No such things as stupid questions, Kelly - but there maybe stupid answers!
From this distance its impossible to know if the tank stat is actually connected to anything, but we'll assume it is. If the water in the copper cylinder is too cool then you wont have enough hot water to serve your home, so the water is made hotter in the cylinder so at the sink or bath you add more cold to get the temperature you want - therefore 60 deg is the norm. However, if you are happy with what you have then you may wish to leave it be.
I would think that your noise is there all of the time - just in the daytime there is too much background noise for you to hear.
For obscure noises such as these, we can use a stethoscope to track them down - but thats really only for anorak and flat cap wearers
Happy hunting!
John
From this distance its impossible to know if the tank stat is actually connected to anything, but we'll assume it is. If the water in the copper cylinder is too cool then you wont have enough hot water to serve your home, so the water is made hotter in the cylinder so at the sink or bath you add more cold to get the temperature you want - therefore 60 deg is the norm. However, if you are happy with what you have then you may wish to leave it be.
I would think that your noise is there all of the time - just in the daytime there is too much background noise for you to hear.
For obscure noises such as these, we can use a stethoscope to track them down - but thats really only for anorak and flat cap wearers
Happy hunting!
John