Noisey Central heating

[Tel77]

I've been doing some work in my bathroom which includes putting in an additional towel rail(pipework now installed and capped ready for final installation) but eversince I have de-pressurised and re-pressurised the system to plumb in the pipework for the towel rail I have noticed that the central heating seems to be a little noisey.

It seems to be making a ticking noise which could almost be interperated as a dripping noise(it's not though as have checked this).
Could it be that the system is over pressure despite the gauge showing it to be within the green?
The system is a sealed pressurised system with a filling loop by the way.

 

[stem]

Most likely it's because metal pipes that are expanding because of being heated by the hot water flowing through them, are touching something else such as a joist or floorboard. Usually separating the pipe by packing the offending areas with insulation will cure it. Radiators themselves can 'tick' as they heat up, but there's not much you can do about that. New radiator brackets often have plastic inserts to prevent metal to metal contact between the radiator and the bracket.

 

[Tel77]

many thanks for the info stem, I understand that the copper pipes may expand and contract but unfortunatley I don't believe this is the case as they are plastic with the exception of the tails through the floor to the towel rail valves.

The other odd thing is that the noise appears to be coming from several areas as well. I couldn't swear to it but I don't recall noticing any noise before I worked on the system which is why I queried whether it could be pressure related.

 

[dumbrill]

I understand that the copper pipes may expand and contract but unfortunatley I don't believe this is the case as they are plastic .......

The thermal expansion in plastic pipe is around 10 times that of copper.

 

[Tel77]

Thanks for the info. Sounds like it's normal and acceptable then. I was just worried as I'd not noticed it before I done any work on the system.

I guess it makes sense that it's probably going to be worse this time of year when the temperatures are as low as they are anyway.