'$37$*0.82-0403Gas'JSFE %JSFDU 7FOU4UBJOMFTT 4UFFM #PJMFST$,4FSJFTo$,$,$POUSPM Manual$POUSPM"EKVTUNFOUBOE0QFSBUJPO Instructions5IJTJOTUSVDUJPONBOVBMBQQMJFTPOMZUP3#*GJSNXBSFWFSTJPOY POWFSTJPOYDPOUSPMCPBSETAlso read and follow:'MFY$PSF$,4FSJFT(BT#PJMFS*OTUBMMBUJPOBOE0QFSBUJOH*OTUSVDUJPO.BOVBM)This manual is intended only for use by a qualified heating installer/technician. Read and follow this manual, all supplementsand related instructional information provided with the boiler. Install, start and service the boiler only in the sequence andmethods given in these instructions. Failure to do so can result in severe personal injury, death or substantial property damage.Do not use the boiler during construction. Construction dust and particulate, particularly drywall dust, will cause contaminationof the burner, resulting in possible severe personal injury, death or substantial property damage. The boiler can only be operated witha dust-free air supply. Follow the instruction manual procedures to duct air to the boiler air intake. If the boiler has been contaminatedby operation with contaminated air, follow the instruction manual guidelines to clean, repair or replace the boiler if necessary.Affix these instructions near to the boiler. Instruct the building owner to retain the instructions for future use by a qualifiedservice technician, and to follow all guidelines in the User’s Information Manual.Copyright 201 Mestek, Inc.

Introduction

Features & Specifications

Specifications

Components & Accessories

SETUP & OPERATION

PERATION

Heating Control Methods

I NPUT P RIORITIES

ONTROL T1-T2

Domestic Hot Water Methods

S ) EMPLOYING H-N ET

EATING ONLY USING A

EADER S ENSOR I NPUT

USING AN A QUASTAT

K TANK SENSOR

DHW M AXIMUM R UNTIME

Base Loading, Relay Control

Using the 4-20 mA input (OPTIONAL)

S ETPOINT P RIORITIES

Local Pump Options

Combustion Air Damper

Sensors

Diagnostics

Communications

Limited Flow Boiler Control Options

FlexCore Multi Heat Exchangers

H EAT E XCHANGER WIRING

HeatNet Online

Wiring Connections

Home Screen Navigation

Home Screen

Home Screen Messages

S ETPOINT S OURCE M ESSAGES

Calibration

C ALIBRATION WITH M ULTIPLE H EAT E XCHANGERS

Log Entry

CONTROL SETTINGS MENU

CONTROL SETTINGS MENU— PAGE 1

CONTROL SETTINGS MENU— PAGE 2

CONTROL SETTINGS MENU — PAGE 3

CONTROL SETTINGS MENU — PAGE 4

MODBUS Communications

Worksheet

Type II Thermistor Resistance/Temperature Table

RBI FlexCore CK 850 Control Manual

FlexCore CK 1000

FlexCore CK 1500

FlexCore CK 2000

FlexCore CK 2500

FlexCore CK 3000

FlexCore CK 3500

FlexCore CK 4000

FlexCore CK 4500

FlexCore CK 5000

FlexCore CK 6000

FlexCore CK 850