Boiler mate tank grinding noise

[robbieross]

Hi everyone

Had a new boiler fitted a few years ago all fine.

we have a boiler mate big tank however in the airing cupboard and also a tank on the third upper floor / loft.

the boiler mate however is in the en-suite and is now very frequently making a grinding noise for a few seconds but very loud and waking us up in the night - can’t work out if it’s the timer clock or the pump or something else ?

Any ideas - going to smash it all up in frustration whilst in lockdown with no one able to come and fix ?

 

[Stu-B]

Could be a 2 port valve opening, difficult to diagnose without seeing and will depend on your set up... timers/zone valves etc.
Is it a the same time every day, say when the heating kicks in?

 

[robbieross]

Could be a 2 port valve opening, difficult to diagnose without seeing and will depend on your set up... timers/zone valves etc.
Is it a the same time every day, say when the heating kicks in?

it’s more through the evening / night which makes me think it’s when it’s colder and the heating is on/ off to warm the house up.