Banging pipes when flushing or using shower

[Benjy1001]

Hello!
Bit of background: We live in a 3 storey block of flats on the top floor in a 1 bed, 1 bathroom flat (built around 1987). There is no gas supply and heating is via x3 storage heaters. We have a System boiler (?) with a tank in a cupboard next to the kitchen. The water pressure is quite bad and so we have a power shower.
Whenever you use the the power shower or flush the toilet there is a crazy banging noise from the pipes that lasts about 1-2 minutes - I think it's mostly coming from pipes close to the boiler.
While the pipes are banging, in most cases if you turn the kitchen sink tap off and on it stops the noise - seems weird but it generally works.
Can anyone tell me what the problem is and how it can be fixed. I'm praying that's it's not expensive, is it possible to give a rough estimate on price?
My understanding of plumbing is non existent - so if I do need to get a plumber is there anything in particular I should say or ask about?
A massive thank you to anyone that can help.
Thanks,
Ben

 

[island fling]

Has there been any water treatment works done nearby recently? Have you turned off your main screw down valve recently?
Sound to me like too much water pressure so you might need a pressure reducing valve installed. Could also be debris in the shower filter & toilet washer.

 

[Riley]

Pic of hot water cylinder please

 

[island fling]

Has there been any water treatment works done nearby recently? Have you turned off your main screw down valve recently?
Sound to me like too much water pressure so you might need a pressure reducing valve installed. Could also be debris in the shower filter & toilet washer.

Meant water mains work not treatment sorry.

 

[Gasmk1]

have you checked the tank in loft when its making the banging sound

 

[Benjy1001]

Hi all,
Here is a pic of the tank... I'm about 99% certain the noise only happens when the boiler is turned on... but not sure if that helps.
If you look to the side of the picture there are two switches which I use to turn on the boiler... not sure what they do individually. There's also a timer which I use when the boiler is on.
Above this is the other tank (cold water?).
I think the main screw is in a cupboard in the hallway... never really used this.
Thanks for all the help

 

[Benjy1001]

Just wondered if anyone had any thoughts about this? Is it simply too difficult to tell without looking at it?
Thanks

 

[Harvest Fields]

This is your hot water cylinder and not your boiler mate.

 

[Benjy1001]

Sorry mate, that's all there is in the flat... it's an electric system... what else am I looking for? Would it be outside the flat? In the loft (we're on the top floor) or hallway cupboard maybe?

 

[Harvest Fields]

You may not have anything else mate.