I`ve just changed my noisy Central Heating pump with no problems, but
have noticed a brass fitting located at the end of a copper pipe
coming from the pump .

It`s a 1" brass cylinder with a knurled screw end with a red plastic
unscrewable cap on top.

I`m assuming that it is some kind of venting system to remove air from
the CH circuit but how does it work.

Unscrewing the red cap and nothing appears to happen (no gush of air or
water )

I`ve got a normal bleed valve located at the other end of the pump
which can be used for manually bleeding the system using a normal
radiator key.
..

Any suggestions what this other fitting is and how it works?

TIA

shamblesforge wrote:
I`ve just changed my noisy Central Heating pump with no problems, but
have noticed a brass fitting located at the end of a copper pipe
coming from the pump .

It`s a 1" brass cylinder with a knurled screw end with a red plastic
unscrewable cap on top.

Automatic air vent. There is as float inside it which seals the outlet
when it is full of water. Air should be released on unscrewing the red
cap, providing there's air in the system. The red cap should be screwed
down a week or two after filling the system & no more air is in it.

Excellent answer!. Thanks.....Now I know

"Aidan" wrote in message
oups.com...

shamblesforge wrote:
I`ve just changed my noisy Central Heating pump with no problems, but
have noticed a brass fitting located at the end of a copper pipe
coming from the pump .

It`s a 1" brass cylinder with a knurled screw end with a red plastic
unscrewable cap on top.

Automatic air vent. There is a float inside it which seals the outlet
when it is full of water. Air should be released on unscrewing the red
cap, providing there's air in the system. The red cap should be screwed
down a week or two after filling the system and no more air is in it.

The above concise reply should be on uk.D-I-Y plumbing/heating/FAQ.

On 5 Dec 2005 07:20:17 -0800, "Aidan" wrote:


shamblesforge wrote:
I`ve just changed my noisy Central Heating pump with no problems, but
have noticed a brass fitting located at the end of a copper pipe
coming from the pump .

It`s a 1" brass cylinder with a knurled screw end with a red plastic
unscrewable cap on top.

Automatic air vent. There is as float inside it which seals the outlet
when it is full of water. Air should be released on unscrewing the red
cap, providing there's air in the system. The red cap should be screwed
down a week or two after filling the system & no more air is in it.


If it's like one of these

http://www.rwc.co.uk/Product.aspx?page=CAT5

(number 10)

then yes.

On the Honeywell equivalent one, you can also rotate the upper part of
the valve body to isolate the valve completely


If it's

(number 11)

then the red cap is purely a protection.

Unscrewing the cap merely reveals a button inside that can be pressed
to manually operate the vent.


--

..andy