we have a central heating system which is 15-20 years old. At the end of the pipework feeding many of the radiators is a partially recessed square nut below which is a spout which I guess is for bleeding the pipework. Some of these square nuts periodically work loose and need to be tightened. And here the problem starts. I have a heavy bronze type allen key which I think came with the central heating system in the shape of a triangle and at each end a different sized allen key marked, 1, 3/4 and 1/2 respectively. I am not sure what these figures refer to as the actual size of the square nut is 7 mm square. I have used this allen key in the past with great difficulty to tighten up some of the nuts as the bulky triangular shape makes locating it square over the nut virtually impossible as it fouls up with the wall and pipework which are very close and restrict access. What I need is just 1 allen key of the right size which will allow access in a restricted space. In the past after much faffing I used either the 3/4 or 1/2 size on the triangle but am mystified how this relates to the 7 mm square nut sizewise.
Would be very grateful for any help and what to ask for. Also can anyone recommend good internet companies who sell this type of product.
Many thanks, Regards, Frank.
Would be very grateful for any help and what to ask for. Also can anyone recommend good internet companies who sell this type of product.
Many thanks, Regards, Frank.