Best Gas Heaters for Home and Hot Water

Choosing the right gas heater for a house depends on whether you need space heating or whole-house hot water. Below is a quick comparison of five gas-powered units suited for residential use, including tankless water heaters and indoor wall/infrared heaters. This guide summarizes key specs to help you match features to your home’s needs.

Product	Type	Key Capacity	Best For
Mr. Heater MHVFRD20NGT	Vent-Free Radiant Wall Heater	20,000 BTU	Supplemental room heating up to ~700 sq. ft.
Dyna-Glo IR30NMDG-1	Infrared Wall Heater	30,000 BTU	Larger spaces up to ~1,000 sq. ft.
Rheem RTG-95DVLN-3	Indoor Tankless Water Heater	9.5 GPM	Whole-house hot water for multiple fixtures
Rinnai V75IN	Tankless Hot Water Heater	7.5 GPM	Compact, continuous hot water
CAMPLUX 150,000 BTU	Tankless Water Heater	5.28 GPM, 150,000 BTU	Fast recovery for multiple outlets

Mr. Heater Vent Free Radiant 20,000 BTU

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This vent-free radiant wall heater produces 20,000 BTU designed to warm up to about 700 square feet. Its infrared-style output warms objects and people directly, which can feel more efficient in certain room types such as garages, sunrooms, or supplemental living spaces.

Key features listed include advanced infrared technology and an automatic low-oxygen shut-off system. The oxygen sensor interrupts gas supply if oxygen levels drop, a notable safety feature for indoor vent-free appliances.

Considerations: Vent-free units can raise indoor moisture and combustion byproducts compared with vented systems. They are suited for supplemental heating in well-ventilated spaces and where local codes permit vent-free gas appliances.

Dyna-Glo 30,000 BTU Infrared Wall Heater

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This infrared wall heater offers up to 30,000 BTU, intended for larger areas up to about 1,000 square feet. It uses radiant heating to warm surfaces first, providing steady, sun-like warmth that can be effective in open garages, workshops, or large rooms.

The product features infrared technology for direct radiant heat and is specified as natural gas ready. The manufacturer notes that fuel conversion is not permitted, so ensure your gas supply matches the unit’s requirements.

Considerations: Infrared heaters are efficient for targeted zones but may be less suitable as a primary heat source in colder climates without complementary systems. Check ventilation and installation clearances per local codes.

Rheem High Efficiency 9.5 GPM Tankless Heater

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The Rheem RTG-95DVLN-3 is a high-efficiency indoor tankless water heater rated at 9.5 GPM, designed to supply continuous hot water for whole-house needs. It supports simultaneous use of multiple fixtures like showers and dishwashers.

Highlighted features include continuous hot water delivery, high operational efficiency that reduces run-time, and a water-saving mode that can save significant gallons annually. The unit operates only when hot water is needed, helping lower energy usage.

Considerations: Indoor tankless installations require proper venting and gas sizing. For whole-house use, confirm your peak demand and inlet water temperatures to ensure the stated GPM meets your household’s simultaneous usage.

Rinnai V75IN Tankless Hot Water Heater

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The Rinnai V75IN is a compact tankless natural gas water heater offering up to 7.5 GPM to supply multiple household appliances. It emphasizes endless hot water flow and a small footprint suitable for space-conscious installations.

Important features include energy-saving on-demand operation, enhanced scale detection to reduce long-term damage risk, and an advertised high-performance flow that can serve several outlets concurrently.

Considerations: While compact, the unit’s GPM rating is lower than some larger models, so verify the number of simultaneous fixtures it will need to support in your home. Regular maintenance to manage scale is beneficial in hard-water areas.

CAMPLUX 150,000 BTU 5.28 GPM Tankless Heater

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The CAMPLUX unit pairs a high BTU input with a 5.28 GPM output and a claimed 96.9% efficient copper heat exchanger. It advertises very fast hot water delivery—within seconds—and consistent temperature control via advanced sensors.

Key features list oxygen-free copper heat exchanger for fuel savings, rapid heating, and precise temperature stability. The compact design reduces installation footprint compared with traditional tank systems.

Considerations: Higher BTU input can improve flow rates in cold climates but requires adequate gas supply and proper venting. For whole-house performance, compare GPM ratings to your typical simultaneous demand and confirm installation requirements.

Buying Guide: How To Choose The Right Gas Heater For Your Home

Selecting a gas heater involves assessing function, location, safety, and operating costs. Below are key considerations and comparison perspectives to guide a well-informed decision.

1. Identify The Purpose: Space Heating Vs. Hot Water

Decide whether you need a space heater (for rooms, garages, sunrooms) or a tankless water heater (for domestic hot water). Space heaters are measured in BTU output and coverage area. Tankless water heaters are rated in GPM and BTU input for water heating capacity.

2. Heating Capacity And Coverage

• Space Heaters: Estimate the square footage and insulation quality. Use BTU ratings as a guide—higher BTU covers larger, colder, or poorly insulated spaces.
• Tankless Water Heaters: Compare GPM at expected inlet temperatures. Colder climate inlet water reduces effective GPM, so choose a higher-rated unit for cold regions or simultaneous fixtures.

3. Venting And Installation Requirements

Indoor gas appliances require proper venting or must be explicitly listed as vent-free. Vent-free units deliver combustion byproducts to the room and may be restricted by local codes.

• Confirm indoor/outdoor designation and vent type before purchase.
• Ensure gas line capacity and appropriate BTU supply for high-BTU tankless units.

4. Safety Features And Compliance

Look for safety features such as oxygen depletion sensors (ODS), automatic shut-off functions, flame failure protection, freeze protection for outdoor units, and certifications from recognized testing labs. Check local code compliance for vent-free or high-BTU appliances.

5. Efficiency And Operating Costs

High-efficiency models reduce fuel consumption over time. For water heaters, on-demand operation and high thermal efficiency lower energy use compared to tank systems. Compare UEF or stated efficiency, and consider heat exchanger materials (copper vs. stainless steel) for long-term performance.

6. Number Of Fixtures And Simultaneous Use

For tankless water heaters, list typical simultaneous uses (e.g., two showers + dishwasher) and add their GPM needs to ensure the selected unit meets peak demand. For space heating, consider whether the unit is supplemental or primary.

7. Emissions, Ventilation, And Indoor Air Quality

Vent-free heaters can affect indoor humidity and combustion gas concentrations. Use carbon monoxide detectors and ensure adequate ventilation. Vented systems direct combustion products outside, improving indoor air quality.

8. Size, Location, And Maintenance

• Tankless units save floor space but may need periodic descaling in hard water areas.
• Wall-mounted space heaters require clearances and might need wall reinforcement.
• Factor in service accessibility for routine inspections and repairs.

9. Noise And User Controls

Some high-BTU tankless units or fans in space heaters can produce noise. Look for models with precise temperature control, digital displays, and consistent flow regulation if comfort and quiet operation are priorities.

10. Local Codes, Incentives, And Professional Installation

Always verify local building codes regarding vent-free equipment and gas appliance installations. Professional installation ensures safe venting, proper gas sizing, and compliance. Also check for rebates or efficiency incentives for high-efficiency units.

Comparative Perspective Summary:

• If your goal is supplemental room heat, consider infrared or vent-free wall heaters sized to room BTU needs, noting indoor air effects and code restrictions.
• For whole-house hot water, prioritize GPM at your inlet temperature, high thermal efficiency, and robust safety/venting requirements.
• High BTU tankless units deliver faster recovery and higher flow but require sufficient gas supply and correct venting.