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