ATO Not Topping Off

[crimson0152]

I have an ATO that has been modified to also do automatic water changes. (In fact you had this unit in your shop a few weeks ago.) Its been working fine ever since I got it back from you, but as of yesterday, it stopped topping off. The water evaporates, but no top off. It drains water for the water change, but doesn't pump any salt water back to the tank. What can I check to troubleshoot the problem?

Thanks
Mark

[rvitko]

I would disconnect the added box and try running it as it was intended. The controller can only support 1200mA of load, if at any point both pumps were called on it would force a shut down.