Advice about pool heaters tends to arrive secondhand, from a neighbor with a different model, a forum thread about another climate or a video that skips the safety steps. That is a poor basis for decisions about gas, power and plumbing. This page sticks to what applies to most residential heaters, for owners in Edmonton who searched for “Jandy pool heater repair”, and it explains pool heater repair clearly enough that you can judge any advice you get.

What is the heat exchanger in a pool heater?
The heat exchanger is the part that transfers heat into the pool water, and it is the heart of every heater. In gas units it is a set of finned tubes sitting above the burners. In heat pumps it is a corrosion-resistant coil or tube bundle that the hot refrigerant gas passes around. In electric heaters the elements play the same role. Because pool water, chemicals and heat all meet here, it is the component most affected by poor water balance. Scale, corrosion and freezing can each damage it, so a heater often lives only as long as its exchanger does.
Why does the heater show a different temperature than the pool?
The heater and your hand are not measuring the same thing. Most heaters read the temperature of water entering the unit, which can differ from the water at the far end of the pool, especially while the pump is off or the sun is warming the surface. A sensor that has drifted, been fouled by scale or been installed in the wrong spot can also give misleading numbers. Compare the display with a floating or handheld thermometer after the pump has run for a while. A steady gap of several degrees is worth reporting to the technician, because a wrong reading makes the heater stop early or run too long.
Why does a gas pool heater try to light and then shut down?
We listen and watch the sequence. A fan starts, an igniter glows or sparks, and the gas valve should click open. If we hear sparking but see no flame, we suspect gas delivery or the burner. If the igniter never heats, the igniter or its power is at fault. If a flame appears for a second and then drops, the flame sensor or its grounding is the usual suspect. Because each result leads to different repairs, guessing at parts rarely works. Meanwhile, you can confirm that a propane tank has fuel in it, which costs nothing to check.
Is it safe to run a pool heater that has a fault?
Our rule is simple: if it involves fuel, fire, power or water in the wrong place, shut it down. If it is only about comfort, such as a pool that heats slowly, the heater can often keep running until we arrive. The danger in carrying on is that safety devices can mask a worsening problem. A heater that restarts after each reset is still reporting trouble, and ignoring it may damage the exchanger or board. When in doubt, turn it off, note what you saw and call us with the details.
Could the fuel supply be the problem instead of the heater?
Sometimes, yes. A gas heater cannot run without fuel reaching the burner, so a closed shutoff valve, an interrupted supply or a nearly empty propane tank can look exactly like a broken heater. If you use propane, check the tank gauge. Confirm that other gas appliances at your home work normally; if they do not, the issue sits with the supply, and your gas utility or propane provider can help. Do not open the heater cabinet, loosen fittings or try to adjust valves, and if you smell gas, leave the area and call from a safe distance. A technician can test supply pressure and settings once you have ruled out the simple causes.
How does scale damage a pool heater?
Scale is a slow problem with a quick give-away: the heater gets noisy and pool temperatures rise more slowly than before. We confirm it by checking the temperature rise, the pressure drop across the unit and, when the headers are off, the look of the tube interior. Cleaning is done with a proper descaling solution circulated in a controlled way, followed by a thorough rinse, because ordinary household acids can harm the metal. Afterward the pool’s calcium hardness, alkalinity and pH deserve testing, or the crust will simply rebuild over the next season.
Can a pool heater be repaired in one visit?
The honest answer is that diagnosis takes as long as it takes, and the repair itself is usually the shorter part. We arrive with common igniters, sensors, switches and gaskets, so straightforward faults are often finished before we leave. When the failed item is a control board, an exchanger or a model-specific part, we place the order and schedule a return once it arrives, and we tell you how long we expect to wait. Rushing a repair rarely helps, since a missed cause means a callback. A complete test at the end is part of the job, not an extra.
What affects the cost of running a pool heater?
Running cost comes down to how much energy the heater uses and how long it runs. Fuel type and local rates set the baseline, with gas, propane and electricity each priced differently. Heat pumps use less power for the heat they deliver, but their efficiency falls when the air is cold. Pool size, desired temperature, wind, shade, cover use and the length of the heating season set the demand. Heater condition matters as well, since a scaled exchanger or dirty burners waste energy. Your utility bills compared before and after heater use give the most real-world measure.
When is it time to replace a pool heater instead of repairing it?
The decision rests on a few questions. How old is the heater, and how often has it needed repairs? What failed: an inexpensive part, or the heat exchanger or compressor that makes up much of the unit’s value? Are parts still available? Is it efficient and sized correctly for your pool? A single modest repair on a heater that otherwise runs well is usually sensible. Repeated failures, a leaking exchanger, heavy corrosion or a repair that approaches the cost of a new unit all point toward replacement.
Ready to book pool heater repair in Edmonton?
Once you know the work is due, the next step is simple. Tell us a little about your pool heater and the days that suit you, and we will suggest a time that works. Request a quote and the Gas Fireplace Edmonton team will follow up with details.

