Wednesday, May 9, 2007

Autotrol 155 or 255 - How to Tell Which You Have

155 Valve Body Diagram

Above is the 155 Valve Body Diagram
Below is the newer 255 Valve Body Diagram
Click on to ENLARGE VIEW

255 Valve Body Diagram

How do I know if I have an Autotrol 155 ( 1550-TC ) or a model 255 Valve?

1. The Series 155 was replaced by the Series 255 late 1995 ( early 1996 ). An 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.

Another noticeable difference is the Injector Cap, and Injector Screen/Cap are the size of a quarter on the newer 255. They are about the size of a dime on the older model 155.

Note: The Brine Control and the Backwash Flow Control plugs are identical in size on both the 155 and the 255. 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.


Anonymous said...

I am renting a apt with a Futurmatic water conditioner and it is set to regenerate every other day but I am alone so do not need that. I want to reset the pins to regenerate once a week on Sat nite--does the Sat pin need to be pushed in or pulled out and the rest of them the opposite--I have used 80# in one week so need to know as no instructions here.

Andrew at said...

If you push the pin IN on the Sat, it will regenerate at 2:30 a.m. to around 4 a.m. Saturday morning. Pull all the other pins OUT. One once a week should be enough for only one person, although I'd need to know the hardness, and iron level, plus the size or capacity of the resin tank to be able verify this "average" setting for you.