Norcold 1200 ammonia top up?

DrewE wrote:
You can't just "top off" the ammonia, no. It's actually a mixture of a few different things in the cooling unit: water, ammonia, hydrogen gas, and a corrosion inhibitor (which isn't directly involved in the cooling cycle). The whole works is under rather high pressure.

It's doubtful that just some of the refrigerant has escaped; more likely in my opinion is some other sort of problem, maybe debris blocking the ventilation airflow, or some control problem, or the door not sealing properly, or frost and ice buildup, or the cooling unit getting clogged (which isn't really repairable).

If you had an ammonia leak and were around at the time, you'd be well aware of it! You could usually also see the chromate residue left behind.

Sealed unit.....ammonia, hydrogen, sodium chromate and water under 300 psi
Sodium chromate will crystallize and plate out which can obstruct/block coolant flow causing more overheating which accumulates and slowly results in lack of cooling
(Sodium chromate is the rust inhibitor and will leave a yellowish residue when cooling unit leaks)

Norcold 1200 NEEDS external fans to more sufficient airflow across the cooling unit in order for enough heat to be removed so cooling can be accomplished.
So you have any external fans?
Are they coming on?

Items required for cooling effect
Proper heat source
Sufficient Airflow
Proper clearances/Baffles if needed
No Dead Air Spaces
Functional controls