In the trade for 30yrs working with all different sites/agents . Had my own interiors business for ten years which added more skills to my trade .Bathroom/kitchen fitting for various companies over the years, Mixing them all together I found gave the customer a wider range of trades which we do , it makes there choices of jobs which need doing easier ,as All in one can cover them all .
For us to be able to price this we would need to know the dimensions of the box itself , as we need to supply lead ? also is it an aluminium/timber box gutter .these answered would then save time and let me give you an accurate quote .
Is your bathroom a wet room ? is your stop cock in the bathroom and if so can you see running water from it .? do you know of any other pipework that could be causing this ?
To swap over a radiator and drain your system . re fill once fitted and re load with inhibitor will cost between £250-£290 .it will be more if there is any pipework to alter .
Sometimes there can be a loose connection in the holder as the slight movement can do this , also if it is a b c holder then try checking one of the spring-loaded contacts to see if it has stuck down ? if you are doing this yourself please be certain to isolate your electric first .
You can change the layout of your cistern . the kit you will get easy for an internal overflow , just be certain to get the right stopper for the hole where your old overflow drained through the wall .you can then cut away the pipe through the wall and fill it . depending where it is positioned (some people) put a vent over it which gives more air into the room .