A while ago my heating system was changed from an open system with a header
tank to a sealed, pressurised system.

Last week a radiator in the bathroom sprung a leak so I decided to replace
it. Well, long story short, I called in a Plumber (lack of tools, lack of
confidence and lack of strength, in no particular order - me, I mean, not
the Plumber!) who recommended changing the valves along with the rad. This
needed the system to be drained, so he found the stop cock and did so.

It didn't seem to take very long to drain down and despite the drain point
being at the lowest elevation none of the downstairs radiators drained out.
On completion of the job, he opened the cocks on the filling loop,
re-pressurised the system and turned the boiler on again. To my surprise,
none of the radiators either upstairs or down needed bleeding - apart from
the new one - either then or now.

I understood how the old gravity system worked, but I am struggling a bit
with the sealed, pressurised system that I have now.

Firstly, why did so little water run out when he "drained the system"? And
if the system is pressurised, why doesn't the hot water come out of the taps
at the same rate as the cold does?

Please?

(And please forgive if this is a duplicate post - I seem to be having a sopt
of bother with News Servers too!)

On 24/10/2015 17:01, Aioenews wrote:
A while ago my heating system was changed from an open system with a header
tank to a sealed, pressurised system.

Last week a radiator in the bathroom sprung a leak so I decided to replace
it. Well, long story short, I called in a Plumber (lack of tools, lack of
confidence and lack of strength, in no particular order - me, I mean, not
the Plumber!) who recommended changing the valves along with the rad. This
needed the system to be drained, so he found the stop cock and did so.

It didn't seem to take very long to drain down and despite the drain point
being at the lowest elevation none of the downstairs radiators drained out.
On completion of the job, he opened the cocks on the filling loop,
re-pressurised the system and turned the boiler on again. To my surprise,
none of the radiators either upstairs or down needed bleeding - apart from
the new one - either then or now.

I understood how the old gravity system worked, but I am struggling a bit
with the sealed, pressurised system that I have now.

Firstly, why did so little water run out when he "drained the system"? And
if the system is pressurised, why doesn't the hot water come out of the taps
at the same rate as the cold does?

Please?

(And please forgive if this is a duplicate post - I seem to be having a sopt
of bother with News Servers too!)



A number of us answered your earlier post. If you didn't see the
replies, chances are that you won't see this either!

If you *do* see it, look here for the answers:
https://groups.google.com/forum/#!to...-y/yo37CuUp2MA

--
Cheers,
Roger
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Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 24/10/2015 17:01, Aioenews wrote:

Firstly, why did so little water run out when he "drained the system"?

He probably closed the valves on the radiators.

And
if the system is pressurised, why doesn't the hot water come out of the taps
at the same rate as the cold does?

Its the heating side that is pressurised and that is isolated from the
hot water side so there is no change there unless you fit a nice shiny
expensive mains pressure hot water cylinder.