Range from the cheapest replacement of a toilet float valve £20 (Krzysztof Zakrocki based in N18) to the dearest replacement of a float valve £90 (Supreme plumbing and heating based in N9).
Comparing plumbers estimates for replacing a toilet float valve in the cistern tank gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes to replace a toilet float valve in N18 by posting a job with HaMuch and we will send it to plumbers in N18.