Both upstairs and downstairs toilets bang when cistern filled

[basq]

I'll get a video shortly but both of my toilets give a bit of a bang noise after cistern has refilled.

From looking online, I can see something about cistern potentially filling too quick.

Any thoughts without a video? I'll try and throw together a video later.

 

[just pumps]

Anything changed recently plumbing wise.
Cistern inlet valves come with a restrictor for high pressure.

 

[basq]

Don't think so.

It's been doing it since I moved in.. but it's not exactly loud enough to bother me.

 

[terryplumb]

Any isolators on supply pipework to wc ? You could try closing them down some. Will obviously take longer to fill Cistern after flushing though.
.........
By the way is the fan working now

 

[basq]

Any isolators on supply pipework to wc ? You could try closing them down some. Will obviously take longer to fill Cistern after flushing though.

Yeah, unfortunately there doesn't seem to be.

By the way is the fan working now

It is indeed.. worked once I swapped switched-live and live per your advice. Much appreciated again!

 

[dilalio]

Are both toilets the same inlet valve?
Are they torbeck type valves or older ball valve types?

Torbecks (or toilet silent fill valves) work by allowing full bore flow into the cistern right up until the end of the fill cycle and then shut off rapidly.

This immediate shut off is better than the seemingly never ending trickle that a ball valve produces but it can cause reverberations throughout the system pipework because of the shock it creates.
My upstairs valve does it but, with 5 of us at home I prefer the rapid fill time and don't even notice it any more.

Post pics of your valves and are they both mains fed? Did you change over from a gravity system to a combi or unvented in the recent past? When this is done, toilet valves often get missed out being converted from LP to HP which usually means new inlet valves as nobody keeps the supplied restrictors when the the units are originally fitted.