Keston Combi C40 boiler’s sudden explosive ignition

Hi Folks,

My Keston Combi C40 boiler, which is nearly six years old, is facing an issue of a sudden explosive ignition. It is quite dangerous. I do not know what happened with the boiler therefore, someone please share his/her views who has shared this problem.



Hi Josh, before coming to the main point, it is important to note that the problem of a sudden explosive ignition should be fixed instantly. Well, you are facing this issue due to the following reasons:

  1. The boiler’s slow ignition switch is out of order
  2. Compressed pilot flame

You can fix the problem by focusing on the following ways out

  1. If you suspect the slow ignition switch is damaged, try to replace it
  2. In case of a compressed pilot flame, try cleaning or replacing the boiler’s pilot widget assembly