Why does levelling the RV affect the life of the fridge?
In absorption (ammonia) RV refrigerators the evaporator tubing is built with a slope so that the liquid flows by gravity. If the vehicle is stationary and the fridge is run out of level, liquid ammonia collects in sections of the evaporator tube and cooling stops. Compressor fridges have no such mechanism; their tolerances are markedly wider.
An absorption cooling circuit has no pump; the flow relies entirely on gravity. That is why the evaporator tubing is produced at the factory with a specific slope. When the RV is out of level that slope is lost, liquid ammonia collects in sections of the tube and circulation in the circuit is interrupted. The result is first weakened cooling and, if repeated continuously, permanent damage to the cooling unit.
For this reason the manuals of absorption fridge manufacturers require the fridge to be run level after the vehicle is parked. The tolerance value varies by model; take the value in your own appliance's manual as the reference - it would not be correct to give a universal angle figure.
In practice two points matter:
- While the vehicle is moving, the sloshing keeps the flow going, so the slope is not a problem; the risk arises while parked.
- The cooling unit contains ammonia under pressure; if you smell ammonia, switch the fridge off and call service, do not open the circuit.
Because a system such as the KTS200 does the post-parking levelling with a single button and to 0,025 degree precision, in RVs with an absorption fridge levelling is not a comfort matter but a question of equipment life.
The full topic: RV automatic levelling guide