Our fridgemaster mtrl170 fridge had a build up of ice in the top of the fridge. While I was away my partner took the fridge outside to defrost it and found the drip tray at the back was full of water and muck decided to tilt the fridge and drain the water and muck out. Took it back inside and switched it on. The light came on and it clicks at the back but it doesnt work. Switched it off for 24 hours to let the gas settle, but its still not working. Any idea???

No this time the fan was the cause of the ice build up and the fridge will be damaged if the fan problem is not resolved. What is the model number of your fridge?
APPLIANCE 911

The defrost timer has quit.
They have a relatively short life.

clean the backside fins of the fridge..they get gummed up with dust and cannot cool the water effectively..clean inside and especially outside back and bottom..also..defrost it fully first..

This could be a double problem.
Yes the auto defrost cycle seems to have failed allowing an ice build up.
Secondly the door seal is leaking allowing warm moist air to sneak in. You probably need a door gasket too.

try to clean the drain of your unit maybe it is clog up declog it to avoid drip. u said that ther is a build up of ice this means auto defrost not activate try to chek the defrost heater or defrost timer if have the unit this. or try to allign the door gasket possible theres a gap entry of outside air cause of build up of ice. bec it is came from moisture of air out side or avoid to much door opening.goodluck.

This is what is happening. All "frost free" refrigerators are not truly frost free. The cooling comparment elements frost up with moisture from the air. Every 6 or 8 hours or so the fridge shuts down. then . small electric heaters fitted into these cooling elements melt the frost away. The water goes down a tube into what is called a drip pan mounted underneath the fridge. If the drain tube clogs with a piece of paper, or food or algae. The water from the frost melting stays in the pan because the drain is clogged. So each time the fridge defrosts, it builds up ICE not frost and eventually it completely clogs with a block of ice.
The other thing that can happen, is that the timer that controls this cycle fails and the heating elements never turn on. The the fridge then clogs with frost. The fridge will clog with frost if any of the following parts fail. The defrost thermostat which opens up the heater circuit when the coils reach
around 40-50 degrees, the defrost heaters mounted in the cooling coils, or the defrost timer fails.
If your fridge works normally after this, then the drain hole was clogged and you unclogged it. If it gets colder and colder again. Then the timer, defrost thermostat, or the defrost heaters have failed.
Hope this helps. You are welcome to write back to me and tell me what is happening with your fridge. I hope this helps, Best Regards, Mark

Hi,
Some ice build up is normal, but it should go away when the unit defrosts...if it continues to build then the defrost is not working correctly...
Check out these tips...they can help you figure out what is going wrong withyour refrigerator and why it is not cooling

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heatman101

whatever,it cant not help,as long as you do a COMPLETE defrost(leave it for at least 24 hours.then dry out thoroughly.clean any drains/vents then restart as new.let it settle for at least 24 hours then check/refill.fridge is +5C...freezer is -18C,optimum temps...

inside the fridge there is a cold radiator which has filled with condensation or water from freezing it when say cleaned out the fridge this can be remedied by letting set for a few days outside in the sun so that water can evaporate properly or you can call a repair man and he can pull out frost radiator inside and defrost all the water out by dry wet vac and heater dryer

ice builds apon ice even a little bit can build up to a mountain same thing happended to my top end whirlpool i pulled the metal grate and defrosted this by pouring tap water over the ice which it went down the defrost tube outside water drain this helped greatly havent had trouble with ice since

a defrost problem, is gonna cause excessive ice build up in hte frezzer lower compartment. for somereaon the hdefrost heater was not energized. most common reason is a bad defrost thermostat, clipped on one of hte evaporator coils has gone bad,