I have a flow error on a k machine with alot of hours on it ,the condo only goes to 12.5 and no higher,I have done all the calibrations and changed the acid pump.and check valves.There is'nt a constent error just on and off.....Please help

balance chambers!!!

Check the flow from your drain. If it has a hard pulse and then a dribble our a couple of pulses and then a dribble you need to change the membrane in your balance chamber. Drain flow should always be steady even pulses of fluid.