However, another difference is the location of the Backwash Flow Control Plug ( 25F ) is on the right hand side ( looking from the front ) on the 155 and has been moved to the left side on the 255.Applying this, the numbers encoded in your example would be. Note: The Brine Control and the Backwash Flow Control plugs are identical in size on both the 155 and the 255.

They are about the size of a dime on the older model 155. The Series 155 was replaced by the Series 255 late 1995 ( early 1996 ).Īn easy way to tell the difference is, the brine control ( salt dial ) is located on the front ( just beneath the timer housing ) on the 155 and it has been relocated to the right side ( looking from the front ) on the 255.Īnother noticeable difference is the Injector Cap, and Injector Screen/Cap are the size of a quarter on the newer 255. The Models 155 ( pre-1996 ) and 255 ( after 1995 ) were not labeled in the past ( Until around year 2000, the 255 started being labeled ) NOTE: Autotrol valves before year 2000, the only 'MODEL' information is found on the Model 163 and 168,Īnd that is the actual number you will find STAMPED in Ink on the Valve Body somewhere ( usually the front under the timer ). ** 87 = year 1987, and per-1980 models may have only 1 digit and would be the year made in the 1970s.

** Made the 125th day of the year, always the first 3 digits. Very Old units that were made with grayish green plastic, will use Black Numbers. Models that use Black Plastic, will have White Numbers. Older models will have a DATE CODE that is Stamped in INK on the Valve Body ( can be front, side, or back ) and Timer Assemblies ( usually on the back side ). Older Models with No Silver label ( mostly pre-2001 ) Such as this October ( 10 ) from 7th day ( 07 ) and 2013 ( 13 ). SOME 460TC timer assembly labels have month then day then year.

This is found on a silver label on back of Valve Body and some Timer Assemblies.

Removing the 155 or 255 Upper Valve Body Module.

Repair Sears, North Star, GE SmartWater.

Sears,North Star, Whirlpool, GE Smartwater, Mortons.

Reading milwaukee date code