Aerco BMK 2500 - User Manual

Questions and Answers

E
Erin VegaSep 8, 2025
What to do if Aerco BMK 2500 shows Residual Flame?
- B
  Brenda FoleySep 8, 2025
  Replace Flame Detector. Check open/close indicator window of Safety Shut-Off Valve (SSOV) and ensure that the SSOV is fully closed. If not fully closed, replace the valve and or actuator. Close the 2” Gas Shut-Off Valve downstream of SSOV (Figure 2-7). Install a manometer or gauge at the leak detection port between the SSOV and Gas Shut Off Valve. If a gas pressure reading is observed replace the SSOV Valve and/or Actuator.
D
Darlene RamirezAug 25, 2025
What to do if Aerco BMK 2500 displays Flame Loss During Ignition?
- S
  Samuel WilliamsonAug 25, 2025
  If your Aerco Boiler is showing a 'FLAME LOSS DURING IGN' error, remove and inspect the flame detector for signs of wear and replace if necessary. Close the internal gas valve in the unit and install and arc a spark igniter outside the unit. If there is no spark, check for 120VAC at the primary side to the ignition transformer during the ignition cycle.
U
ukingAug 25, 2025
What does Delayed Interlock Open mean on Aerco Boiler?
- S
  Shane GillAug 26, 2025
  If your Aerco Boiler displays a 'DELAYED INTERLOCK OPEN' error, check to ensure the jumper is properly installed across the delayed interlock terminals in the I/O Box. If there are two external wires on these terminals, check to see if an end switch for a proving device is tied to these interlocks. Ensure that the device and/or its end switch is functional. A jumper may be temporarily installed to test the interlock.
B
Brian WagnerSep 18, 2025
How to troubleshoot low gas pressure on Aerco BMK 2500?
- B
  Brandy GarciaSep 18, 2025
  If your Aerco Boiler displays a low gas pressure error, measure the gas pressure upstream of the SSOV Actuator(s) with the unit firing. Also, measure gas pressure at the Low Gas Pressure switch and measure continuity across the switch.
F
Frederick WilsonSep 13, 2025
What to do if Aerco BMK 2500 Boiler shows PRG SWTCH CLOSED DURING IGNITION?
- C
  Chelsea HunterSep 13, 2025
  If your Aerco Boiler is showing a PRG SWTCH CLOSED DURING IGNITION error, the air/fuel valve may have rotated open to purge but did not rotate to the ignition position. Check the air/fuel valve calibration. If calibration is okay, the problem may be in the air/fuel valve or the control box. If the air/fuel valve does rotate to the ignition position, check the purge switch for continuity between the N.O. and COM terminals. Also, check DS1 & DS2 LEDs on the Power Supply Board and the “Heartbeat” LED DS1 on the IGST Board.
R
Robert ClarkSep 4, 2025
How do I troubleshoot a Remote Setpt Signal Fault on my Aerco BMK 2500 Boiler?
- T
  Tiffany GeorgeSep 4, 2025
  If your Aerco Boiler is displaying a 'REMOTE SETPT SIGNAL FAULT', check the I/O Box to ensure the signal is hooked up. If not installed, hook it up. If installed, check the polarity. Measure the signal level and check the continuity of wiring between the source and the unit. If it is a 4 to 20 mA signal, check the signal at the source to ensure it is isolated. Check the DIP switch on the PMC board to ensure it is set correctly for the type of signal being sent. Check the control signal type set in the Configuration Menu.
M
Miguel UnderwoodSep 4, 2025
How to resolve Line Voltage Out of Phase error on Aerco Boiler?
- A
  andreadanielSep 4, 2025
  If your Aerco Boiler is showing a 'LINE VOLTAGE OUT OF PHASE' error, check the hot and neutral wires in the AC Power Box to ensure they are not reversed. Also, check the transformer wiring in the AC Power Box against the power box transformer wiring diagram to ensure it is wired correctly.
S
steven79Sep 23, 2025
What causes residual flame in Aerco BMK 2500?
- V
  Vanessa AndradeSep 23, 2025
  If your Aerco Boiler shows a residual flame, replace the flame detector. Check the open/close indicator window of the safety shut-off valve and ensure that the SSOV is fully closed. Close the 2” Gas Shut-Off Valve downstream of SSOV. Install a manometer or gauge at the leak detection port between the SSOV and Gas Shut Off Valve. If a gas pressure reading is observed replace the SSOV Valve and/or Actuator.
A
Adam MackAug 29, 2025
What causes High Water Temp Switch Open error in Aerco Boiler?
- P
  phamheatherAug 29, 2025
  If your Aerco Boiler displays a 'HIGH WATER TEMP SWITCH OPEN' error, test the water temperature switch to ensure it trips at its actual water temperature setting. Check the PID settings against the default settings and reset them if necessary, after recording the current readings. Measure the resistance of the shell sensor and BTU sensor at a known water temperature using the resistance charts. If the unit is in Manual Mode, switch to Auto Mode. Ensure that the temperature switch setpoint is higher than the unit’s setpoint. If the system is a variable flow system, monitor system flow changes to ensure that the rate of flow change is not faster than what the units can respond to.
N
Nathan SchneiderAug 30, 2025
How do I troubleshoot an SSOV Switch Open error on my Aerco BMK 2500?
- V
  Victor JimenezAug 30, 2025
  If your Aerco Boiler is showing a 'SSOV SWITCH OPEN' error, observe the Safety Shut-Off Valve (SSOV) through the indicator on the valve actuator to ensure that the valve is fully closing, not partially. If the SSOV never closes, it may be continuously powered; in this case, close the gas supply and remove power from the unit, then refer the fault to qualified service personnel. Remove the electrical cover from the SSOV and check switch continuity; if the switch does not show continuity with the gas valve closed, adjust or replace the switch or actuator. Finally, ensure that the SSOV Proof of Closure switch is correctly wired.

