Hot Water Storage Tank Noise

[dumptyhumpty]

Hi, clueless about all things plumbing related so came here for some reassurance more than anything.
Just recently there's been an irregular rapid clicking/buzzing coming from the bottom of our hot water storage tank.
Seems to start in the mornings once folk have showered etc., clicks/buzzes for a couple of seconds then stops. Goes on for a few hours then silence. When I put my hand to the bottom of the tank you can feel vibrations at the same time as the noises.
Any ideas?

 

[Puddle]

Well I presume you heating motorised valves and pump are also in the airing cupboard, this is probably were the sound is coming from
Your hot water motorised valve may be a actuator type, that moves round slowly to open and close, maybe this is sticking or worn with old age,which would cause the sound you hear, the vibration could just be the pump running
If it is the valve making the sound, it is on its way out and will require replacing, so get your friendly plumber in to sort out ,it will be cheaper sorting out now than waiting to winter time and doing on call out basis

imho

 

[dumptyhumpty]

Thanks for that, things about 10 years old now so bits are sure to be on the way out by now.
Much appreciated,