Keystone KSTHW08B - User Manual

Questions and Answers

B
Brandon JonesAug 14, 2025
Why is my Keystone KSTHW08B Air Conditioner not cold enough?
- J
  Jessica TorresAug 14, 2025
  If the air from your Keystone air conditioner doesn't feel cold enough, consider the following: * If the room temperature is below 62°F (17°C), cooling may not occur until the room warms up. * The temperature sensor behind the air filter element might be touching the cold coil. Keep it away from the cold coil. * Try setting the unit to a lower temperature. * Wait for 3 minutes after setting the unit to COOL mode.
W
williamskatieAug 17, 2025
What to do if my Keystone KSTHW08B does not start?
- B
  Bryan ScottAug 17, 2025
  If your Keystone air conditioner isn't starting, there are several potential causes: * The wall plug may be disconnected. Ensure it's firmly pushed into the outlet. * A house fuse might be blown, or a circuit breaker tripped. Replace the fuse with a time delay type or reset the circuit breaker. * The Plug Current Device may have tripped. Press the RESET button. * The power may be off. Turn the power ON.
P
poolejennyAug 20, 2025
Why is my Keystone air conditioner cooling, but the room is too warm with no ice forming?
- N
  nvaldezAug 20, 2025
  If your Keystone air conditioner is running but the room isn't cooling down and there's no ice on the cooling coil, consider these possibilities: * The air filter might be dirty, restricting airflow. Clean the air filter. * The set temperature could be too high. Lower the temperature setting. * Air directional louvers may be positioned improperly. Adjust the louvers for better air distribution. * The front of the unit might be blocked by drapes, blinds, or furniture. Clear any blockage. * Doors, windows, or registers might be open. Close them. * Allow additional time for the unit to remove stored heat from walls, ceiling, floor, and furniture.
W
wlittleAug 25, 2025
Why is my Keystone air conditioner cooling, but the room is too warm and ice is forming?
- A
  Ariel LewisAug 25, 2025
  If your Keystone air conditioner is cooling, but the room is too warm and ice is forming on the cooling coil, here's what might be happening: * The outdoor temperature may be below 64°F (18°C). Set the unit to FAN ONLY mode to defrost the coil. * The air filter may be dirty. Clean the filter and set to FAN ONLY mode to defrost. * The thermostat may be set too cold for night-time cooling. Set to FAN ONLY mode to defrost, then increase the temperature setting.
L
Laura GuerreroAug 27, 2025
What to do if my Keystone air conditioner turns on and off rapidly?
- D
  Diane GordonAug 27, 2025
  If your Keystone air conditioner is turning on and off rapidly, it could be due to: * A dirty air filter restricting airflow. Clean the air filter. * Extremely hot outside temperatures. Increase the FAN speed to circulate air past the cooling coils more frequently.
S
schangAug 30, 2025
Why is my Keystone room air conditioner too cold?
- T
  Terry StanleyAug 30, 2025
  If your Keystone air conditioner is making the room too cold, it might be because the set temperature is too low. Try increasing the set temperature.
D
debbiejamesSep 3, 2025
What to do if my Keystone air conditioner is making noise when cooling?
- M
  Matthew GonzalezSep 3, 2025
  If your Keystone air conditioner is making noise while cooling: * The noise may be due to normal air movement. If it's too loud, try setting the fan to a slower speed. * Window vibration could be the cause, indicating poor installation. Refer to the installation instructions or check with the installer.
R
Robert AllenSep 6, 2025
What to do if water is dripping inside my Keystone air conditioner when it's cooling?
- A
  amanda52Sep 6, 2025
  If water is dripping inside your Keystone air conditioner while it's cooling, it's likely due to improper installation. Tilt the air conditioner slightly to the outside to allow for water drainage. Refer to the installation instructions or consult with the installer.
E
Eric MorrisSep 9, 2025
What to do if remote sensing is deactivating prematurely on my Keystone KSTHW08B?
- Q
  qosborneSep 10, 2025
  If the remote sensing is deactivating prematurely on your Keystone air conditioner (for some models): * Ensure the remote control is within 20 feet and a 180° radius of the front of the unit. * Make sure there are no obstructions blocking the remote control signal.

Summary

Important Safety Instructions

Read This Manual

Introduction to the manual's purpose and benefits for proper use and maintenance.

