Frost Free Freezer Repair

"I'm off to the General Assembly.  Feed the gerbils, and can you fix the freezer when I'm out?"  Is this the sort of conversation that is supposed to take place in a manse?

All we ask is that the white goods last until we get a manse.  Once there, either white goods will be included, or we can consider whether we need a replacement.  I certainly don't want to pay for a freezer that I'm only going to need until October.

So when the ice cream came out of the freezer a little softer than it should, we knew something was up.  Then the high temperature light came on.  Then it went out. Then it came back and went off again.

I checked it with a thermometer that I threaded through the door, and in the space of an hour or so, the temperature went from -18c to 9c, a 27c increase.  There was something seriously wrong with the air temperature inside, as if there was a heater running.  So it appeared that it was freezing, then occasionally getting briefly warm.

Bracing myself to have to spend £300 or so on a new freezer, I hit Youtube and found an instructional video showing me common problems.  It seems that for a frost free freezer to work, there is a heating element on the cooling element.  When the cooling element gets covered in ice, the heating element comes on briefly to melt the ice.  If the ice buildup is too much, then the heater can't cope, and the cold air won't circulate.

With nothing to lose, I emptied the freezer and removed the ductwork inside at the back.  Actually it took a bit of warming with a heat gun to get the duct off, the first sign that I was heading in the right direction.  When I looked inside I saw this...

Frost free freezer?  I don't think so.

A couple of inches of ice below the coil, and the bottom two rows of fins completely blocked. Air is meant to circulate through here, so I can see why it's not working.  An hour or so of gentle heating and a little dose of my magic spray and the whole thing looked a bit more normal.  Underneath that mass of ice there was a drain hole which is where the condensation flows out.  It looked like the drain hole had blocked, then progressive layers of ice built up to the point where it blocked the coil. I extracted over a litre of ice

Ice, Ice Baby?  Not here.

So a quick dry of all the internal surfaces, a check that the drain was now clear,  and a short reassembly later and the freezer is back to its normal -18c goodness.

So how many people replace their fridge freezer when, all it really needs is a complete defrost?  It might take a couple of says to melt out all the ice, but it's cheaper than a new freezer.

Am I too late to say do not try this at home, no user serviceable parts inside etc...?