Mr. Heater Big Buddy Manual: A Comprehensive Guide
This comprehensive guide details the operation and maintenance of the Mr. Heater Big Buddy, ensuring safe and efficient heating;
It covers instructions, warnings, and troubleshooting for optimal performance.
Access detailed manuals, operating instructions, and safety precautions for your Mr. Heater Big Buddy, including the MH18B model.
Always read the manual carefully before use, paying close attention to warnings regarding carbon monoxide and proper ventilation.
The Mr. Heater Big Buddy is a portable propane radiant heater designed for both indoor and outdoor use, providing a reliable heat source in various environments. This manual serves as a crucial resource for understanding its features, safe operation, and maintenance procedures.
Designed for convenience, the Big Buddy offers multiple heat settings and a backup power option, enhancing its versatility.
It’s essential to thoroughly review these instructions before initial use to ensure safe and effective heating.
Proper understanding of the manual is paramount for preventing hazards.
Understanding the Big Buddy Model (MH18B)
The Mr. Heater Big Buddy MH18B is a powerful and versatile portable heater, capable of providing significant warmth for spaces up to 400 square feet. It features multiple heat settings – low, medium, and high – allowing for customized temperature control.
This model distinguishes itself with a built-in battery backup for the igniter and fan, ensuring operation even during power outages. Understanding its regulator system is vital, as it controls propane flow. Always inspect the hose and connections before each use.

Safety Precautions
Prioritize safety when using your Mr. Heater Big Buddy. Always ensure adequate ventilation, inspect for gas leaks, and heed carbon monoxide warnings.
Never leave the heater unattended while operating, and follow all instructions carefully.
Carbon Monoxide Warnings
Carbon monoxide (CO) is a colorless, odorless, and deadly gas. The Mr. Heater Big Buddy, while designed for safety, can produce CO if used improperly. Always use in a well-ventilated area, and never operate indoors or in enclosed spaces.
Install a carbon monoxide detector near the heater and regularly test its functionality. Be aware of CO poisoning symptoms: headache, dizziness, nausea, and shortness of breath. If symptoms occur, immediately get fresh air and seek medical attention. Ignoring these warnings can be fatal.
Proper Ventilation Requirements
Adequate ventilation is crucial when operating the Mr. Heater Big Buddy. Ensure at least 4 square feet of unobstructed ventilation opening. This allows sufficient fresh air for complete combustion and prevents CO buildup. Avoid using in basements, RVs, or other confined areas.
Maintain airflow by opening windows or doors while the heater is running. Never block ventilation openings with objects or furniture. Regularly check for proper airflow to ensure safe operation. Failure to ventilate adequately can lead to dangerous CO levels.
Safe Fuel Handling Procedures
Always inspect the propane cylinder for damage before connecting it to the Mr. Heater Big Buddy. Ensure the connection is tight and leak-free using a soapy water solution. Store propane cylinders outdoors in a well-ventilated area, away from heat sources.
Never store a spare propane cylinder near the heater during operation. Replace damaged or corroded cylinders immediately. Follow all local regulations regarding propane storage and handling. Disconnect the cylinder when the heater is not in use.

Component Identification
Familiarize yourself with the heater body, regulator, hose assembly, burner, and ignition system. Understanding these components is crucial for safe operation and maintenance.
Locate the power switch, heat indicators, and piezo igniter on the control panel. Proper identification aids in troubleshooting and effective use.
Heater Body and Construction
The Mr. Heater Big Buddy features a robust heater body designed for durability and portability. Its construction utilizes high-quality materials to withstand various environmental conditions. The radiant surface efficiently distributes heat, providing warmth in a wide area.
The body encases the burner assembly and regulator, protecting them from damage. It’s designed with a sturdy base for stability during operation. Inspect the body for any signs of damage before each use, ensuring all components are securely fastened. Proper care extends the heater’s lifespan.
Regulator and Hose Assembly
The regulator and hose assembly are critical components for safe and efficient propane delivery. The regulator maintains consistent gas pressure, ensuring stable heater operation. Inspect the hose for cracks, abrasions, or leaks before each use. Ensure the hose is securely connected to both the propane cylinder and the heater.
Never operate the heater if the regulator or hose shows any signs of damage. Replace damaged parts immediately with manufacturer-approved replacements. Proper maintenance of this assembly is vital for preventing gas leaks and ensuring safe heating.
Burner and Ignition System
The burner is where propane combustion occurs, generating heat. A clean burner ensures efficient and complete combustion. The ignition system, typically a piezo igniter, creates the spark to ignite the propane-air mixture; Regularly inspect the burner for debris or obstructions, cleaning as needed.
Ensure the piezo igniter produces a strong, consistent spark. If the igniter fails, follow the manual’s instructions for alternative lighting methods. A properly functioning burner and ignition system are essential for safe and reliable heater operation.

