by ericmark »
Tue Nov 06, 2018 12:13 pm
There can be many reasons, but first the easy one, blocked drain pipe, the idea is the cooling bits are separated from the main body of freezer and a element is included so every so often the freezer stops including fan the element switches on it melts all the ice which drains down a pipe onto a tray on top of the motor so tray gets warm and water evaporates from the tray once motor switches on again.
What I found was a standard defrost would remove all the ice you can see, but there would be ice blocking the drain hole, so it would build you quickly again.
So I would use a standard desk fan in freezer to circulate the air while defrosting, this helps speed up the defrost, and I would move freezer away from wall enough so I could put my finger in the tray, also needed to do that to unplug, only once I can feel water in the tray would I return it to service, if nothing after a couple of hours it was a remove all covers job to poke the hole clear.
I found I needed a defrost around once a year, and the fridge/freezer needed me to call out the repair people many times over it's life, approx once every 3 years, when it was around 15 years old it played up again, however my wife called the repair man before I had chance to defrost it.
When he arrived he looked at ice and immediately condemned the unit, it seems there was a fault with the insulation, this means room air can get through the insulation and ice builds up, ice conducts heat better than insulation so the fridge/freezer has to work very hard, this means the cooling bits are much colder than normal so the heater does not have enough time to fully defrost them.
It seems likely the fault was there from new, today I every so often plug the fridge freezer into an energy meter, maybe for 3 or 4 days, it records kWh used and how long under test, so simple maths kWh / hours under test x hours in a year = kWh/annum this is quoted in the adverts, so if it should use 200 kWh per year and you have worked it out at 230 kWh then likely OK, however if it works out at 300 kWh per year, likely insulation damaged or gas lost.
Not a perfect method, but good indication. Also freezing point of brine is -18 deg C and freezer runs at -18 deg C so if a tray of salt saturated water does not freeze too warm, but freeze solid then too cold, I had one freezer where the thermostat had failed so was far too cold, this will also show up as freezer using too much power.
But first thing is ensure the drain hole is clear.
