air in radiator

[harbottle]

Hi, I have a towel warmer/radiator in my bathroom and the problem is it needs bleeding around once a month. Because of its shape it is the highest rad on the system. When I bleed the air out it's fine but within a month the top third is cold again. Can anybody tell me why this may be happening and how the air is getting in the system.

Thanks

 

[Bankrupt]

Most likely it's hydrogen that's being produced due to corrosion in the system.

Has the water been dosed with inhibitor ?

 

[harbottle]

There used to be inhibiter in but I had to drain the system about 1 year ago and never put more back in, I will put some in and see if it makes a difference. Can it make so much gas in such a short time? and what part exactly is likely to be corroding?

 

[Maxsys]

Can it make so much gas in such a short time?

Yes

and what part exactly is likely to be corroding?

The inside of your radiators

 

[harbottle]

Thanks for your answers, I will try your suggestions and see how it goes.