Gas vs. Heat Pump Pool Heater in Houston: Cost, Speed, and Which to Buy

For most Houston pools, a gas heater is the better fit. It heats several times faster than a heat pump, it works in any weather, and at Houston's gas prices it costs only a few dollars more per heat-up.

A heat pump is the better tool for one kind of owner: the one who wants the water kept warm for weeks at a time. Here is how to tell which you are, with the numbers behind it.

Gas vs. heat pump at a glance

Last updated November 2026. Running costs use CenterPoint and EIA rates from that month.

	Gas heater	Heat pump
Installed cost	$3,500–$6,500	$3,500–$6,500
One 15°F heat-up	About $27	About $21–$26
Heating speed	About 2°F per hour	Usually under 1°F per hour
On a cold night	Full output in any weather	About 39% less heat at 50°F
Typical lifespan	7–10 years	10–15 years
Best for	Weekends, holidays, and spas	Keeping the pool warm for weeks

Installed costs are typical prices to replace an existing heater. Heat-up figures are for an 18,000-gallon pool. The detail behind both is under what a new heater costs installed and what it really costs to run.

Which one fits you?

Admiral installs both. We steer most people toward gas because most people heat a pool the first way: now and then, and on short notice.

What a new heater costs installed

Replacing a pool heater in Houston typically runs $3,500 to $6,500 installed. That range covers gas heaters and heat pumps alike, and where you land in it depends on the type and the size of the unit.

That is the price to replace a heater you already have. A first-time install can need a gas line or an electrical circuit run to the equipment, so that one is quoted at a consult.

What it really costs to run in Houston

The usual claim is that a heat pump costs a fraction of what gas does to run. That is true where gas is expensive. It is not true in Houston, where CenterPoint gas is cheap enough to nearly close the gap.

A heat pump's low hourly cost comes with a catch: it has to run many more hours to do the same job. That is why the cost per heat-up ends up so close.

We don't publish a "keep it at 80°F all month" figure. That number swings with wind, evaporation, your set point, and whether the pool is covered, and any single figure would be a guess.

How fast each one heats

Speed is where the two are furthest apart.

• Gas. A 400,000 BTU gas heater raises an 18,000-gallon pool about 2.2°F an hour. A 15°F rise takes about 7 hours.
• Heat pump. Common residential models manage 0.4°F to 1°F an hour in the same pool. The same 15°F rise takes 15 hours or more.

Those rates count only the heat going into the water. On a cool, breezy day a slow heater loses ground to the air while it works, which widens the gap.

Heat pumps in a Houston winter

A heat pump pulls its heat from the outside air, so it does less as the air cools. The Department of Energy puts the efficient range at above 45 to 50°F. One common 100,000 BTU model is rated at 61,000 BTU when the air is 50°F, which is 39% less heat.

Houston winters are mild by day and cool at night:

• Bush Airport averages 92 nights below 50°F from November through March.
• The normal January high is still 63.8°F.
• Hard freezes are uncommon: about 10 days a year at or below 32°F.

So a heat pump run on a winter afternoon is usually working in air it likes. One asked to hold temperature overnight in December or January will often be working in the 40s, with less output and lower efficiency. A gas heater is unaffected.

If a freeze is on the way, heating is not the priority. See winter pool care in Houston for what to do below 35°F.

How long they last on the Gulf Coast

In normal Houston conditions, with the water kept in balance and the unit serviced:

• Gas heater: 7 to 10 years.
• Heat pump: 10 to 15 years.

Manufacturer warranties are shorter than that, and both numbers drop when chemistry or placement is neglected. What protects either type:

• Keep the water balanced. Out-of-range water corrodes or scales the heat exchanger. Heater manuals call for a pH of 7.4 to 7.6.
• Put the chlorinator after the heater, with a check valve between them, and never put chlorine tablets in the skimmer. Both send concentrated chlorine through the heater.
• Keep sprinklers off the unit. On a heat pump, that includes the outdoor coil.
• Saltwater pools are fine with either type when salt and chemistry stay in range. Pool heat pumps use a titanium heat exchanger for that reason.
• On open water in Galveston or along the bay, salt spray shortens the life of the outdoor unit, and manufacturers exclude salt-spray damage from warranty.

