Try cleaning the cell in the recommended acid solution. DO NOT go stronger. Immerse the cell in the solution until the bubbling stops, rinse, re-install.

Error "94" can also mean a cut in the cord running to the cell or it may be unplugged. You might want to carefully examine that.

If the unit is only a few months old, Polaris MIGHT help. The warranty is to the original owner, but they are a good company and MIGHT send a warranty tech.