Airlock to one rad?

[mjt81]

Hello knowledgeable folks!

We have a re-occuring issue with one of the radiators on our system. The rad in question is at the top of the house (rads on three levels) and is a towel rail. There is another rad on the same level, which we do not experience any issues with at all.

We repeatedly get an airlock somewhere leading to the towel rail (feed pipe remains cold) which I can successfully resolve in the usual manner (isolate feed and return valves, remove bleed point, attach hose, open flow/return until airlock clears, replace bleed point, re-pressurise system etc) however, this is a "faff" which I am having to repeat on a regular basis.

Three questions:

1) Anyone know what would repeatedly cause this to happen?

2) Anyone know how to solve it permanently

3) Would installing an autovent (like an Aladdin) on the bleed point help to stop this happening?


Thanks in advance

 

[Madrab]

I don't understand why you are removing the bleed point, attaching a hose and then open valves until air lock clears. Are you using the hose to force mains pressure down through the rad to clear the air lock?

If you are constantly getting an air lock then there must be air entering the system or gas being created in the system. Are you having to top the pressure up regularly?

 

[mjt81]

Sorry, maybe I should have added this to my original post. The hose is attached to a 1/2" adapter which I screw into the bleed point before I open the valves again and is used simply to allow water to drain out of the rad and down the loo rather than onto the bathroom floor.

Simply opening the bleed point has no effect as water comes out immediately, so to clear the airlock, (which is somewhere on the pipes before the rad as the feed pipe doesnt get hot) I'm removing the bleed point then allowing a greater volume of water/any trapped air to flow out at a decent pressure to clear the airlock.

Pressure seems fine. Hovers around the 1.5bar when cold. Only time I need to top it up is after I've let a load of water out following the above process.

If there is an easier way, I'm all ears....

 

[jackthom]

How long does this radiator work properly after being bled?

 

[mjt81]

3-4 weeks