I have been getting some noise apparently from my central heating system and tried to bleed air, if any, from the radiators. These are probably quite old but have not been a cause for concern during the three years I have been in my flat. The problem I have encountered is that, while I am able to slacken off the screw on some of the radiators using a key intended for this, there are others where the key does not get a proper grip on the nut. I have tried, without success, using tweezer like pliers but there is limited space in which to work. Can anyone please suggest how best to deal with a problem of this nature. The last thing I want to do is to have to replace any of the affected radiators.
Alaric