We read about boilers, rely heavily on boilers and quite often curse the cost of boiler repairs and maintenance. But who has ever thought of a boiler being a source of extreme danger?

Last month, the term ‘back boiler’ became synonymous with danger for one unlucky lady. Susan Woods’ from Mansfield was calmly sitting on her sofa with a coffee when an almighty explosion ripped through her home, causing untold damage to her possessions and leaving Susan with bits of flying debris in her eye.  The bomb-like detonation originated in a disused boiler positioned behind her fireplace and the local firefighters said she was incredibly fortunate that a coffee table was in front of the fire, as the force of the blast could have, literally, chopped Susan in half.


“It’s a wonder I am still here,” she said.

“I was just sitting in the front room on the settee in front of the fire with my sister having a coffee and all of a sudden it was like a bomb had gone off.”

Her husband, had lit their Rayburn fire, as normal at about 2.15pm and an hour later the abandoned boiler exploded.


The dangers of back boilers

In the last five years there has been one fatality and three people seriously injured by back boiler explosions.

Solid fuel back boilers are similar to coal fires, consisting of a fire grate which holds material, such as coal, paper, wood for lighting the fire.

A jacket containing water sits behind the fire, and heats up, just as a main fireplace does.

However, when boilers are left in situ or sealed off, some water will remain and will eventually be heated to form steam, thus creating pressure.

The jacket becomes extremely hot – sometimes reaching 700 degrees Centigrade – and as internal pressure builds, without water to turn into steam, it can explode.


There are other long term potential dangers by use of a fireplace and redundant back boiler:


  • If connected pipework is left in situ, corrosion or cracking of the water jacket sidewalls may allow the flue gases to enter the pipework and be distributed to other areas of the property. The high temperature of the pipework may also present a fire risk.
  • potentially dangerous for structural damage through repeated expansion and contraction of the boiler casing.

A spokesman for Nottinghamshire Fire service said:

“We would urge anyone who believes they may have a disused solid fuel back boiler in their home to seek professional advice about the appropriate protection or venting of the system, or having it removed completely.”


images by nate, tsallam