Summary

Chapter 1: Safety Precautions

Warnings and Cautions

General warnings and cautions for safe operation and installation of the boiler.

Emergency Shutdown

Procedure to shut down the boiler in case of overheating or gas supply failure.

Chapter 2: Installation

Site Preparation

Requirements for the installation site, including power and gas connections.

Installation Clearances

Gas Supply Piping

Requirements and procedures for installing natural gas supply piping.

External Gas Supply Regulator

AC Electrical Power Wiring

Instructions for connecting AC power wiring to the unit.

Electrical Power Requirements

Chapter 3: Operation

Control Panel Description

Control Panel Menus

Description of the menu structure for setting up and configuring the unit.

Menu Processing Procedure

Setup Menu

Permits entry of password, date, time, and temperature units.

Configuration Menu

Allows adjustment of internal setpoint and other configuration settings.

Combustion Cal Menu

Menu for varying blower speed to optimize combustion efficiency.

BST (Boiler Sequencing Technology) Menu

Start Sequence

Sequence of events from unit startup to flame proven.

Chapter 4: Initial Start-Up

Initial Start-Up Requirements

Prerequisites for initial unit start-up, including installation and testing.

Tools and Instrumentation for Combustion Calibration

Necessary tools and instrumentation for performing combustion calibration.

Required Tools & Instrumentation

List of essential tools and instruments for combustion calibration.

Installing Gas Supply Manometer

Accessing the Analyzer Probe Port

Natural Gas Combustion Calibration

Procedure for calibrating the boiler's combustion for natural gas.

Over-Temperature Limit Switches

Description of the three types of over-temperature limit switches.

Digital Alarm Switch Checks and Adjustments

Chapter 5: Mode of Operation

Indoor;Outdoor Reset Mode

Mode based on outside air temperatures to adjust supply header temperature.

Constant Setpoint Mode

Mode used for fixed header temperature applications.