Setting Up Your Big Buddy
Proper setup is crucial for safe operation. Connect the propane cylinder securely, inspect connections, and position the heater on a level surface.
Ensure adequate ventilation and follow all instructions in the manual before initial use.
Connecting the Propane Cylinder
Carefully connect the propane cylinder to the regulator assembly, ensuring a tight and secure connection. Always inspect the cylinder and hose for damage before each use.
Hand-tighten the connection; avoid using tools, as over-tightening can damage the valve.
Only use a 1 lb. disposable propane cylinder designed for outdoor heaters. Verify the regulator is properly attached to both the cylinder and the heater;
Never attempt to connect a larger propane tank without the appropriate adapter.
Periodically check for gas leaks using a soapy water solution.
Initial Inspection Before Use
Before each use, thoroughly inspect the Mr. Heater Big Buddy for any signs of damage. Check the hose for cracks, abrasions, or kinks, and ensure the regulator is securely attached. Examine the burner for obstructions or debris.
Verify the power switch is in the “OFF” position before connecting the propane cylinder. Inspect the propane cylinder itself for dents, rust, or leaks. Ensure adequate ventilation is available.
Never operate a damaged heater; contact Mr. Heater for assistance.
Placement and Positioning for Optimal Heating
Position the Mr. Heater Big Buddy on a level, stable surface, clear of combustible materials like paper or fabrics. Maintain a minimum distance of three feet from walls, furniture, and overhead obstructions.
Ensure adequate ventilation is present, especially in enclosed spaces. Avoid placing the heater in windy areas, as this can affect performance. Never operate the heater in a sleeping area without proper ventilation.
Proper positioning maximizes heat distribution and ensures safe operation.
Operating Instructions
Follow the step-by-step lighting instructions carefully. Adjust heat output levels using the control panel. Monitor the flame and operation consistently for safety.
Never leave the heater unattended while burning, and always inspect connections before each use.
Lighting the Heater – Step-by-Step
First, fully open the propane cylinder valve. Then, turn the control knob to the “OFF” position. Next, slowly turn the control knob to the “Pilot” setting, pressing and holding the piezo igniter button. Continue pressing the igniter until a steady pilot flame appears.
Once the pilot is lit, release the control knob. Turn the knob to the desired heat setting – “Low” or “High”. If the heater fails to light, repeat the process, ensuring proper gas flow and ignition. Always observe the flame for stability and proper operation.
Adjusting Heat Output Levels
The Mr. Heater Big Buddy offers multiple heat settings for customized comfort. To increase heat, slowly rotate the control knob clockwise towards the “High” setting. For lower heat output, turn the knob counterclockwise to the “Low” position.
Monitor the flame and adjust accordingly to achieve the desired temperature. Be cautious when transitioning between settings, allowing the heater to stabilize. Avoid rapid adjustments. Ensure adequate ventilation is maintained regardless of the heat level selected.
Monitoring Flame and Operation
Regularly observe the burner flame during operation; it should be a clear, blue flame. A yellow or orange flame indicates incomplete combustion and potential carbon monoxide production. If this occurs, immediately turn off the heater and address the issue.
Listen for consistent gas flow and ensure the heater operates smoothly. Check the hose for any signs of damage or leaks. Never leave the heater unattended while in use, and maintain a safe distance from flammable materials.

