What can I do with a plastic consumer unit

This installation has received a C3.

I am tempted to do nothing as an electrician has quoted about £600 to replace the lot with a board full of RCBOs.

Is there a simple way of improving the fire rating?

  • The EnviroBurst Automatic Fire Suppression System - £30. As an alternative to doing nothing. 

  • Generally, CUs  don't just spontaneously combust. Usually it's due to a poor termination causing overheating. So get someone who knows what they're doing to check that all the connections in the CU are at the right torque settings (or "suitably tight" in the absence of torque specifications), and that nothing looks to have overheated.

  • Ah! A nice tidy bit of work. C3 seems fair, but I wouldn't change it.

  • Agree. There's a lot of ill-informed panic nonsense bandied about over plastic consumer units.

  • There is also type AC RCD's to consider as well as the fire rating. Also lack of surge protection.  


  • Is there a simple way of improving the fire rating?

    The other approved approach is to enclose the plastic CU(s) in a cabinet or enclosure constructed of 'non-combustible material'.... (although if it were mine and looked to be in good condition internally, I probably wouldn't bother).

       - Andy.

  • Hopefully the termination tightness testing was done by the person who did the EICR, there is a tick box on the model form for confirmation this has been done . Also, signs of overheating should have received a code.

  • You don’t need to do anything, C1/C2 need sorting to get a satisfactory cert, C3 will not make a cert unsatisfactory. The regs are not retrospective as otherwise we would be changing every board for not having SPD/AFDD being plastic.

  • Based on my understanding, the original question pertained to an alternative approach when faced with plastic consumer units that do not meet the current BS 7671 standard for domestic installations. While it’s true that no immediate action is required, and a C3 recommendation will not render the certification unsatisfactory, improvement is recommended, hence the previous suggestions. 

  • It shouldn't be a C3 anyway unless it's under a wooden stair case or in an escape route.  If the under side of the wooden stair case is plasterboard that could possibly count as your fire barrier/compartment ?  A linked smoke detector could be a smart idea as well and could be a reasonable addition to the regs where such things are unavoidable.