Setting the Setpoint

Remote Setpoint Modes

Controlling the unit's setpoint remotely via EMS or BAS.

Direct Drive Modes

Changing air/fuel valve position via a remote signal from EMS or BAS.

AERCO Control System (ACS)

Combination Control System (CCS)

Chapter 6: Safety Device Testing

Testing of Safety Devices

Ensuring control system and safety devices operate properly through periodic tests.

Low Gas Pressure Fault Test

Procedure to simulate and test the low gas pressure fault.

High Gas Pressure Test

Procedure to simulate and test the high gas pressure fault.

Low Water Level Fault Test

Procedure to simulate and test the low water level fault condition.

Water Temperature Fault Test

Procedure to simulate and test the high water temperature fault.

Interlock Tests

Tests for Remote and Delayed Interlock circuits.

Remote Interlock Test

Delayed Interlock Test

Flame Fault Tests

Procedure to simulate flame faults during ignition or operation.

Air Flow Fault Tests

Tests for Blower Proof Switch and Blocked Inlet Switch operation.

Blower Proof Switch Test

Procedure to test the blower proof switch functionality.

Blocked Inlet Switch Test

Procedure to test the blocked inlet switch functionality.

SSOV Proof of Closure Switch

Checking the proof of closure switch circuit for the SSOV.

Purge Switch Open During Purge

Testing the purge switch when it opens during the purge cycle.

Ignition Switch Open During Ignition

Testing the ignition switch when it opens during ignition.

Safety Pressure Relief Valve Test

Chapter 7: Maintenance

Maintenance Schedule

Routine maintenance procedures and schedules for optimal boiler performance.

Igniter-Injector

Flame Detector

O2 Sensor

Safety Device Testing

Performing systematic tests of operating and safety devices.

Burner Assembly Inspection

Procedures for inspecting and maintaining the burner assembly.

Condensate Drain Trap

Air Filter Cleaning & Replacement

Chapter 8: Troubleshooting Guide

Introduction

Guide for isolating causes of faults in Benchmark boilers.

Additional Faults Without Specific Fault Messages

Chapter 9: RS-232 Communication

RS-232 Communication Setup

Menu Processing Utilizing RS-232 Communication

Data Logging

Fault Log

Operation Time Log

Sensor Log

Chapter 10: Boiler Sequencing Technology

Introduction

AERCO BST Quick Start Chart

BST Implementation Instruction

Detailed instructions for implementing various BST options.

Option 1 - Constant Setpoint with DIRECT Wired Header Sensor

Option 2 - Constant Setpoint with MODBUS Wired Header Sensor

Option 3 - Outdoor Reset with DIRECT WIRED Header Sensor AND DIRECT WIRED Outdoor Sensor

Option 4 - Outdoor Reset with MODBUS Header Sensor AND MODBUS Outdoor Sensor

Option 5 - Remote Setpoint with DIRECT WIRED Header Sensor AND 4-20 ma Setpoint Drive

Option 6 - Remote Setpoint with DIRECT WIRED Header Sensor AND MODBUS Setpoint Drive

Option 7 - Remote Setpoint with MODBUS Header Sensor AND 4-20 ma Setpoint Drive

Option 8 - Remote Setpoint with MODBUS Header Sensor AND MODBUS Setpoint Drive

Appendix A: Boiler Menu Item Descriptions

Configuration Menu

Appendix B: Startup, Status & Display Messages

Table B-2: Fault Messages

List and description of fault messages that may be displayed.

Appendix D: Boiler Default Settings

Appendix E: Recommended Periodic Testing

Appendix F: Indoor;Outdoor Reset Ratio Charts

Appendix J: C-More Wiring Diagrams

Summary

Chapter 1: Safety Precautions

Warnings and Cautions

General warnings and cautions for safe operation and installation of the boiler.

Emergency Shutdown

Procedure to shut down the boiler in case of overheating or gas supply failure.

