When to stop bleeding a radiator?

pinkteapot

I've just bled my radiators for the first time, aged 38 3/4 :rotfl:

Question though... It's a new-build and three of the radiators are very tall (6') slim ones. Those three had LOTS of air in (which might explain the racket they've been making). However, after ages listening to the air hissing, I was then getting both air and water - fine spray of water and air.

I stopped bleeding them when it was more water than air, but they hadn't reached the point of being dribbling water with no air. Do I need to bleed them further? Although air was still hissing a bit, a fair amount of water was on the towel by the point I got to and I wasn't sure if I should keep letting it out... All the normal height radiators just dribbled water straight away with no air at all though.

(Yes, I checked the system pressure afterwards and topped it up as it had dropped below the red line )

pramsay13

There shouldn't be any air in the system so keep going until they are just dribbling water.

How long have the radiators been fitted for?

I have one radiator in my house that needs bled fairly regularly so it has air for a good few seconds, then the bubbly water, then just water.

-taff

When you put the heating on next feel the radiator. If it's still cold at the top, bleed them again.
With radiators in another house, they just keep spraying water, it diesn't dribble out...
In this one, it dribbles...

[Deleted User]

Hi,


I remember when bleeding brakes on a car to always start with the cylinder farthest away from the master cylinder, so maybe the same for radiators, farthest from boiler first.

pinkteapot

Cheers all! I'll have another go at those ones.

The radiators were getting warm enough all over, but we had loud echoy dripping noises coming from the heating when on.

The system was fitted in the summer into autumn. Hot water tank has a fitted date of 7 October on it but from visiting the house during construction the radiators were in before that. We got the keys in late November but the builders were using the heating for a few weeks before that.

ChrisK....._3

The highest radiator collects most air. Depending on where the pump is, some systems need bleeding whilst the pump/heating is on, others need bleeding when it's off. If you try it the wrong way then you can actually let more air in and not out

pinkteapot

Hmmmmm. I bled when the heating was off because the internet told me to! How can I tell which way round it is?

I've got the number of the plumber who installed the system so I can just ask him if needs be.