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