The heat is on…

Dimplex DX300T heater gets repaired in the workshop.

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.

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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.

Morphy Richards smoky heater

A heater with a broken motor gets a clean up…

I like the classic, function-over-form design of this heater.  Simple, clear, chunky controls and nothing included that isn’t needed.  Less is usually more.

This 1980s heater, although very well made and clearly designed with longevity and repair in mind was a little bit, er smoky.

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Fixitworkshop, February’19, Morphy Richards fan heater.

It appeared that the fan wasn’t running and the smoke was coming from old dust which had settled inside the machine.  I don’t think that the heater had been used in many years.

The heater came apart very easily, just three self-tapping screws holding the sides together to the main shell.

On first examination that the shell was out of shape and that it had come in to contact with the fan itself, forcing it to far down the motor shaft on to the motor body.  So, all that would be needed would be reposition the fan and re-shape the outer heater shell, a simple fix then.  Not quite.

The motor did not spin easily and even with a little penetrating oil on it, it was turning slowly, with the mains applied.

The motor was an induction type, with no brushes and didn’t obviously have anything restricting the motor’s spin.  I know that even apparently clean motor parts can have deposits of unseen oil and muck that can stop an otherwise good motor from working properly.  In situations like this, I tend to use brake cleaner or similar to break down the dirt.  Once cleaned, just a couple of drops of sewing machine oil on the moving parts and that usually cures things.  I was in luck and after performing a mild service on the motor, it was spinning at full speed once again.  Quite literally warming.

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With the parts all back together, the heater was ready to run for many years to come.

Cost of replacement:  £15.00    Cost of repair:  £0.00, one cup of tea and a Bourbon.