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An "engineer" has recently investigated my 10+ (that's my estimation - we bought it together with our apartment) year old Smeg FB30 refrigerator and claimed that the coolant gas is leaking from the pipes at the back. He did the diagnosis by blowing hot air from a hair dryer at the back of the refrigerator (the gas pipes are running beneath a plate at the back). When the heated back plate started to yield under pressure in one place, the repair guy said that coolant gas is leaking and he recommended to replace the refrigerator (as it is quite old).

I have some doubts whether this is a serious diagnosis. Do people test refrigerators for gas leaks in this way, or was the guy just, well, blowing hot air?

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This is amusing. No, I cannot think of how a hair dryer could be used as the key diagnostic tool in determining a refrigerant leak in a refrigerator.

That said, I have used a hair dryer on several occasions to accelerate removal of ice where a "frostless" fridge had a malfunctioning defrost cycle and ice had accumulated on the coils (caution: do not try this unless you know to avoid potentially heat sensitive parts). Certain vintage GE units were notorious for this about 10 years ago. Those units had several temperature sensors that would go bad, failing to regulate the temperature and activate the defrost when required and also they had main control boards that would go bad, failing to run the condenser fan as required.

The common signs of a leak are: (1) The unit is low on charge, causing poor performance overall and the evaporator coil very rapidly accumulates ice progressively from one end until the whole coil is coated, and (2) trace amounts of oil around the area of the leak, although this is sometimes impossible to find. To find such a leak these days, one would commonly use an electronic leak detection tool.

If someone knows how a hair dryer can be used for diagnosing refrigerant leaks (other than melting ice to see the coils), then please post it here so I can read it.

Edit: If the fridge cools well and heavy frost takes several days or weeks to accumulate on the coil, then this could possibly be due to a failed electric defrost coil. These can be checked with an ohm meter and are typically not too difficult to replace.

Edit 2: It appears the SMEG FB30 is not equipped with an electric defrost coil and it merely shuts of the compressor to melt accumulated frost, so my comment above is not applicable to your unit.

  • Thanks, I feel ripped off now :) One more thing which I did not make clear: the "engineer" was blowing at the back of the fridge from the inside, not from the outside. Does it change anything? – quant_dev Sep 4 '15 at 21:21
  • That is as expected. The evaporator coil in a frostless fridge/freezer is usually inside the ice box at the back behind a cover. It sounds like he was thawing an iced up coil. If so, then the coil will probably ice up again in a period of hours, days, or weeks depending on what is wrong. – user39367 Sep 5 '15 at 1:33
  • The engineer's report said "Appliance has a detached wet-wall in bottom left corner. Internal gas leak. Unrepairable." What is a wet-wall? – quant_dev Sep 7 '15 at 9:29
  • This is a little outside my experience. As far as I can tell, a "wet wall" fridge has the evaporator connected to the back of the rear wall of the fridge, such that no circulating fan is required. The rear wall gets cold enough to collect frost which melts into water droplets during the defrost cycle, and visible droplets run down the back of the fridge to the drain (hence the rear wall is called "wet"). I have never worked on one of these. Here is link to a set of videos from Hotpoint on their UK fridges: hotpointservice.co.uk/appliances/fridge-freezers/how-to-videos – user39367 Sep 7 '15 at 20:26
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    Lastly, I found a forum online where a person describes how certain expensive wet wall fridges appear to have an unexpectedly short life due to the solder joints failing and the refrigerant leaking. Here is a link to one of these discussions: navitron.org.uk/forum/index.php?topic=11384.0 – user39367 Sep 7 '15 at 22:27

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