What actually triggers the Add Water error on Ninja coffee makers?

i had a ninja that did this and i fixed it by hitting it. Not even joking, smacked the side of it and the error code cleared. Brewed for another 1.5 years after that
 
definately gonna try that start button trick. Mine only does it once every few weeks but i just refill it even though its already full
 
Worked in small appliance repair for about 6 years before I switched careers. Ninja brewers fail in very specific ways. The Add Water error is very common and scale accounts for 70% of the time. 20% of the time it's the reservoir switch or cracked tank and only 10% of the time is the brew pump 70% of the time people assume the brew pump is the issue. If a person uses paper filters that are cheap or grounds get into the brew system (coffee grounds in the water reservoir) then there can be a partial blockage in the outlet. Always descale and clean the machine before replacing any components.
 
Worked in small appliance repair for about 6 years before I switched careers. Ninja brewers fail in very specific ways. The Add Water error is very common and scale accounts for 70% of the time. 20% of the time it's the reservoir switch or cracked tank and only 10% of the time is…

do you have a rough number on how many descaling cycles its worth trying before calling it? like is 2 the limit or have you seen 4-5 finally break through?