Four fire engines and 25 firefighters tackled a flat fire at Rothwell Street in Primrose Hill.
A ground floor bathroom within the four-storey terraced house was partially damaged by fire. Thankfully, no injuries were reported.
Residents were alerted to the fire by smoke alarms and evacuated before the Brigade arrived. A London Fire Brigade spokesperson said: “This incident shows just how important it is to have working smoke alarms fitted on every level of your home.
“Smoke alarms give the earliest possible warning when a fire starts and we would urge everyone to make sure they have one fitted in every room where a fire can start except kitchens or bathrooms where heat alarms are more appropriate.”
The Brigade was called at 1019 and the fire was under control by 1118. Crews from Hornsey, Kentish Town, West Hampstead and Paddington fire stations attended the scene.
The fire is believed to be accidental and caused by an electrical fault in the underfloor heating.