Radiator seems to fill every 30 mins? banging?

[buckaroo]

I am working from home at the top of the house in a converted attic.

As this is the top of the house, I usually bleed the radiator quite often due to air pockets which is fine and the Radiator gets hot.

This is a new radiator, but it seems suddenly every 30 mins or so while the heating is on, the radiator bangs and crashes for 20 seconds, with water flooding and swooshing sounds? quite loud too?

There are no leaks or anything for concern, but is there a reason why this started, and whats causing it? its quite loud in the room when it does this, every 20-30 mins or so as if its filling up violently?

Any thoughts or help?

Thank you.

 

[oldbuffer]

One possibility is a lot of air in the system, which suddenly reaches your problem radiator. Let the system run for half an hour or so, then turn it off. Wait 15 minutes to make sure the pump has stopped, then:
a. Bleed every radiator. I'd start at the bottom and work upwards.
b. If the pump is separate (i.e. not in boiler), then if it has a chrome screw or hexagonal bolt right in the centre, slacken that screw / bolt to release any air. Do NOT remove it altogether. Have some old towels handy to mop up what should only be a little bit of water.
c. If you have a hot water cylinder heated by the boiler, make sure it has no air in the coil. There may be an air bleed point attached to the upper connection to the coil in the cylinder. If so, release any air either by undoing the thumb wheel (if it has one) or slacken any cover which looks like a car Schraeder valve cap. If there is no air bleed point, you would need to carefully slacken one of the compression nuts in the pipework leading to the upper connection to the coil. Do NOT slacken any connection directly attached to the cylinder, you run the risk of not being able to do it up again!
d. While doing any of the above, make sure any motorised valves are in the open position. They normally have a manual operating lever for this purpose.

 

[buckaroo]

Thank you.

I've also noticed, that as the hot water tank is up in the loft too, that it has been overflowing out into the side-entry outside.
Is this also caused by the radiator and the noise/air lock?

I am bleeding it now, and will do the steps above bleeding from the ground up, all the radiators in the house, to the top of the house.
Would this also stop the water overflow outside?
(we just had the water tank ball float changed and adjusted a few months back?)