Update is house was roasting all weekend, everybody noticed immediately on entering the hall, the playroom which never got really hot on range and was toasty. So whatever he did, its improved the system. The grit in the bath disappeared and the noises all gone.
I asked my husband but he not fully aware either of what plumber did. he cut two lengths of copper pipe (the size of mans arm) between the cylinder and the ceiling and put in a egg cup like gadget onto the pipe. He kept talking about some "Loop".
We hav a €75 receipt from a local hardware for the pump,
Leaky got the name from all the work he did on local estates (just qualified at the time), terrible plumbing issues (in a family member who was renting one of them, whole ceiling in sitting room destroyed as toilet, hand sink and square shower leaked, bits under the sink leaked to the point kitchen doors wouldnt fit into the cabinet to close as they had flush look/design, hot tap has cold water label so u must remember to twist the cold tap to get ur hot water in bath.. ) ,
will check 4 the mouse, oh my god, douth its that as we'v never had that issue....