Toby wrote:
"NT" wrote in message
...
Toby wrote:
"Grumps" wrote in message
...
"NT" wrote in message
...
Grumps wrote:
Hi
The freezer door of our Bosch was left open last night, and the over
temperature
alarm sounded a few hours later. Now the unit can't maintain -18C
when
using its 'ECO' mode. Is that just a coincidence with the leaving the
door
open, or could that have broken something?

If its a frost free, a defrost cycle should sort it. Give it 24hrs to
hopefully fix itself, if not defrost manually.

It is. We've never done a manual defrost, just left it alone.
So the defrost cycle is automatic? What does it do? Am I being stupid?


The auto defrost either has a heater wrapped around the cooling part
inside
the unit, so when the defrost is activated, it stops cooling and the
heaters
melt the ice quickly - or the freezer has a valve in the refrigeration
plumbing that will reverse the process, so the inside is heated and the
outside is cooled for a short time, melting the ice.

They don't always melt it all though, and you can get a build up
gradually,
that turning it off and letting it all melt is the only real solution.

I had to the this exact thing with my 5 year old frost free freezer a
couple
of days ago (first time I have had to do it) - luckily we have a spare
chest
freezer we just moved everything to and then turned the main one off
overnight with the door open, stuffed with a few towels to absorb the
water
(which wasn't actually that much to my surprise)

Toby...


Ffffs do a defrost cycle every 8-24 hrs. If its timed it probably wont
clear it, if defrost end is determined by a thermostat it will.


NT

Even if it is by thermostat, then the stat can only sense where the probe
is, there still may be buildup somewhere in the system.

Toby...

The place that ices up is the evaporator, which is a big metal
heatsink. There wont be much temp gradient across that, and the
defrost stat is designed to wait till its warm enough to ensure its
clear.

Timed defrost cycles are designed to handle daily icing, and tend to
quit too soon to clear an overnight open door.


NT