Review on Zerostart 3400017 Electric Heat Magnet Heater for Transmissions, Oil Pans & Small Engines | CSA Approved | 120V | 200W by Chris Lemm

The biggest problem I see is the large air gap between the heating surface and the motor (see pictures). Without continuity you will never get your engine/oil/surface/whatever hot. The surfaces have to touch, otherwise you can just use a lightbulb and good luck with that. I hooked it up to a nice clean and shallow oil pan that only holds 3 liters, in a barn, air temp around 18*F. After 3 hours there was no heat in the pan. It wasn't as cold as outside, but not warm at all (wish I could use an infrared heat gun at this point). I decided to disassemble the device and grind the magnetic plates (see pictures). Using a ruler and feeler gauge, I found that removing .050" would now keep the heater surface in direct contact with the oil pan (see pics). RESULTS: In the barn, air temperature 18-20°F, sump started working at 20°C. F, after 1.5 hours the sump was 45*F (using an infrared thermometer). I would allow at least a few hours "before launch" to get a usable amount of heat. Now I'm happy with the heater after working on the magnet/stand issue.