when my central heating is on every minute or so for about 5 seconds the rads make a knocking ( or dripping ) sound then all ok for another minute.
i have just puth them all back on after decorating and bled them, any ideas please, its annoying me!!!
whn rads are on the2 uptairs in the front bedrooms every minute or so for about 5 seconds make a dripping noise i have bled them but to no avail any ideas ?