Pentair Autotrol 255 User Manual (English)

Brenda FloresSep 9, 2025

What to do if my Pentair 760 controller has no water flow display when water is flowing?

D
Dawn HughesSep 9, 2025
If your Pentair 760 controller shows no water flow when water is flowing, first check if the bypass valve is in the bypass position and shift it to the non-bypass position. Also, the meter probe might be disconnected or not fully connected to the meter housing; fully insert the probe into the meter housing. Finally, restricted meter turbine rotation due to foreign matter in the meter could be the issue; remove the meter housing, free up the turbine, and flush with clean water. The turbine should spin freely; if not, replace the meter.

Brand	Pentair
Model	Autotrol 255
Category	Control Unit
Language	English

Brand

Pentair

Model

Autotrol 255

Generalities

Scope of the documentation

Details the purpose and scope of the manual, including user requirements.

Release management

Tracks document revisions, dates, authors, and publication status.

Manufacturer identifier, product

Provides manufacturer details and the specific product model number.

Intended use

Specifies the product's intended applications and purpose for water treatment.

Abbreviations used

Lists common abbreviations and their meanings used throughout the manual.

Norms and Certificates

Lists applicable directives, standards, and available product certifications.

Procedure for technical support

Outlines the steps for requesting technical assistance and problem resolution.

Copyright and Liability

States copyright information and details limitations of manufacturer liability.

Scan & Service application

Describes a mobile application for accessing product information and service.

Safety

Safety pictograms definition

Explains the meaning of various safety symbols used in the manual.

Serial label location

Shows the location of the product's serial label for identification.

Hazards and Personnel Requirements

Details general hazards, material safety, and personnel qualifications for operation.

Hygiene and Sanitization

Covers sanitary issues, hygiene measures, and disinfection procedures.

Description

Technical specifications

Lists detailed technical specifications and ratings of the valve system.

Valve connections and electrical

Details thread types for valve connections and electrical requirements.

Performance flow rate characteristics

Graph showing flow rate vs. pressure drop for single valve operation.

Outline drawing

Illustrates the physical dimensions and layout of the valve.

Description and components location

Identifies and locates key components of the valve assembly.

Options available on the valve

Lists optional features and kits for the valve system.

Auxiliary Microswitch Kit Installation

Details installation of microswitch kits for electrical signaling.

Top plate mount microswitch

Explains the installation of a top plate mounted microswitch.

System regeneration cycle (8-cycles operation)

Describes the sequence of operations in an 8-cycle regeneration process.

Regeneration cycle diagrams

Illustrates water flow during different regeneration cycles.

Regeneration Sequence for Twin and Lockout Systems

Explains regeneration sequences for twin and lockout configurations.

Twin alternating systems

Details the regeneration process for twin alternating systems.

Twin parallel systems

Explains regeneration sequence for twin parallel systems (Refill off).

Twin parallel system refill options

Details twin parallel system regeneration with refill first option enabled.

Lockout "L" systems

Describes regeneration sequence for lockout systems.

System sizing

Recommendations

Provides general recommendations for system sizing.

Injector/DLFC/Refill flow controler-Valve configuration

Table mapping vessel size to valve components and flow controls.

Cycle time calculation

Explains automatic cycle time calculation by the controller.

Injector flow rates

Graphs showing injector flow rates vs. inlet pressure.

Injector flow rate charts

Flow rate charts for various injector types (J, K, L).

Resin exchange capacity (standard efficiency)

Table of resin capacity based on salt dosage for standard efficiency.

Resin exchange capacity (high efficiency)

Table of resin capacity based on salt dosage for high efficiency.

Installation

Safety notices for installation

Key safety warnings and requirements for installation personnel.

Installation environment

Guidelines for suitable installation locations and environmental conditions.

Mechanical installation

Mechanical installation guidelines and precautions for proper setup.

Outdoor Locations considerations

Specific considerations for installing the unit in outdoor environments.

Integration constraints

Required conditions for integrating the system into plumbing.

Block diagram and configuration example

Illustrates system layout and component connections.

Simplex and Twin systems configurations

Illustrates system configurations for simplex and twin parallel/alternating setups.

Valve connection to piping

Instructions for connecting the valve to the piping system.

Top-mounted valve installation

Guidelines for mounting and connecting the valve to the tank.

Installation compensation and lubrication

Proper compensation and lubrication guidelines for valve installation.

Electrical connections

Details electrical connections for the controller and sensors.

Interconnected systems and Twin wiring

Wiring diagrams for multi-simplex and twin parallel/alternating systems.

