Mtb1953he fridge not cooling before it stopped fridge was making loud popping noise, i unplugged it then plugged it back in a day later to unthaw and fridge worked for 2 weeks now not working again. there...
It sounds like your defrost circuit is having a problem. Once frost builds up on the coil in the freezer compartment, air can no longer be pulled though the
fins and circulated into the fresh food compartment. You notice things start to
warm up. Eventually, the freezer suffers from the same lack of
circulation and contents begin to soften and melt.
The defrost circuit consists of 4 main parts. They are: 1) defrost heater, 2) defrost terminator or sensor in series with the heater, 3) defrost timer and 4) wiring between the previous 3 parts.
The defrost heater is found in the compartment that houses the coiling coil. The defrost terminator or sensor is clipped or otherwise secured to be kept in physical contact with the cooling coil itself. The defrost timer may be located anywhere the manufacturer decides - a popular spot is in the toe space on the bottom of the fridge. The wiring, well, that is between all the parts. Chances are the wiring is fine - as would be the connectors to the individual components.
The defrost timer runs about 8 hours. About 20 - 30 minutes in that 8 hour period the defrost switch operates. This consists of switching power away from the compressor (so it shuts off) and to the defrost heater and defrost terminator. The heater is just a relatively small value heater that warms the compartment to melt any frost or ice from the cooling coil fins. It will be powered for up to 20 - 30 minutes by the timer or less - if the defrost terminator senses a rising temperature on the coil. This means that the heater will be on for either 20 - 30 minute OR until the defrost terminator gets warm enough.
If the timer is stuck - and never moves to the 20 - 30 defrost cycle, the frost on the coil will never melt away. If the timer does work, but the heating element has failed, the frost will never melt away. If the defrost terminator has failed open (preventing the power from getting to the heater), the will not work to melt the frost off the coil. If there is a loose, missing or damaged connection between the wiring harness and these components, it won't run as expected either.
Make sure there is continuity through the heater. When cold (below freezing) the terminator should also have continuity. Many are designed to open around 50 degrees F - so if you warm it up, you should see the continuity go away. The timer needs power to run, and will send power to either the compressor or defrost heater - never both at the same time. Check with power disconnected. Use care checking live circuits - and only work live circuits when you need to check for presence of power - otherwise, unplug!
I hope this helps. Please rate this reply - thanks!
Jan 05, 2011 |
Maytag MTB1953HE Top Freezer Refrigerator