Understanding the Control Panel
The control panel features a power switch, low/high heat indicators, and a piezo igniter. These controls manage heat output and ignition for safe operation.
Familiarize yourself with each function for optimal performance and efficient heating with your Mr. Heater Big Buddy.
Power Switch and Settings
The power switch on your Mr. Heater Big Buddy controls the unit’s operation, offering distinct settings for heating needs. Typically, it features an “Off,” “Low,” and “High” position. The “Off” position completely shuts down the heater, ensuring no gas flow.
Selecting “Low” provides a reduced heat output, ideal for smaller spaces or moderate temperatures. “High” delivers maximum BTU output for quickly heating larger areas or during colder conditions. Always ensure the power switch is in the “Off” position when not in use or during maintenance.
Low/High Heat Indicators
The Mr. Heater Big Buddy features clear indicators to display the selected heat output level. These indicators, often illuminated lights, visually confirm whether the heater is operating on the “Low” or “High” setting. The presence of a lit indicator assures the user that the chosen heat level is active.
These indicators are crucial for monitoring the heater’s performance and ensuring the desired temperature is maintained. If an indicator isn’t lit when the heater is on, it may signal a malfunction requiring immediate attention. Regularly check these indicators during operation.
Piezo Igniter Functionality
The Mr. Heater Big Buddy utilizes a piezo igniter for convenient and reliable lighting. This system generates a high-voltage spark when the ignition button is depressed, igniting the propane gas. A firm and deliberate press is required for successful ignition. Listen for a clicking sound confirming spark generation.
If the heater fails to light after several attempts, check the gas supply and ensure the burner is clean. Avoid prolonged pressing of the igniter button to conserve its lifespan. The piezo igniter eliminates the need for matches or lighters.

Maintenance and Care
Regular cleaning of the burner assembly and inspection of the regulator and hose are crucial. Proper propane cylinder storage ensures longevity and safety.
Consistent maintenance maximizes the heater’s efficiency and extends its operational life, following the manual’s guidelines.
Cleaning the Burner Assembly
To clean the burner assembly, first ensure the heater is completely cool and the propane cylinder is disconnected. Carefully remove the burner assembly according to the manual’s instructions. Use a soft brush or compressed air to remove any dust, debris, or spider webs from the burner ports.
Avoid using water or solvents, as these can damage the components. Inspect the burner for any signs of corrosion or damage, replacing it if necessary. Reinstall the burner assembly securely, ensuring proper alignment. A clean burner ensures efficient combustion and optimal heater performance.
Inspecting the Regulator and Hose
Regularly inspect the regulator and hose assembly for any signs of damage, such as cracks, abrasions, or leaks. Before each use, visually check the hose for wear and tear. To check for leaks, apply a soapy water solution to the connections while the heater is running.
Bubbles indicate a leak; immediately shut off the propane and address the issue. Ensure the regulator is securely attached to both the cylinder and the heater. Replace damaged components immediately; never attempt to repair them.
Propane Cylinder Storage Guidelines
Store propane cylinders outdoors in a well-ventilated area, away from heat sources, direct sunlight, and ignition sources. Keep cylinders upright and secured to prevent accidental tipping. Never store a connected cylinder inside a closed space, like a home or garage.
Disconnect the cylinder from the heater when not in use and cap the valve for protection. Follow all local and state regulations regarding propane storage. Inspect cylinders regularly for rust or damage before each use.
Troubleshooting Common Issues
This section addresses frequent problems like failure to ignite, low heat output, and potential gas leaks. Follow the provided steps for safe resolution.
Inspect connections, regulator function, and burner cleanliness to diagnose and correct operational issues with your Big Buddy heater.
Heater Won’t Light
If your Mr. Heater Big Buddy fails to ignite, first ensure the propane cylinder is full and properly connected. Check the regulator and hose assembly for any damage or obstructions. Verify the burner is clean and free of debris.
Next, test the piezo igniter by pressing the button firmly while simultaneously turning the control knob to the “High” setting. If it still doesn’t light, try a different propane cylinder. Always follow the lighting instructions carefully, and never attempt to light the heater multiple times in succession.
Low Heat Output
If your Mr. Heater Big Buddy produces insufficient heat, first confirm the propane cylinder is adequately full. A low propane level significantly reduces heating capacity. Inspect the burner for any blockages, such as dirt or debris, hindering proper combustion.
Ensure the heater is positioned correctly for optimal airflow and isn’t obstructed. Verify the regulator is functioning correctly; a faulty regulator can restrict gas flow. Try switching to the “High” setting to see if output improves.
Gas Leak Detection
If you suspect a gas leak, immediately shut off the propane cylinder valve. Never attempt to light the heater if a leak is present. Create a soapy water solution and apply it to all connections – the regulator, hose, and cylinder connection.
Bubbles indicate a leak; tighten the connections or replace damaged components. Ensure adequate ventilation and evacuate the area if the leak persists. Contact a qualified technician for assistance if you cannot resolve the issue;

