I acquired this Dimplex heater as the previous owner had reported that it had tripped their electrics and smelled of burning, it was perfect material for the workshop. The owner had given up on it and I felt like I could give it a second chance. This is the usual way we end up with much of the stuff in our home.
Now, this heater is only a few years old and on the face of it, it looked in reasonable condition, with just a couple of scratches, so it would be a shame if I couldn’t get it working.
With electrical faults like this, I always check the basics; the condition of the flex and mains plug etc. I then measure for resistance to earth from either live or neutral to see if there has been any electrical shorts, that would have triggered the reported fuse incident. All clear.
Through the top heat vent, I had a quick look at the inside of the heater to see if any stray paperclips or other metallic item had found its way to the heating element or wiring creating an electrical problem, again, all clear.
Upon checking the mains plug again, something didn’t seem quite right. It felt a little ‘warped’. I’d already checked the fuse for continuity via the live and neutral (there was resistance), but it was time to take it out to have a proper look. The plug on this heater was a ‘moulded-on’ type, with no screws and the fuse carrier was accessible from the outside, should it need replacing. Upon levering the fuse holder out, the plastic carrier sheared off, revealing burned plastic and signs of melting. The plug was toast.
I decided to break the plug cover off and see what was going on. The plug had ‘run hot’ for some time causing the casing to melt and smoulder and the excess heat had probably caused excess resistance, exacerbating the problem, making the previous owners’ electrics to go pop.
With the cover ‘broken off’ the plug, I was then able to cut back the internal connections and remove the cable from the mouldings, without sacrificing the cable length, which was a good job as the flex was quite short anyway.
I always keep a few replacement ‘quality’ mains plugs in the workshop for occasions like this, as not all moulded plugs are terribly well made and the melted one I had here was a good example of what can happen when the quality of the plug can’t match the potential current flow required. The heater is rated at 3K Watts (max), which would mean a current of 12.5 Amps, which is close to the 13 Amps fuse fitted. Poor quality materials and connectors would generate excess resistance and therefore heat. The resistance was probably detected by the sophisticated minature circuit breaker in the previous owners’ electrics board, which was a good job as who knows what could have happend if the plug had been next to something flamable.
With a new plug fitted, the old fuse re-fitted, the heater sprung to life and didn’t seem to draw excess current when checked. A nice cheap fix and I didn’t even have to take the heater apart.
Cost of a replacement heater: £50 (circa) Cost of repair: One cup of tea.