Absorption fridges (gas/electric)
These cool with heat. If it cools on one mode but not the other, the cooling unit is fine and you're chasing the bad heat source.
The short version
- Needs to be close to level and needs airflow out the back and roof vent.
- Takes hours to cool down. Don't call it bad after 30 minutes.
- Electric not working: check 120V at the outlet, then the heating element ohms.
- Gas not working: dirty burner, spider webs, bad igniter or flame sensor.
- Yellow powder or ammonia smell = cooling unit leak. That's a replace.
On the job
- Level first: a level on the freezer floor, 3° side to side, 6° front to back max.
- Dollar bill test both gaskets. Frost thickest where the gasket leaks.
- Feel the boiler and absorber from the outside vent. Very hot boiler and no frost on the fins = no circulation (level) or a dying unit.
- Look for yellow powder, ammonia smell, wet boiler insulation. Any of those: do not run it, replace the cooling unit.
- Then the heat source: 11 in WC and a blue flame on gas; 108 to 132 V and element ohms on electric.
Numbers
- 325W heater element: ~44Ω
- Cool-down: 4–8 hours
- Level limit: 3° side to side, 6° front to back
- Cooling unit test: thermistor off, coldest, 3 to 4 h: freezer -5 to -10°F
Shop tip
Feel the back. Boiler area hot but the box warm = cooling unit problem. Boiler cold = heat source problem.
Try it on a service call
Put the lesson to work on a hands-on troubleshooting case.
Keep going on refrigerators
Learn it
- 12V compressor and residential fridges
- Absorption fridge won't run on gas
- Absorption fridge won't run on electric
- Is it the cooling unit?
- Fridge control boards and codes
Prove it
- Fridge won't run on gas
- Fridge is warm after unplugging
- Fridge works on gas, not electric
- Fridge won't cool on anything
- Freezer's fine, fridge is warm