Chapter 2: Installation

Site Preparation

Requirements for the installation site, including power and gas connections.

Installation Clearances

Gas Supply Piping

Requirements and procedures for installing natural gas supply piping.

External Gas Supply Regulator

AC Electrical Power Wiring

Instructions for connecting AC power wiring to the unit.

Electrical Power Requirements

Chapter 3: Operation

Control Panel Description

Control Panel Menus

Description of the menu structure for setting up and configuring the unit.

Menu Processing Procedure

Setup Menu

Permits entry of password, date, time, and temperature units.

Configuration Menu

Allows adjustment of internal setpoint and other configuration settings.

Combustion Cal Menu

Menu for varying blower speed to optimize combustion efficiency.

BST (Boiler Sequencing Technology) Menu

Start Sequence

Sequence of events from unit startup to flame proven.

Chapter 4: Initial Start-Up

Initial Start-Up Requirements

Prerequisites for initial unit start-up, including installation and testing.

Tools and Instrumentation for Combustion Calibration

Necessary tools and instrumentation for performing combustion calibration.

Required Tools & Instrumentation

List of essential tools and instruments for combustion calibration.

Installing Gas Supply Manometer

Accessing the Analyzer Probe Port

Natural Gas Combustion Calibration

Procedure for calibrating the boiler's combustion for natural gas.

Over-Temperature Limit Switches

Description of the three types of over-temperature limit switches.

Digital Alarm Switch Checks and Adjustments

Chapter 5: Mode of Operation

Indoor;Outdoor Reset Mode

Mode based on outside air temperatures to adjust supply header temperature.

Constant Setpoint Mode

Mode used for fixed header temperature applications.

Setting the Setpoint

Remote Setpoint Modes

Controlling the unit's setpoint remotely via EMS or BAS.

Direct Drive Modes

Changing air/fuel valve position via a remote signal from EMS or BAS.

AERCO Control System (ACS)

Combination Control System (CCS)

Chapter 6: Safety Device Testing

Testing of Safety Devices

Ensuring control system and safety devices operate properly through periodic tests.

Low Gas Pressure Fault Test

Procedure to simulate and test the low gas pressure fault.

High Gas Pressure Test

Procedure to simulate and test the high gas pressure fault.

Low Water Level Fault Test

Procedure to simulate and test the low water level fault condition.

Water Temperature Fault Test

Procedure to simulate and test the high water temperature fault.

Interlock Tests

Tests for Remote and Delayed Interlock circuits.

Remote Interlock Test

Delayed Interlock Test

Flame Fault Tests

Procedure to simulate flame faults during ignition or operation.

Air Flow Fault Tests

Tests for Blower Proof Switch and Blocked Inlet Switch operation.

Blower Proof Switch Test

Procedure to test the blower proof switch functionality.

Blocked Inlet Switch Test

Procedure to test the blocked inlet switch functionality.

SSOV Proof of Closure Switch

Checking the proof of closure switch circuit for the SSOV.

Purge Switch Open During Purge

Testing the purge switch when it opens during the purge cycle.

Ignition Switch Open During Ignition

Testing the ignition switch when it opens during ignition.

Safety Pressure Relief Valve Test

Chapter 7: Maintenance

Maintenance Schedule

Routine maintenance procedures and schedules for optimal boiler performance.

Igniter-Injector

Flame Detector

O2 Sensor

Safety Device Testing

Performing systematic tests of operating and safety devices.

Burner Assembly Inspection

Procedures for inspecting and maintaining the burner assembly.

Condensate Drain Trap

Air Filter Cleaning & Replacement

Chapter 8: Troubleshooting Guide

Introduction

Guide for isolating causes of faults in Benchmark boilers.

Additional Faults Without Specific Fault Messages

Chapter 9: RS-232 Communication

RS-232 Communication Setup

Menu Processing Utilizing RS-232 Communication

Data Logging

Fault Log

Operation Time Log

Sensor Log

Chapter 10: Boiler Sequencing Technology

Introduction

AERCO BST Quick Start Chart

BST Implementation Instruction

Detailed instructions for implementing various BST options.

