New bathroom installed last week. Noticed a loud banging noise downstairs and took me a while to realise it's coming from the new toilet cistern upstairs. It makes two noises in close succession about every two minutes day and night regardless of whether it's been flushed or not. So what I hear you say... well... in the living room the noise sounds like a bomb going off. It's really loud and we're cracking up!!

It's a Nabis toilet. Is it meant to do this or can something be adjusted in the cistern?

Thanks!!

It sounds like you have a bad flapper or not adjusted properly,Feel around the flapper flat edge. If it's wavy or you feel rough spots replace the flapper,
The linkage between the flapper and the flush lever should have 1/4" play when the tank is filled. Also, check the small tube coming out of the top of the ballcock and make sure it's connect to and draining into the white overflow tube. A bad fill valve seal will give problem too but first check the flapper first if the problem still there let me know and will tell how to check or replace the fill valve seal, good luck.

John