Pool Heater Replacement Parts
Replacement Igniters, Control Boards, Sensors & Kits for Pool & Spa Heaters
98 products
98 products
Pool Heater Replacement Parts In-Stock Ready to Ship
Aqua Pool Supply stocks replacement parts for Pentair MasterTemp and Max-E-Therm pool and spa heaters, along with components for other major heater brands. From igniters and control boards to sensors, switches, and manifold kits, these parts let you fix a heater fault and get back to warm water without replacing the entire unit. Most MasterTemp and Max-E-Therm heaters share the same platform, so many parts cross over between the two.
Common Pool Heater Parts
Heater components generally fall into three groups, depending on which system has failed:
Ignition & Electrical
The parts that start and control the heater: the igniter and gasket kit, ignition control module, control board, transformer, wiring harness, and the membrane pad on the control panel. These are the most common culprits when a heater won't fire or the display behaves erratically.
Sensors & Safety Switches
The components that monitor the heater and shut it down if something is wrong: the thermistor (temperature sensor), high limit switch, air flow switch, stack flue sensor, and water pressure switch. A faulty sensor often shows up as an error code or a heater that starts and then quickly stops.
Water Flow & Gas Components
The parts that move water and fuel through the heater: the heat exchanger or tube sheet coil assembly, manifold and O-ring kits, thermal regulator, gas valve, flameholder, and blower. Leaks, weak heating, and combustion faults usually trace back to this group.
Common Heater Problems and the Parts That Fix Them
If you're trying to narrow down a fault, these are the typical pairings:
- Heater won't ignite. Often the igniter, ignition control module, or gas supply.
- Starts then shuts off. Frequently a sensor, the high limit switch, or a flow or pressure issue.
- Error code on the display. Usually a sensor (thermistor or stack flue sensor) or the control board.
- Leaking water. Commonly the manifold O-rings, header, or a failing heat exchanger.
- Weak or no heat. Often the thermal regulator, gas valve, or restricted water flow.
These are starting points, not a substitute for diagnosis. Because pool heaters involve both gas and electricity, we strongly recommend having a qualified, licensed professional handle gas and electrical repairs to keep your equipment safe and your warranty intact.
Finding the Right Part
Heater parts are model-specific, so the fastest way to order correctly is to check the rating plate on your heater for the exact model and serial number. Pentair MasterTemp and Sta-Rite Max-E-Therm heaters share many of the same components, but BTU size and the year of manufacture can change which version you need. If you're unsure which part matches your heater, reach out and we'll help you confirm the right one before you buy.
Need a New Heater Instead?
If a repair no longer makes sense, we carry complete heating systems too. Browse Pentair MasterTemp gas heaters for fast, on-demand heating, or Pentair UltraTemp heat pumps for energy-efficient operation. You can also compare every option in our full pool heaters and heat pumps collection.
Prefer to grab the part in person? Aqua Pool Supply offers same-day pickup at our Phoenix, AZ and Las Vegas, NV locations. Order online or stop in and we'll help you find the component you need.
Pool Heater Parts FAQs
Do Pentair MasterTemp and Max-E-Therm heaters use the same parts?
In most cases, yes. The Pentair MasterTemp and Sta-Rite Max-E-Therm are built on the same heater platform, so igniters, control boards, sensors, and many other components cross over between the two. Always confirm the part against your specific model and BTU size, since some versions changed over the years.
Why won't my pool heater ignite?
The most common causes are a worn igniter, a failing ignition control module, or an interruption in the gas supply. Sensors and safety switches can also prevent ignition if they detect a problem. Because diagnosing and repairing ignition faults involves gas and electrical components, this work is best left to a licensed professional.
Why does my heater turn on and then shut off?
Short-cycling like this usually points to a safety device doing its job: a high limit switch, a temperature sensor, or a flow or pressure problem telling the heater to stop. Low water flow, a dirty filter, or a faulty water pressure switch are common triggers. A technician can confirm whether the part or the flow condition is the root cause.
Can I replace heater parts myself?
Some external components are straightforward for a handy owner, but anything involving the gas train, combustion, or electrical wiring should be handled by a qualified, licensed professional. Improper repairs can be dangerous and may void your warranty. When in doubt, have a pro confirm the diagnosis and complete the repair.
How do I find the exact part for my heater?
Check the rating plate on your heater for the model and serial number, then match the part to that model and its BTU size. If you're not certain which version you need, contact us with your heater details and we'll help you confirm the correct part before you order.