It was full steam ahead as one runner arrived to change the battery at Mr D's home.

Once the source of the pesky beep was idenitfy it was a quick trip in the car (bon) to purchase replacement batteries.

Bish bash bosh new battery fitted....waiting with bated breath....and unfortunately I was monoxide myself when it still beeped.

A quick google later and I had located the contact number of the manufacturer and it was honeywell systems go for Mr D to give them a call and order a replacement unit tomorrow. No need to be Alarmed after all.