General Safety Warning Symbols

Explains the meaning of WARNING and CAUTION symbols used throughout the manual.

Electrical Safety Precautions

Crucial safety rules regarding power plugs, dedicated circuits, grounding, and cord usage.

Safe Operation and Handling Guidelines

Guidelines for safe operation, including handling wet conditions, water exposure, and unit modification.

Important Safety Instructions Continued

Usage and Handling Cautions

Cautions related to filter removal, cleaning agents, storm operation, and sharp edges.

Environmental and Storage Safety

Safety advice on room ventilation, avoiding special uses, and long-term storage.

User Capability and Power Cord Safety

Safety considerations for users with reduced capabilities and damaged power cords.

Further Safety Instructions

Power Cord Safety Features

Details on the power supply cord's current detection device and its function.

General Safety Warnings

Warnings against using extension cords, adapter plugs, and flammable liquids.

Installation and Handling Safety

Safety tips for electrical service, window installation, and handling sharp parts.

Electrical Grounding and Receptacle Requirements

Ensuring proper electrical grounding and wall receptacle compatibility.

Current Device Operation Test Procedure

Step-by-step guide to test the power supply cord's current detection device.

Operating Temperature Guidelines

Recommended outdoor and indoor temperature ranges for cooling and heating operation.

Installation Instructions

Installation Safety Precautions

Cautions regarding personal injury, property damage, and device handling during installation.

Required Tools and Parts List

Lists all necessary tools and supplied parts for installation.

Window Installation Procedures

Location and Window Opening Requirements

Specifies location requirements and window opening dimensions for proper installation.

Packaging Material Removal Instructions

Steps for safely removing and cleaning packaging materials from the unit.

Unit Preparation for Installation

Attaching Top Channel and Side Curtains

Instructions for attaching the top channel and side curtains to the air conditioner.

Removing Shipping Materials

Visual guide and notes for removing shipping screws and packaging from the unit.

Cabinet Installation Steps

Installing Cabinet into Window

Steps for attaching foam seal and centering/securing the cabinet in the window.

Attaching Side Curtains to Window Frame

Detailed instructions for securing the side curtains to the window frame.

Completing Installation

Completing Window Installation Steps

Final steps for window installation including bracket, unit insertion, and power connection.

Through-the-Wall Cabinet Installation Options

Guidance for installing the cabinet through a wall, with or without molding.

Installing the Wood Frame for Wall Installation

Instructions for constructing and installing a wood frame for through-the-wall mounting.

Through-the-Wall Installation Details

Installing Cabinet into Wood Frame

Steps for inserting and securing the air conditioner cabinet into a wood frame.

Finalizing Through-the-Wall Installation

Final steps for through-the-wall installation, including securing the unit and power connection.

Normal Sounds During Operation

Common Operating Sound Explanations

Explains typical sounds like rushing air, gurgling, chatter, vibration, and pinging.

Air Conditioner Features and Controls

Electronic Control Panel Overview

Introduction to the control panel and its main functions for operating the unit.

Turning the Unit On and Off

Instructions on how to power the air conditioner unit on and off.

Adjusting Temperature Settings

Guidance on how to change the desired temperature using the control buttons.

Advanced Air Conditioner Functions

Adjusting Fan Speeds

How to select fan speeds for optimal air circulation.

Sleep Mode Operation

Explanation of the Sleep mode feature and its automatic temperature adjustments.

Check Filter Reminder Feature

How the Check Filter feature works and how to reset the indicator.

Energy Saver Feature

Details on how the Energy Saver function helps conserve energy.

I-SENSE Remote Thermostat Function

How to use the I-SENSE feature for precise temperature control at the remote's location.

Selecting Operating Modes

How to choose between Auto, Cool, Dry, and Fan operating modes.

Auto Mode Operation

Explanation of how Auto mode automatically selects cooling, heating, or fan.

Fan Only Mode Operation

Instructions for using the Fan Only mode for air circulation or ventilation.

Dry Mode Operation

How the Dry mode functions as a dehumidifier for the room.

Timer Auto Start;Stop Feature

How to set the auto start and stop timer for the air conditioner unit.

Unit Displays and Airflow

Display Indicators and Error Codes

Explains display indicators, temperature units, and common error code meanings.

Air Directional Louver Adjustment

How to adjust the 4-way louvers for optimal airflow direction.

