas welding torch and caused me to all but jump out
of my
underpants.

Is there an expert on this NG who can tell me what this would
indicate?Â* And
any cure for the constant need to de-air the system.

The system is 20 years old from new, but with a new Worcester Bosch
Greenstar
25i boiler that is one year old.
Peter


As others have said, it's hydrogen - which indicates corrosion.

But if you had a new boiler a year ago, didn't the installer do a
system flush and then add inhibitor? If that had been properly, you
shouldn't have this problem after only a year.

Is it a vented primary system, or is it pressurised? If the former, it
could be leaking and introducing fresh oxygen in the top-up water. Or
it could be pumping over and introducing air. If the latter, there
could be a problem with the pressure vessel. In this case, you would
be aware of having to re-pressurise it frequently.

Pump over would aerate/oxygenate the water and the last gas I would
expect to come out of a vent would be hydrogen.

Yebbut - the oxygen would encourage corrosion which, in turn, would
produce hydrogen.

I would also suggest adding inhibitor pretty smartish, perhaps by adding
a magnetic trap if the system doesn't already have one and filling
through that if the system is unvented.


Agreed.
--
Cheers,
Roger