Option 1 - Constant Setpoint with DIRECT Wired Header Sensor

Option 2 - Constant Setpoint with MODBUS Wired Header Sensor

Option 3 - Outdoor Reset with DIRECT WIRED Header Sensor AND DIRECT WIRED Outdoor Sensor

Option 4 - Outdoor Reset with MODBUS Header Sensor AND MODBUS Outdoor Sensor

Option 5 - Remote Setpoint with DIRECT WIRED Header Sensor AND 4-20 ma Setpoint Drive

Option 6 - Remote Setpoint with DIRECT WIRED Header Sensor AND MODBUS Setpoint Drive

Option 7 - Remote Setpoint with MODBUS Header Sensor AND 4-20 ma Setpoint Drive

Option 8 - Remote Setpoint with MODBUS Header Sensor AND MODBUS Setpoint Drive

Appendix A: Boiler Menu Item Descriptions

Configuration Menu

Appendix B: Startup, Status & Display Messages

Table B-2: Fault Messages

List and description of fault messages that may be displayed.

Appendix D: Boiler Default Settings

Appendix E: Recommended Periodic Testing

Appendix F: Indoor;Outdoor Reset Ratio Charts

Appendix J: C-More Wiring Diagrams

Aerco BMK 2500 Specifications

General

Brand	Aerco
Model	BMK 2500
Category	Boiler
Language	English

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Aerco BMK 2500 - User Manual

Table of Contents

Questions and Answers

Summary

Chapter 1: Safety Precautions

Warnings and Cautions

Emergency Shutdown

Chapter 2: Installation

Site Preparation

Installation Clearances

Gas Supply Piping

External Gas Supply Regulator

AC Electrical Power Wiring

Electrical Power Requirements

Chapter 3: Operation

Control Panel Description

Control Panel Menus

Menu Processing Procedure

Setup Menu

Configuration Menu

Combustion Cal Menu

BST (Boiler Sequencing Technology) Menu

Start Sequence

Chapter 4: Initial Start-Up

Initial Start-Up Requirements

Tools and Instrumentation for Combustion Calibration

Required Tools & Instrumentation

Installing Gas Supply Manometer

Accessing the Analyzer Probe Port

Natural Gas Combustion Calibration

Over-Temperature Limit Switches

Digital Alarm Switch Checks and Adjustments

Chapter 5: Mode of Operation

Indoor;Outdoor Reset Mode

Constant Setpoint Mode

Setting the Setpoint

Remote Setpoint Modes

Direct Drive Modes

AERCO Control System (ACS)

Combination Control System (CCS)

Chapter 6: Safety Device Testing

Testing of Safety Devices

Low Gas Pressure Fault Test

High Gas Pressure Test

Low Water Level Fault Test

Water Temperature Fault Test

Interlock Tests

Remote Interlock Test

Delayed Interlock Test

Flame Fault Tests

Air Flow Fault Tests

Blower Proof Switch Test

Blocked Inlet Switch Test

SSOV Proof of Closure Switch

Purge Switch Open During Purge

Ignition Switch Open During Ignition

Safety Pressure Relief Valve Test

Chapter 7: Maintenance

Maintenance Schedule

Igniter-Injector

Flame Detector

O2 Sensor

Safety Device Testing

Burner Assembly Inspection

Condensate Drain Trap

Air Filter Cleaning & Replacement

Chapter 8: Troubleshooting Guide

Introduction

Additional Faults Without Specific Fault Messages

Chapter 9: RS-232 Communication

RS-232 Communication Setup

Menu Processing Utilizing RS-232 Communication

Data Logging

Fault Log

Operation Time Log

Sensor Log

Chapter 10: Boiler Sequencing Technology

Introduction

AERCO BST Quick Start Chart

BST Implementation Instruction