Additional Operating Information

Notes on compressor time delay start and converting temperature units.

Care and Cleaning

Air Filter Cleaning Procedure

Detailed steps for cleaning the air filter to maintain unit efficiency.

Maintenance and Storage

Cabinet Cleaning and Winter Storage

Instructions for cleaning the unit's cabinet and preparing it for winter storage.

Troubleshooting Common Problems

Initial steps to resolve common issues like the unit not starting.

Troubleshooting Tips

Troubleshooting Cooling Issues

Solutions for problems like insufficient cooling or ice formation on coils.

Troubleshooting Operational Issues

Solutions for rapid cycling, unit noise, and water dripping during operation.

Troubleshooting Remote and Temperature Issues

Solutions for remote sensing errors and rooms being too cold.

Summary

Important Safety Instructions

Read This Manual

Introduction to the manual's purpose and benefits for proper use and maintenance.

General Safety Warning Symbols

Explains the meaning of WARNING and CAUTION symbols used throughout the manual.

Electrical Safety Precautions

Crucial safety rules regarding power plugs, dedicated circuits, grounding, and cord usage.

Safe Operation and Handling Guidelines

Guidelines for safe operation, including handling wet conditions, water exposure, and unit modification.

Important Safety Instructions Continued

Usage and Handling Cautions

Cautions related to filter removal, cleaning agents, storm operation, and sharp edges.

Environmental and Storage Safety

Safety advice on room ventilation, avoiding special uses, and long-term storage.

User Capability and Power Cord Safety

Safety considerations for users with reduced capabilities and damaged power cords.

Further Safety Instructions

Power Cord Safety Features

Details on the power supply cord's current detection device and its function.

General Safety Warnings

Warnings against using extension cords, adapter plugs, and flammable liquids.

Installation and Handling Safety

Safety tips for electrical service, window installation, and handling sharp parts.

Electrical Grounding and Receptacle Requirements

Ensuring proper electrical grounding and wall receptacle compatibility.

Current Device Operation Test Procedure

Step-by-step guide to test the power supply cord's current detection device.

Operating Temperature Guidelines

Recommended outdoor and indoor temperature ranges for cooling and heating operation.

Installation Instructions

Installation Safety Precautions

Cautions regarding personal injury, property damage, and device handling during installation.

Required Tools and Parts List

Lists all necessary tools and supplied parts for installation.

Window Installation Procedures

Location and Window Opening Requirements

Specifies location requirements and window opening dimensions for proper installation.

Packaging Material Removal Instructions

Steps for safely removing and cleaning packaging materials from the unit.

Unit Preparation for Installation

Attaching Top Channel and Side Curtains

Instructions for attaching the top channel and side curtains to the air conditioner.

Removing Shipping Materials

Visual guide and notes for removing shipping screws and packaging from the unit.

Cabinet Installation Steps

Installing Cabinet into Window

Steps for attaching foam seal and centering/securing the cabinet in the window.

Attaching Side Curtains to Window Frame

Detailed instructions for securing the side curtains to the window frame.

Completing Installation

Completing Window Installation Steps

Final steps for window installation including bracket, unit insertion, and power connection.

Through-the-Wall Cabinet Installation Options

Guidance for installing the cabinet through a wall, with or without molding.

Installing the Wood Frame for Wall Installation

Instructions for constructing and installing a wood frame for through-the-wall mounting.

Through-the-Wall Installation Details

Installing Cabinet into Wood Frame

Steps for inserting and securing the air conditioner cabinet into a wood frame.

Finalizing Through-the-Wall Installation

Final steps for through-the-wall installation, including securing the unit and power connection.

Normal Sounds During Operation

Common Operating Sound Explanations

Explains typical sounds like rushing air, gurgling, chatter, vibration, and pinging.

Air Conditioner Features and Controls

Electronic Control Panel Overview

Introduction to the control panel and its main functions for operating the unit.

Turning the Unit On and Off

Instructions on how to power the air conditioner unit on and off.

Adjusting Temperature Settings

Guidance on how to change the desired temperature using the control buttons.

Advanced Air Conditioner Functions

Adjusting Fan Speeds

How to select fan speeds for optimal air circulation.

Sleep Mode Operation

Explanation of the Sleep mode feature and its automatic temperature adjustments.

Check Filter Reminder Feature

How the Check Filter feature works and how to reset the indicator.

