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5 signs your pool heater needs repair

A pool heater rarely fails all at once, so catching the early warning signs can save you a cold pool and a bigger repair bill down the line.

A failing heater rarely quits all at once. It usually starts with smaller hints, a little less heat, a longer run time, an odd noise, before it finally leaves you with a cold pool on the wrong day. The good news is that most of those hints are easy to spot once you know what to look for, and catching them early often means a smaller, cheaper repair instead of a full replacement. Here are five of the most common signs that your pool heater or heat pump needs attention before the first cold snap.

What to watch for

The five signs

If you notice any of these, it is worth having the heater looked at.

1. No heat, or the water never reaches the set temperature

The most obvious sign is a heater that runs but never warms the water to where you set it, or never fires at all. This can point to a faulty thermostat or temperature sensor, a gas valve that is not opening fully, a unit that is undersized for your pool, or scale buildup inside the heat exchanger that is choking how much heat actually reaches the water.

2. The heater throws an error code or will not ignite

Modern heaters and heat pumps display fault codes for a reason, and a unit that will not ignite is trying to tell you something. The cause is often a failed ignitor or flame sensor, a control board problem, or an underlying gas or water flow issue that is locking the heater out for safety. The code itself is a clue, but reading it correctly and fixing the root cause is where a proper diagnosis pays off.

3. Short cycling: it turns on and off rapidly without heating

If the heater keeps firing up and shutting back down in quick bursts without ever really warming the water, that is short cycling. It is commonly caused by low water flow, a dirty filter, or a pressure switch or sensor fault that keeps interrupting the heating cycle. Beyond the cold water, short cycling puts extra wear on the unit, so it should not be left to run that way.

4. Strange noises, leaks, rust or soot at the heater

Rumbling, banging or whistling sounds, water pooling under the unit, rust streaks or soot around the burner are all signs that something is wrong inside. These can come from scale, a leaking heat exchanger or poor combustion. Treat soot or a gas smell as urgent: shut the heater off and call right away rather than letting it keep running.

5. Slow heating or a jump in your gas or electric bill

If the pool takes much longer to warm up than it used to, or your gas or electric bill climbs without any change in how you use the pool, the heater is working harder than it should. That extra effort usually traces back to scale buildup, a failing component or a unit that is straining to do its job. Catching it early can turn a rising bill back into a normal one.

Before you call

What you can check first

A few of these are quick to rule out on your own before anything more involved.

  • Is the filter clean and is water flowing properly to the heater?
  • Is the breaker for the heater on and not tripped?
  • Is the gas supply on?
  • Is the thermostat set above the current water temperature?

If those check out and the heater still will not behave, leave the gas and electrical components to a professional. Those are the parts where a wrong move can be dangerous, and they are exactly where we come in.

Why it matters

Heaters mix gas, water and electronics

A pool heater is one of the trickier pieces of equipment on the pad because it brings together gas, water and electronics in one unit. The control and power side, the sensors, the ignitor and the board, is exactly where a licensed-electrician background helps make sense of what is actually failing. McEwan Pools is owner-operated by a licensed electrician with 25+ years of experience, and we service all major brands, including Pentair, Jandy, Hayward and Intermatic, across natural gas, propane and electric heat pumps.

Heater questions

Pool heater FAQs

Should I repair or replace my pool heater?

It depends on the age of the unit and the problem. Many heater issues are a sensor, ignitor, control board or gas valve that can be repaired for far less than a replacement. We diagnose the real cause first and tell you honestly when a repair makes sense and when a new unit is the better value.

Why won't my pool heater turn on?

Common reasons include a dirty filter or low water flow, a tripped breaker, a failed ignitor or sensor, a gas supply issue or a control board fault. Some are simple, some are electrical, which is exactly where a licensed-electrician background helps.

What brands of pool heaters do you repair?

All major brands, including Pentair, Jandy and Hayward, for natural gas, propane and electric heat pumps.

How do I get my heater looked at?

Call (817) 793-2977. Start with a full site evaluation for $80, which is deducted from your repair bill when you move forward, so you get a real diagnosis and a clear quote before any work.

Get your heater diagnosed before it fails

If your heater is showing any of these signs, the sooner it is looked at, the better the chance of a simple repair instead of a cold pool and a bigger bill. We service all major brands across gas, propane and electric heat pumps.

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