Celebrating my ninja central heating fettling skillz.
House was cold this morning, digital thermostat had a blank display. Hmm. Fitted new batteries, no joy. Found over ride switch, got house tolerably warm. Looked up replacement stats on interweb, saw pricer, felt unwell. Turned off heating, went to Science Museum.
Got home, dissected digital thermostat with trusty Opinel. Found corroded battery contact. Cleaned. Reassembled. The thermostat, she lives, for I am a fettling god.