Specific Model Features (MH18B)
The MH18B Big Buddy offers back-up power, multiple heat settings, and an integrated carrying handle, enhancing convenience and versatility for various heating needs.
Back-Up Power Option
The Mr; Heater Big Buddy MH18B boasts a unique back-up power feature, allowing operation even without electricity for the igniter. This is incredibly valuable during power outages or when off-grid heating is required.
The heater can be lit manually with a match if the piezo igniter fails, ensuring continued warmth. This feature provides peace of mind and reliable heating in emergency situations. Always follow the manual’s instructions for manual lighting to ensure safe operation and prevent gas buildup.
This dual functionality makes the Big Buddy a dependable heating solution, offering resilience and adaptability beyond standard propane heaters.
Multiple Heat Settings Explained
The Mr. Heater Big Buddy MH18B offers multiple heat settings to customize your comfort level and conserve fuel. These settings typically include Low, Medium, and High, providing varying BTU outputs. Understanding these settings is crucial for efficient operation.
The Low setting is ideal for smaller spaces or milder temperatures, while the High setting delivers maximum heat for colder conditions. Adjusting the heat output allows you to maintain a comfortable temperature without overheating or wasting propane. Refer to the manual for specific BTU ratings for each setting.
Integrated Carrying Handle
The Mr. Heater Big Buddy is designed with portability in mind, featuring a robust, integrated carrying handle. This handle allows for easy transportation of the heater, making it convenient for camping, job sites, or emergency preparedness. The handle is securely attached to the heater body, ensuring a safe and comfortable grip.
Its placement is strategically designed to balance the weight of the unit, minimizing strain during transport. This feature enhances the Big Buddy’s versatility, allowing you to quickly move it to where heat is needed most, providing warmth wherever you go.

Technical Specifications
The Mr. Heater Big Buddy boasts varying BTU outputs and propane consumption rates. Dimensions and weight are crucial for portability, ensuring efficient heating performance.
Refer to the manual for precise specifications of your MH18B model, including heating area details.
BTU Output and Heating Area
The Mr. Heater Big Buddy MH18B delivers a robust heating capacity, with a maximum BTU output of 18,000 BTU. This allows it to effectively warm spaces up to 400 square feet. However, actual heating area depends on factors like insulation, wind conditions, and altitude.
The heater offers multiple heat settings, ranging from low (9,000 BTU) to high (18,000 BTU), providing customizable warmth. Consult your owner’s manual for detailed BTU output information and recommended room sizes for optimal performance. Proper usage ensures efficient and safe heating.
Propane Consumption Rate
The Mr. Heater Big Buddy’s propane consumption varies based on the selected heat setting. At the high setting (18,000 BTU), it consumes approximately 1.08 lbs of propane per hour. On the low setting (9,000 BTU), consumption drops to around 0.54 lbs per hour.
A standard 1 lb propane cylinder will provide roughly 5-10 hours of runtime on the low setting, and 2.5-5 hours on high. Always refer to your owner’s manual for precise consumption rates and cylinder sizing recommendations for extended operation.
Dimensions and Weight
The Mr. Heater Big Buddy (MH18B) is designed for portability while delivering substantial heat. Its dimensions are approximately 31.5 inches in height, 16.3 inches in width, and 18.1 inches in depth. These compact dimensions facilitate easy storage and transport.
The unit weighs around 17.4 pounds when empty, making it manageable for most users. The integrated carrying handle further enhances portability, allowing for convenient relocation as needed. Always check the manual for exact specifications.

