The thermostat is dead in my strange¹ fridge with no replacement parts. I posted about the mystery component before.

There is a metal plate that appears to sandwich a single small loop of refrigerant (guessing!). Mounted attached to the backside is a coil with a ground and two wires marked to handle 220v. One of the leads connects to the LOAD wire on house mains and the other to the (now broken) thermostat.

I can only imagine that it’s a heating element for defrosting (as suggested). But I struggle a bit with that theory because I’m surprised the fridge would ever get cold enough to justify defrosting.

Anyway, I wired the mystery coil directly to mains and left it for 10 min or so. The temp of the metal plate did not feel any different. Is that expected? Metal is naturally cold at room temp and that did not change.

I would like to understand it because I cannabalised a simpler t-stat from another fridge. The t-stat has no connector for whatever the mystery component is… it’s just a switch that connects two wires. I don’t know if I should just omit the mystery component, or if I should wire it in series with the new t-stat, or keep it attached to the old broken t-stat and wire that in parallel to the new t-stat.

¹ I say strange because there is no freezer-fridge vent. So the fridge is independently cooled.

  • bitfucker@programming.dev
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    8 days ago

    Yeah, that’s a broken heater. A broken heater sign is usually high resistance or good ol disconnect. It being in parallel further reinforces that. This is a common schematic for domestic refrigerators.

    Domestic refrigerator schematic

    • diyrebel@lemmy.dbzer0.comOP
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      8 days ago

      For the moment I just disconnected the heating element and wired in a t-stat from a mini fridge. The heatin element could very well have been broken as long as I owned the fridge (it was given to me as a quite old 2nd hand fridge).

      I guess I will keep my eye out for similar normal sized fridges that are trashed. Maybe I can harvest a heating element and combined t-stat like mine to recover the auto-defrosting function.