Gas vs Electric Pool Heaters: Which Is Best for Phoenix Pools?

Gas vs Electric Pool Heaters: Which Is Best for Phoenix Pools?

Want to swim year-round in Phoenix? Extend your pool season into November through March? You’ll need a pool heater. But which type - gas or electric heat pump?

Let’s compare the two main options for Arizona pools. For installation and service, explore our pool equipment services.

Quick Comparison

Factor	Gas Heater (Natural Gas)	Heat Pump (Electric)
Heating Speed	Fast (1-2 degrees/hour)	Slow (1 degree/hour)
Monthly Operating Cost	High ($300-$500+)	Low ($50-$100)
Upfront Cost	Lower ($1,500-$3,000)	Higher ($3,000-$5,000)
Best For	Spas & Weekends	Daily Swimming
Lifespan	8-12 years	15-20 years
Cold Weather	Works at any temp	Less efficient below 50°F

Gas Pool Heaters

Gas heaters burn natural gas or propane to heat water quickly and powerfully.

How Gas Heaters Work

Pool water flows through a heat exchanger while gas burners below heat the copper tubes. Simple, proven technology used for decades.

Gas Heater Pros

Fast heating: Raise pool temperature 20-30°F in just a few hours. This speed is perfect for “I want to swim tonight” situations.

Works in any weather: Cold, cloudy, windy - doesn’t matter. Gas heaters deliver full power regardless of the air temperature outside.

Lower purchase price: Entry-level gas heaters generally start around $1,500 to $2,500 installed.

Compact size: These units typically have a smaller footprint than heat pumps.

Gas Heater Cons

Higher operating costs: Natural gas isn’t cheap. Southwest Gas rates fluctuate, and heating a standard pool might cost $20 to $40 for a single weekend.

Shorter lifespan: The copper heat exchangers eventually corrode. You can expect a typical lifespan of 8 to 12 years.

Requires gas line: If you don’t have natural gas at the equipment pad, running a new line adds significant complexity and cost.

Not efficient for maintaining temperature: These are best for heating up quickly rather than keeping the water warm 24/7.

Electric Heat Pumps

Heat pumps don’t create heat - they transfer it from the air to your pool water.

How Heat Pumps Work

A fan draws in warm air, and a compressor concentrates that heat (like a reverse air conditioner). The heat transfers to pool water flowing through the unit.

Heat Pump Pros

Low operating cost: Because they move heat rather than creating it, these units are 300% to 500% efficient. Heating that same pool might cost just $3 to $5 per session.

Long lifespan: They use titanium heat exchangers which are nearly impervious to pool chemical corrosion. Expect 15 to 20 years with proper care.

Maintains temperature economically: This is the perfect solution for keeping a pool warm continuously for daily swimming.

No combustion: You won’t need a gas line, exhaust venting, or worry about combustion safety.

Heat Pump Cons

Slow heating: Adding 20°F takes 12 to 24+ hours. We tell clients this is not for last-minute warm-ups.

Higher purchase price: Quality heat pumps generally run $3,000 to $5,000 installed.

Weather dependent: Efficiency drops as air temperature falls. Below 50°F, most standard units struggle to extract heat.

Larger footprint: Heat pumps are physically bigger than gas heaters and need more clearance.

Needs airflow: You must install these outdoors with plenty of space for air circulation.

Real-World Cost Comparison

Let’s look at the math for heating a 15,000-gallon pool from 60°F to 82°F in Phoenix.

Cost Breakdown:

Factor	Gas Heater	Heat Pump
Time to heat	3-5 hours	18-30 hours
Energy used	~8 therms gas	~25 kWh
Cost estimate (2025/26)	$15-$25 per heat-up	$3-$6 per heat-up

For occasional use (weekend swim):

• Gas: Heat Friday evening, swim Saturday.
• Heat pump: Start Wednesday to swim Saturday.

For maintaining temperature:

• Gas: Extremely expensive to run continuously ($400+ monthly).
• Heat pump: Affordable to keep warm 24/7 ($50-$100 monthly).

Pro Tip: In Phoenix, evaporation is the biggest thief of heat. We strongly recommend using a liquid solar cover or a bubble blanket. Without one, you are paying to heat the dry desert air.

Which Is Right for Arizona?

Choose a Gas Heater If:

• You swim only occasionally (weekends, guests, etc.).
• You want “swim on demand” capability.
• You already have natural gas service at the pool pad.
• You heat a spa that needs quick warm-up (15-20 minutes).
• Your budget favors lower upfront cost over long-term savings.

Choose a Heat Pump If:

• You want to swim regularly (multiple times weekly).
• You plan to maintain temperature throughout the season.
• You want the lowest possible monthly operating costs.
• You are extending the season (March-May, September-November).
• You plan to stay in the home long-term to see the ROI.

The Arizona Factor

Phoenix’s climate actually makes heat pumps very effective for most of the year.

Our advantages:

• Mild winter temps: Daytime highs in the 60s and 70s are perfect for heat pump efficiency.
• Abundant sunshine: This warms the air quickly, boosting performance.
• Low humidity: While this increases evaporation, it generally keeps the unit coils from freezing up.
• Long shoulder seasons: You get excellent value during the long spring and fall months.

The catch: If you only swim during summer, you might not need a heater at all! Arizona pools reach comfortable temps naturally from May through September.

Solar Pool Heating: The Third Option

Worth mentioning: solar heating uses roof-mounted panels to warm pool water for free (after installation).

Solar pros:

• Zero operating cost.
• Environmentally friendly.
• Long lifespan (20+ years).

Solar cons:

• Highest installation cost ($4,000-$8,000).
• Requires significant south or west-facing roof space.
• Only works during sunny hours.
• Can’t heat quickly or maintain temp overnight.

Solar works well in Arizona as a supplement or primary heater for extended seasons.

Combination Systems

Many Phoenix pool owners get the best of both worlds with a hybrid approach.

Heat pump + gas backup:

• The heat pump maintains temperature affordably during the week.
• The gas heater boosts the spa quickly when you want a soak.
• This offers maximum flexibility.

Cost: This has a higher upfront investment, but it delivers the lowest operating costs and best convenience.

Our Recommendation

For most Phoenix homeowners who want to extend their swimming season:

Best value: Electric heat pump. The operating savings pay back the higher upfront cost within 2-3 seasons, and Arizona’s climate is ideal for heat pump efficiency.

Best convenience: Gas heater (if you already have gas service). Nothing beats the ability to swim warm within hours.

Best overall: Combination system for those who can invest upfront.

Installation Considerations

For gas heaters:

• Need a gas line run to the equipment pad.
• Require proper venting to prevent carbon monoxide buildup.
• Must meet strict code clearances from windows and property lines.

For heat pumps:

• Need a dedicated 50-amp electrical circuit (check your breaker box space!).
• Require adequate airflow space around the unit (no bushes or walls too close).
• Should be level and supported on a concrete pad.

Both need professional installation to ensure safety, efficiency, and warranty coverage.

Ready to extend your swimming season? Contact us for a free consultation and we’ll help you choose the right heater for your pool and lifestyle.