Warranty Information
Mr. Heater provides a limited warranty covering defects in materials and workmanship. Coverage details, claim procedures, and limitations are outlined in the owner’s manual.
Review the warranty information carefully to understand your rights and responsibilities. Proper registration may be required to validate your warranty claim.
Coverage Details
The Mr. Heater Big Buddy warranty typically covers defects in materials and workmanship for a specified period from the date of original purchase. This generally includes issues with the burner assembly, regulator, and heater body itself. However, the warranty does not cover damage resulting from misuse, abuse, improper installation, or lack of maintenance.
Normal wear and tear, accidental damage, and modifications are also excluded from coverage. The warranty is valid only if the heater is used in accordance with the owner’s manual instructions. Proof of purchase is essential for any warranty claim. Specific warranty durations vary by model and region.
Claim Procedures
To initiate a warranty claim for your Mr. Heater Big Buddy, first contact the original retailer where the heater was purchased. If the retailer is unable to resolve the issue, contact Mr. Heater’s customer service department directly. You will need to provide proof of purchase, a detailed description of the defect, and potentially photos or videos.
Mr. Heater may request that the defective heater be returned for inspection. Shipping costs for returns may be the responsibility of the consumer. Approved claims will typically result in repair or replacement of the defective part or unit.
Limitations and Exclusions
The Mr. Heater Big Buddy warranty does not cover damage resulting from misuse, abuse, neglect, or improper installation. Normal wear and tear, accidental damage, and cosmetic issues are also excluded from coverage. Modifications to the heater or use of non-approved accessories will void the warranty.
Furthermore, the warranty does not cover damage caused by acts of God, such as floods or lightning. Claims arising from improper fuel usage or failure to follow operating instructions are also not covered. This warranty is non-transferable.
California Specific Information
California residents are warned about Proposition 65 exposure risks. Ensure compliance with California Air Quality Regulations when operating your Mr. Heater Big Buddy.
Refer to the manual for specific California requirements and safety advisories related to propane heater usage.
Proposition 65 Warning
California’s Proposition 65 requires businesses to provide warnings about significant exposures to chemicals known to the state to cause cancer, birth defects, or other reproductive harm.
The Mr. Heater Big Buddy, like many appliances using combustion, may contain or produce substances listed under Proposition 65. These substances can include carbon monoxide, a known reproductive toxin.
Using this heater may expose you to these chemicals. Always operate the heater in a well-ventilated area and follow all safety instructions outlined in the owner’s manual to minimize exposure.
For more information about Proposition 65, visit the California Office of Environmental Health Hazard Assessment website.
California Air Quality Regulations
California has stringent air quality regulations concerning the use of fuel-burning appliances, including propane heaters like the Mr. Heater Big Buddy. These regulations aim to reduce emissions and protect public health.
Ensure your Big Buddy meets California’s emission standards before operation within the state. Compliance often involves specific burner designs and emission control systems.
Always check local air quality regulations and restrictions before using the heater, particularly during periods of air quality alerts. Proper ventilation is crucial for compliant and safe operation.
Refer to the California Air Resources Board (CARB) website for the most up-to-date information on applicable regulations.

Spanish Language Warnings (Aviso/Advertencia)
Key safety instructions are translated into Spanish (Aviso/Advertencia) for users. Understanding Spanish safety labels is vital for proper operation and preventing accidents.
Refer to the manual for translated warnings regarding carbon monoxide, ventilation, and fuel handling.
Translation of Key Safety Instructions
The Mr. Heater Big Buddy manual provides crucial safety information translated into Spanish, designated as “Aviso/Advertencia.” These translations cover essential warnings regarding carbon monoxide poisoning, emphasizing the dangers of indoor use without adequate ventilation.
Instructions concerning proper propane cylinder handling, connection procedures, and leak detection are also translated. Users will find warnings about never leaving the heater unattended while in operation and the importance of keeping combustible materials away.
These Spanish translations ensure broader accessibility and understanding of safety protocols, promoting safe operation for all users, regardless of their primary language.
Understanding Spanish Safety Labels
The Mr. Heater Big Buddy incorporates Spanish safety labels (“Etiquetas de seguridad”) alongside English versions, enhancing comprehension for a wider user base. These labels directly translate critical warnings regarding carbon monoxide risks and the necessity of outdoor or well-ventilated use.
Key phrases like “PELIGRO” (Danger) and “ADVERTENCIA” (Warning) are prominently displayed, immediately drawing attention to potential hazards. Labels also detail safe fuel handling practices and the prohibition of modifying the heater.
Understanding these Spanish labels is vital for ensuring all operators recognize and adhere to the safety guidelines, preventing accidents and promoting responsible heater usage.