Air in Radiator

Gorteen

Registered User
Messages
32
Every year at this time, when I begin to turn on the oil-fired central heating, I find I have to drain one or sometimes two radiators. Is this normal?
 

Leo

Moderator
Messages
10,361
Get someone to check the pressure vessel, make sure the feed loop is closed tight once the system is topped up..
 

Peanuts20

Registered User
Messages
109
I had to do it for many years but not since I changed boilers last year. In my case I guess the air was getting in somewhere there
 

JohnJay

Frequent Poster
Messages
880
Every year at this time, when I begin to turn on the oil-fired central heating, I find I have to drain one or sometimes two radiators. Is this normal?
do you only have to do this once a year? If you do, it doesnt sound like too much of a problem. If you had a leak you would need to bleed the rads more often.
 

NewEdition

Frequent Poster
Messages
195
Should you bleed a rad when they are hot or cold? I have had mixed advice over the years.
 

Jazz01

Frequent Poster
Messages
709
Should you bleed a rad when they are hot or cold?
Don't think it really matters - but I am open to correction! . You only really notice a cool area on the rad when the heating is on, so I would have done it when the rad is hot.

Just be careful if you are doing it when the rads are hot, any water coming out will be hot!!!
 

NewEdition

Frequent Poster
Messages
195
My point exactly.. there seems justification for both methods.
Hot makes sense though as the air is being pushed out by the pressure.
When cold, there is no pressure so the air wont be forced out.
 

Leo

Moderator
Messages
10,361
When cold, there is no pressure so the air wont be forced out.
If you've no pressure when cold, you have bigger problems. You need to open the filling loop while bleeding to allow water in to replace their air, the pressure from the feed (likely a header tank) is all you need. That valve then needs to be shut tight once done.
 
Top