Pressure Head by J.L. Merrow
J.L. Merrow’s Plumber’s Mate Mysteries series consists of six books written between 2012 and 2021 (and I don’t know if book six was the final one) and the PoV character is indeed a plumber, Tom Paretsky, who lives and works in a village near St. Albans in Hertfordshire. But he’s a plumber with a difference;…