By the time a level alarm sounds, the tank has been trying to tell you for months. The vacuum between the two walls leaks away over years, and the vessel signals it three times on the way down.
Warning one: the fill log
Litres added per week creeps up with no change in how often the lid is opened. A 20 per cent rise on baseline is a phone call to the supplier. A doubling is a plan to move samples. This only works if fills are logged from day one.
Warning two: the outer shell
It should feel like the room. Condensation, a cold patch near the base, frost around the evacuation port: heat is crossing the gap that exists to stop it. The back of a hand on a walk round costs nothing.
Warning three: recovery after opening
A vessel that used to settle within a minute of a rack being pulled, and now vents visibly for longer, has less insulation to fall back on.
When two appear together
Act while the tank is still holding temperature: charge a backup, book the supplier, read the vacuum warranty. The CryoBank Series is listed with a five year vacuum warranty and two years on parts, which is the kind of term worth checking before you need it.
The CryoBank Series pages list warranty and alarm specification per model.
