The pump wasn’t turning off except at the mains; a “saniflo plumber” was called who arrived with his iphone. A picture of the pump was taken and was told it was the flow/float valve which would be ordered and fitted in due course. Alarm bells rang, not to mention the inconvenience and I found Acorn Engineers. Pam and partner arrived that afternoon, fitted a new diaphragm, cleaned up, gave advice on what to use – and what not use! Very reassuring, a job well done, can’t recommend them enough. Thank you!!