For repair-or-replace decisions on a heater you already own, see pool repair costs in Houston.

What size heater you need

Gas heaters for homes run from about 175,000 to 400,000 BTU. The right size depends on the pool's surface area and volume, whether there is a spa, how fast you want it warm, and how exposed the yard is to wind.

An undersized heater runs longer, heats slower, and struggles on a cold day. We size it at the consult, from your pool, rather than from a chart.

Is a pool heater worth it in Houston?

It depends on how you swim, not on the weather. Houston pools are comfortable without help for much of the summer. A heater buys the edges: warm spring and fall weekends, mild winter afternoons, and a spa you can use all year.

If that is a handful of weekends, the running cost is small: about $27 a heat-up on gas. The real cost is the heater itself, at $3,500 to $6,500 installed. If you would never plan a swim around the heater, skip it.

Frequently asked questions

Is a pool heater worth it in Houston?

For owners who swim on spring and fall weekends, on mild winter days, or who have a spa, yes. One 15°F heat-up of an 18,000-gallon pool costs about $27 on gas at November 2026 rates. If you only swim in midsummer, you can skip it.

How much does it cost to replace a pool heater in Houston?

Replacing a pool heater in Houston typically costs $3,500 to $6,500 installed, for a gas heater or a heat pump. Where you land in that range depends on the type and size. A first-time install is quoted at a consult.

Which is cheaper to run in Houston, gas or a heat pump?

A heat pump, but not by much. Raising an 18,000-gallon pool 15°F costs about $21 to $26 on a heat pump and about $27 on gas, at CenterPoint gas rates and the Texas average electric rate as of November 2026.

How much does it cost to heat a pool in Houston?

About $27 for one 15°F heat-up of an 18,000-gallon pool on gas, or about $109 for four of them in a month. A pool cover cuts heating costs by 50 to 70%, according to the U.S. Department of Energy.

Do heat pumps work in winter in Houston?

Yes, with less output on cold nights. Heat pumps lose efficiency below about 50°F, and Bush Airport averages 92 nights below 50°F from November through March. The normal January high is still 63.8°F, so afternoons are usually fine.

How fast does a gas heater heat a pool?

A 400,000 BTU gas heater raises an 18,000-gallon pool about 2.2°F an hour, so a 15°F rise takes about 7 hours. A heat pump usually manages under 1°F an hour.

Is gas or a heat pump better for a spa?

Gas. A spa is heated on demand and needs to get hot quickly, which is what a gas heater does best.

What size pool heater do I need?

Residential gas heaters run from about 175,000 to 400,000 BTU. The right size depends on your pool's surface area and volume, whether it has a spa, and how fast you want it warm, so we size it at a consult.

Will a saltwater pool damage a pool heater?

Not if the salt level and water chemistry stay in range. Out-of-balance water and chlorine tablets in the skimmer are the usual causes of heat exchanger damage.

How long do pool heaters last in Houston?

In normal Houston conditions, a gas heater lasts 7 to 10 years and a heat pump 10 to 15, with the water kept balanced and the unit serviced. Neglected chemistry or a wet, salty location shortens both.

Does a pool cover really cut the heating bill?

Yes. The U.S. Department of Energy puts the saving at 50 to 70% of heating costs, because most of a pool's heat is lost through evaporation.

Pool heater installation in Houston: get a quote

Tell us about your pool and how you use it, and we'll recommend a heater and quote the install. Installs are done by Admiral's RAI-licensed installers. Request a heater quote or call (281) 624-6191.

Already have a heater that isn't working? That is a repair question first: start with pool heater repair. The diagnosis visit is $125, credited toward the repair if you go ahead, and it's usually within 48 hours.

For the wider picture of what a pool costs to keep, see what pool service costs in Houston.