Black box in old consumer unit - electrician stumped.

[alexkx3]

Can any of you old pros out there help identify the middle black box made by Engel and Gibbs ltd. It buzzes sporadically, even when the main supply to the flat is off.

My electrician has never seen it before and can't figure out.

Thanks,

Alex

 

[Noaksie]

Engel and Gibbs blast from the past it will normally to control heating load & can be linked to off peak supply. Some of these units contained asbestos.. beware. By the look of the photos this install needs serious updating. The buzzing is due to the age of the coil. This must be 40 years old at least

 

[Noaksie]

Engel and Gibbs blast from the past it will normally to control heating load & can be linked to off peak supply. Some of these units contained asbestos.. beware. By the look of the photos this install needs serious updating. The buzzing is due to the age of the coil. This must be 40 years old at least

 

[Last plumber]

@mrloy99
What bad spelling?