Pool Heater Repair vs. Replace: What Each Costs and How to Decide

Pool heater repair costs in the DMV usually land between $175 and $600 for the common failures, with major heat-pump work running $500 to $1,200 or more and a heat exchanger replacement running $800 to $1,800. A new heater installed is $5,000 to $10,000 for gas or a heat pump, and $3,000 to $6,000 for solar. A diagnostic visit is $125 to $195, and it is almost always worth paying for before you decide anything.

The reason those numbers matter so much is the gap between them. Most heater problems are a few-hundred-dollar part. A few are half the price of a new unit. Knowing which one you are looking at — before you authorize work — is the difference between a reasonable repair and money spent on a heater that fails again next season.

Pool Heater Repair Costs by Failure Type

These are Beltway Pools' typical service ranges across Northern Virginia, Maryland, and DC. Final pricing depends on brand, part availability, and access.

Service	Typical cost	What it usually is
Diagnostic visit	$125 – $195	Gas pressure testing, flow rate check, electrical inspection, fault-code readout.
Igniter or thermocouple replacement	$175 – $350	The most common gas-heater failure. Heater clicks but will not fire.
Gas valve replacement	$300 – $600	Inconsistent ignition or no gas delivery despite good supply pressure.
Heat pump compressor or refrigerant work	$500 – $1,200+	Heat pump runs but does not transfer heat. Refrigerant service requires licensed technicians.
Heat exchanger replacement	$800 – $1,800	Corroded or leaking exchanger. The decision point between repair and replacement.
New heater, installed	$5,000 – $10,000 (gas or heat pump) $3,000 – $6,000 (solar)	Includes the unit, installation, and connection to existing gas, electrical, or plumbing.

Pressure switches and flow sensors deserve a separate mention: they are inexpensive parts that produce the alarming symptom of a heater that refuses to fire while everything else looks fine. They are usually a same-day fix, and they are the reason a diagnostic visit pays for itself so often.

The Repairs That Are Almost Always Worth It

If the diagnosis lands on any of these, repair without much hesitation — assuming the heater is not already near the end of its life:

• Igniter, thermocouple, or pilot assembly. Consumable ignition components. Replacing them is normal maintenance on a gas heater, not a sign the unit is dying.
• Pressure switch or flow sensor. Cheap, common, and frequently misdiagnosed as a dead heater.
• Gas valve. A real part cost, but far below replacement, and a new valve on an otherwise sound heater buys years.
• Control board or fault-code issues on a newer unit. Modern heaters report specific codes. A board on a five-year-old heater is worth replacing; the same board on a fifteen-year-old heater usually is not.
• Low gas pressure at the heater. Often not the heater's fault at all — it can be supply-side, which means the fix is upstream.

The Findings That Point to Replacement

• A corroded or leaking heat exchanger. This is the pivot. At $800 to $1,800, an exchanger is a real fraction of a new heater — and if chemistry caused the corrosion, the rest of the unit's internals have been living in the same conditions. On a heater past roughly ten years, replacement is usually the better spend.
• Compressor failure on an older heat pump. Heat pumps last 10 to 15 years. A compressor at year twelve is replacing the most expensive component in a unit that is nearly done.
• Repeat failures in a single season. Two or three service calls in one summer is the market telling you something. Add the invoices before authorizing a fourth.
• Discontinued parts. Older heaters eventually lose parts support. Once a specific board or exchanger cannot be sourced, the decision is made for you.
• A repair quote approaching half the price of a new heater. The standard rule of thumb, and it holds up well for heaters specifically because efficiency has improved meaningfully over the last decade.

Water Chemistry Is Usually the Real Culprit

Heat exchangers do not corrode randomly. Low pH, low alkalinity, and high chlorine concentrations attack the exchanger's metal from the inside, and the damage accumulates quietly over seasons. Saltwater pools add another consideration if the exchanger material is not appropriate for the water.

This matters commercially: if you replace a heater without fixing the chemistry that killed the last one, you have bought the same problem with a longer runway. Any honest heater replacement conversation should include a look at your water balance — our guide to how to balance pool chemicals covers the ranges that protect equipment, not just the ones that feel comfortable to swim in.

If You Are Replacing: Same Type, or Switch?

A replacement is the one moment when switching heater types costs almost nothing extra in labor, so it is worth a real look:

• Gas ($5,000 – $10,000 installed). Heats in hours regardless of air temperature. The right answer if you swim occasionally, want the pool warm on a specific weekend, or want to extend into cool October evenings. Higher cost per BTU to run.
• Heat pump ($5,000 – $10,000 installed). Moves ambient heat instead of burning fuel to make it — the U.S. Department of Energy rates heat-pump pool heaters at a coefficient of performance of 3.0 to 7.0, meaning three to seven times more heat delivered than energy consumed. That efficiency edge does not convert one-for-one into dollars, because electricity costs more per BTU than natural gas, but in warm weather a heat pump is normally the cheaper unit to run, and the margin is widest against propane. It heats slowly, and the DOE notes efficiency falls off once outdoor air drops below about 50°F — which in the DMV means it does less for you in late October than a gas heater would.
• Solar ($3,000 – $6,000 installed). No operating cost at all, minimal maintenance, but it is weather-dependent and needs adequate roof or ground area. Best as a season-extender rather than an on-demand heater.

Our comparison of heat pump vs. gas pool heaters in the DMV goes deeper on the operating-cost math and which use pattern each one suits.

One more practical factor: Beltway Pools is an authorized Jandy warranty service center and installs and services Pentair, Jandy, Hayward, Raypak, Rheem, and Lochinvar. If your existing heater is still under manufacturer warranty, an authorized repair may cost you far less than the ranges above — always worth checking the age and warranty status before assuming you are paying full price.

Why Timing Changes the Repair-or-Replace Answer

A heater is the one piece of pool equipment where the calendar changes the answer.

The DMV's heated-swimming payoff comes in the shoulder seasons: September and early October on the back end, late April and May on the front. That is exactly when a heater earns its cost. If your heater has been marginal all summer, you still have several usable weeks — enough that a $175 to $600 repair may return real value this season rather than none.

Replacement runs the other way. A new heater installed at the tail end of the season gets you a few weeks of use; the same heater installed next April gets you a full season. So the timing logic splits: repair now if the fix is small and the heater has life in it; schedule the replacement for spring if the number is large — and either way, get the diagnosis while the pool is still open and the heater can be run through a full heat cycle. Once the pool is winterized, nobody can test it.

That also means the heater deserves a place on your closing checklist. A heater that has been struggling should be diagnosed before pool closing, not discovered at opening — and if you are already working through late-season equipment issues, our guide to troubleshooting common pool equipment problems covers the symptoms that are worth a service call.

Bottom Line: Repair or Replace?

Pay the $125 to $195 for a diagnosis first — it is the cheapest information you will buy in this process. If the answer is an igniter, thermocouple, pressure switch, flow sensor, or gas valve, repair it: $175 to $600 on a heater with life left is good money. If the answer is a corroded heat exchanger ($800 to $1,800), a compressor on an older heat pump, discontinued parts, or a third service call in one season, price a replacement instead — $5,000 to $10,000 installed for gas or a heat pump, $3,000 to $6,000 for solar — and fix the water chemistry that shortened the last one's life.

Beltway Pools diagnoses, repairs, and replaces gas, heat pump, and solar pool heaters across Northern Virginia, Maryland, and DC, and we are an authorized Jandy warranty service center. Book pool heater repair or replacement, compare the numbers against our pool service cost ranges, or request a quote and we will tell you honestly which side of the line your heater is on.