The Strange Noises Radiators Can Make…
You can sometimes make the whistling stop by turning the radiator valves fully on – you’ll need to turn the valves anticlockwise. It sometimes happens when the water flow rate is either too high or too low.
A ticking radiator is completely normal – it’s just the radiator warming up or cooling down. If it’s coming from under the floor, it’s probably pipes expanding and rubbing on the floor or joists. It’s nothing to worry about.
Tapping or Hammering
You should get in touch with the person who installed it to get them to fix it. It usually happens if someone hasn’t fitted a thermostatic radiator valve properly. So if you’ve moved a radiator or had a new one put in recently, it could be that the valves might have been swapped over by accident.