Combi boiler making a 'clicking' sound?

[ellie77]

I got a new combi boiler a few months ago. we had a few teething problems with vibrating Trv's but it seems Ok now. however, since we haven't had the heating on for a month now because the weather has been nice, whenever we use hot water or today I have put the heating on for the first time, it keeps making a sort of clicking sound, it sounds like metal when its cooling and so I would assume that this is what it maybe is? When the water is used intermittently or when it heats up, am I right?!!
Also, even though it doesn't get below 5 degrees at night anymore the boiler still fires up throughout the day and night, is this normal and why?

 

[Dan Robinson]

And what boiler is it?

My crystal ball is in for repairs.

The intermittent firing could be a preheat for the hot water.

 

[peterperfection]

I got a new combi boiler a few months ago. we had a few teething problems with vibrating Trv's but it seems Ok now. however, since we haven't had the heating on for a month now because the weather has been nice, whenever we use hot water or today I have put the heating on for the first time, it keeps making a sort of clicking sound, it sounds like metal when its cooling and so I would assume that this is what it maybe is? When the water is used intermittently or when it heats up, am I right?!!
Also, even though it doesn't get below 5 degrees at night anymore the boiler still fires up throughout the day and night, is this normal and why?

Noise is pipes expanding & contracting.
Nothing at all to worry about .