Bypassing instructions

Explains the function and installation of bypass valves.

Drain line connection

Instructions for connecting the drain line with air gap requirements.

Overflow line connection

Details how to connect the overflow line to the drain.

Brine line connection

Instructions for connecting the brine line to the valve.

Programming

Display overview

Explains the different elements and indicators on the controller display.

Display indicators

Detailed explanation of display elements like units and symbols.

Controller commands

Describes the function of each button on the controller interface.

Basic programming overview

Overview of the basic programming menu and general notes.

Basic programming 742/762 controllers

Step-by-step guide for basic programming on 742/762 controllers.

Regeneration time and day settings (742/762)

Setting regeneration time, days override, and day of week for 742/762.

Salt amount and capacity settings (742/762)

Setting salt amount, system capacity, and hardness for 742/762.

Basic programming 764 controller

Step-by-step guide for basic programming on 764 controller.

Time, day, and regeneration settings (764)

Setting time, day, regeneration time, and days override for 764 controller.

Salt, capacity, and hardness settings (764)

Setting salt amount, system capacity, and hardness for 764 controller.

Advanced programming overview

Introduction to advanced programming for 8-cycle softener systems.

Advanced parameter details

Details parameters P9-P12: units, clock mode, service interval, remote switch delay.

Advanced parameter details (cont.)

Details parameters P13-Pd: chlorine options, refill/draw rates, reserve, regeneration mode.

Cycle time programming

How to program specific cycle times for the softener.

Diagnostic codes and interpretation

Information on accessing and interpreting diagnostic codes.

Resetting the controller

Procedure for resetting the controller to factory default settings.

Commissioning

Water filling, draining and watertightness inspection

Procedures for filling, draining, and checking for leaks.

System startup and initial regeneration

Steps to initiate the system and start the first regeneration.

Brine tank initial fill and refill cycle

Instructions for initial brine tank fill and priming the refill cycle.

Drawing water from brine tank and tips

Procedure to draw water from brine tank and additional commissioning tips.

Sanitization and System disinfection

Procedures for sanitizing and disinfecting the water softener system.

Hypochlorite and Electro chlorination disinfection

Details using hypochlorite and electro chlorination for disinfection.

Operation

Recommendations for operation

Recommendations for optimal operation and salt usage.

Manual regeneration procedures

Instructions for initiating manual regeneration cycles and advancing/canceling.

Automatic regeneration modes (twin system)

Automatic regeneration modes for twin systems (764 only).

Parallel systems regeneration modes

Explains regeneration modes for parallel systems (P16=0, P16=1).

Parallel systems regeneration modes (cont.)

Describes P16=2 and P16=3 regeneration modes for parallel systems.

Maintenance

General system inspection

Annual inspection checklist for the system's components.

Water quality and mechanical checks

Checking water quality and performing mechanical component checks.

Regeneration test

Performing tests to verify regeneration function.

Recommended maintenance plan

Schedule for maintenance of various components over 5 years.

Recommendations on Parts, Lubricants, and Maintenance

Advice on spare parts, lubricants, and general maintenance instructions.

Cleaning and maintenance procedures

First steps and detailed procedures for cleaning various components.

Troubleshooting

ERR 1-3: Controller and camshaft errors

Troubleshooting for controller power, frequency, and camshaft rotation errors.

ERR 4 and brine tank issues

Troubleshooting camshaft position errors and brine tank overflow.

Water flow and regeneration issues

Diagnosing water flow problems and dripping water after regeneration.

Hard water, brine draw, and timing issues

Resolving hard water leaks, brine draw failures, and incorrect timing.

Conditioned water, flow rates, and overflow issues

Troubleshooting no conditioned water, abnormal flow rates, and brine tank overflow.

Spare parts

Valve parts list

Illustrated list of valve components and their part numbers.

Valve Parts List Details

Detailed listing of valve assembly parts and quantities.

Valve Parts List Details (Continued)

Continuation of the detailed valve parts list.

Options and special kits

Lists controller options and special kits available for the system.

Meter adapter parts

Parts list for meter adapter kits.

Piping boss and manifold parts

Lists various piping boss and manifold components.

Bypass and connection parts

Lists parts for bypass body and various connection adapters.

Interconnecting kit and connection parts

Lists parts for interconnecting kits and connections.

Valve installation kits

Lists components included in valve installation kits.

Disposal

Disposal guidelines

Guidelines for environmentally responsible disposal of the device.

Pentair Autotrol 255 User Manual

Table of Contents

Questions and Answers:

Pentair Autotrol 255 Specifications

Summary