Energy Saver Feature

Details on how the Energy Saver function helps conserve energy.

I-SENSE Remote Thermostat Function

How to use the I-SENSE feature for precise temperature control at the remote's location.

Selecting Operating Modes

How to choose between Auto, Cool, Dry, and Fan operating modes.

Auto Mode Operation

Explanation of how Auto mode automatically selects cooling, heating, or fan.

Fan Only Mode Operation

Instructions for using the Fan Only mode for air circulation or ventilation.

Dry Mode Operation

How the Dry mode functions as a dehumidifier for the room.

Timer Auto Start;Stop Feature

How to set the auto start and stop timer for the air conditioner unit.

Unit Displays and Airflow

Display Indicators and Error Codes

Explains display indicators, temperature units, and common error code meanings.

Air Directional Louver Adjustment

How to adjust the 4-way louvers for optimal airflow direction.

Additional Operating Information

Notes on compressor time delay start and converting temperature units.

Care and Cleaning

Air Filter Cleaning Procedure

Detailed steps for cleaning the air filter to maintain unit efficiency.

Maintenance and Storage

Cabinet Cleaning and Winter Storage

Instructions for cleaning the unit's cabinet and preparing it for winter storage.

Troubleshooting Common Problems

Initial steps to resolve common issues like the unit not starting.

Troubleshooting Tips

Troubleshooting Cooling Issues

Solutions for problems like insufficient cooling or ice formation on coils.

Troubleshooting Operational Issues

Solutions for rapid cycling, unit noise, and water dripping during operation.

Troubleshooting Remote and Temperature Issues

Solutions for remote sensing errors and rooms being too cold.

Keystone KSTHW08B Specifications

General

Brand	Keystone
Model	KSTHW08B
Category	Air Conditioner
Language	English

Related product manuals

Keystone KSTHW08B - User Manual

Table of Contents

Questions and Answers

Summary

Important Safety Instructions

Read This Manual

General Safety Warning Symbols

Electrical Safety Precautions

Safe Operation and Handling Guidelines

Important Safety Instructions Continued

Usage and Handling Cautions

Environmental and Storage Safety

User Capability and Power Cord Safety

Further Safety Instructions

Power Cord Safety Features

General Safety Warnings

Installation and Handling Safety

Electrical Grounding and Receptacle Requirements

Current Device Operation Test Procedure

Operating Temperature Guidelines

Installation Instructions

Installation Safety Precautions

Required Tools and Parts List

Window Installation Procedures

Location and Window Opening Requirements

Packaging Material Removal Instructions

Unit Preparation for Installation

Attaching Top Channel and Side Curtains

Removing Shipping Materials

Cabinet Installation Steps

Installing Cabinet into Window

Attaching Side Curtains to Window Frame

Completing Installation

Completing Window Installation Steps

Through-the-Wall Cabinet Installation Options

Installing the Wood Frame for Wall Installation

Through-the-Wall Installation Details

Installing Cabinet into Wood Frame

Finalizing Through-the-Wall Installation

Normal Sounds During Operation

Common Operating Sound Explanations

Air Conditioner Features and Controls

Electronic Control Panel Overview

Turning the Unit On and Off

Adjusting Temperature Settings

Advanced Air Conditioner Functions

Adjusting Fan Speeds

Sleep Mode Operation

Check Filter Reminder Feature

Energy Saver Feature

I-SENSE Remote Thermostat Function

Selecting Operating Modes

Auto Mode Operation

Fan Only Mode Operation

Dry Mode Operation

Timer Auto Start;Stop Feature

Unit Displays and Airflow

Display Indicators and Error Codes

Air Directional Louver Adjustment

Additional Operating Information

Care and Cleaning

Air Filter Cleaning Procedure

Maintenance and Storage

Cabinet Cleaning and Winter Storage

Troubleshooting Common Problems

Troubleshooting Tips

Troubleshooting Cooling Issues

Troubleshooting Operational Issues

Troubleshooting Remote and Temperature Issues

Summary

Important Safety Instructions

Read This Manual

General Safety Warning Symbols

Electrical Safety Precautions

Safe Operation and Handling Guidelines

Important Safety Instructions Continued

Usage and Handling Cautions

Environmental and Storage Safety

User Capability and Power Cord Safety

Further Safety Instructions