I've been using 3155s for over 7 years without issue. I've only ever had issues with 1 unit and the controller was swapped for a new one @ the place of purchase. Unit would freak out, even plugged into a surge protection circuit.
Replaced and problem went away.
I have 3 of these units and all are reliable as all get out. I keep a spare or 2 pumps around just in case. I got 5 years from a pump before deciding to replace it due to some noise, but it kept working right up until it was replaced.
In 7 years on 3 units I've only replaced 1 pump so far.
I do NOT use Kalk in my ATO - only RO, and never let my pumps run dry.
I installed a relay circuit to protect my pumps becoming dry.
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