Why Is My Heat Pump Not Turning On? A Florida Tech Answers

November 03, 2020

AC Troubleshooting

If you’ve noticed that your heat pump hasn’t kicked on in quite a while, you’re probably wondering what’s going on with your system.

We wish we had one simple answer for you as to why your heat pump won’t turn on, but unfortunately, the only way to determine exactly what the issue is is to have a professional assess your heat pump and determine the problem.

However, we can provide you with a few ideas about what might be preventing your heat pump from turning on, and a few of those issues you can fix yourself.

Your heat pump may not be turning on if:

  1. Your thermostat is on the wrong settings
  2. The condensate drain pan has overflowed
  3. The circuit breaker has tripped
  4. Key components of your system are faulty or damaged

Throughout this blog, we’ll walk you through these issues and let you know what you can do to fix them or if you need a professional’s help.

Rather just have a professional come out and take a look at your heat pump? We get it! Learn more about the heat pump services we offer or schedule a repair with us!

Issue #1: The thermostat is on the wrong settings

If your heat pump isn't turning on, the first thing we’d suggest is to take a look at your thermostat settings.

You have three options: HEAT, COOL or OFF.

On Vs Auto 3

During the winter, your heat pump should be set to HEAT, and during the summer, your heat pump should be set to COOL.

If it's winter, and your heat pump has accidentally been bumped to COOL (or the setting was never changed between seasons), this could be a reason why your heat pump is not turning on. The same logic applies to your heat pump being set to HEAT during summer.

And obviously, if your thermostat is set to OFF, it also won’t turn on.

If you’ve checked your thermostat and your heat pump is on the right setting (COOL for summer, HEAT for winter), but your heat pump still won’t turn on, keep reading.

Issue #2: Condensate drain pan has overflowed

While the main job of your heat pump is to cool your home, its secondary job is to dehumidify your home.

Your heat pump does this by drawing warm air from your home in and blowing that air over a part called an evaporator coil. The condensation from the air gathers on the coil and is collected in a drain pan, which sits underneath the evaporator coil.

The drain pan collects the condensation and then moves it out of your home via the condensate drain line.

If your drain pan gets too full, it may trigger the float switch, which will turn off your heat pump to prevent any damage.

If this is the case, you may also notice some water pooling around the bottom of your heat pump in addition to your heat pump not turning on.

Typically, your drain pan will overflow for two reasons:

  • Your evaporator coil is frozen
  • There’s a clog in the condensate drain line

Evaporator coil is frozen:

If there isn’t adequate airflow to your evaporator coil or your refrigerant levels are low, there won’t be enough heat transfer at your evaporator coil which can cause it to freeze.

Note: A frozen evaporator coil will only happen when your heat pump is in cooling mode.

Eventually, that ice will start to melt and can overflow your drain pan, causing the float switch to turn your heat pump off.

If you think your evaporator coil may be frozen, you can start by replacing your air filter. If this doesn’t fix the problem, you likely have a refrigerant leak and will need to reach out to a professional for help.

Clog in the condensate drain line:

Evaporator Coil Drain Pan

Another factor that can cause your drain pan to overflow is if there is a clog in the condensate drain line. This can back up the line, causing the pan to overflow and trigger the float switch.

The good news is, if you have a minor condensate clog, you can usually unclog it yourself.

Start by…

1. Locating your condensate drain line. It’s usually a white PVC pipe and will be located near your outdoor unit.

Condensate Drain Pipe

2. Using a shop vac, create an airtight connection between the end of the drain line and the shop vac.

3. Turn the shop vac on for 1-2 minutes.

If your heat pump starts working again, problem solved! If not, the clog could be too-high up in your line, too extensive or there could be another issue with your heat pump that you’ll need a professional’s help with.

Issue #3: Circuit breaker has tripped

Another possible reason that your heat pump is not turning on is that your circuit breaker has tripped. If there is no electricity going to your system, it won’t be able to turn on.

To check this, head to the circuit board and check to see if the breaker labeled heat pump or AC has slipped to the neutral position.

If it has, turn the breaker off for 30 seconds and then flip it back to ON.

If the breaker trips again, you’ll want to reach out to a professional for help. There could be a variety of reasons your heat pump is causing the breaker to trip, and you could cause significant damage to your home’s electric or your heat pump by resetting the circuit breaker again.

Issue #4: Key parts of your heat pump are damaged

Your heat pump may not be turning on because a key component of your system may be damaged or faulty. Typically, if your heat pump won't turn on because of a damaged or faulty part, it's either a problem with the capacitor or the reversing valve. We'll look at each of these parts below.

Capacitor

If you hear a clicking noise indicating that your heat pump is trying to turn on but can't, the capacitor is probably the issue. The capacitor is part of your outdoor heat pump unit, and it's responsible for “jump starting” your outdoor unit. If it's damaged or faulty, your heat pump will attempt to start up, but without that extra surge of energy, will fail to do so. If you think that you have a damaged or faulty capacitor, you'll need a professional to come take a look and probably replace your capacitor.

Reversing valve

The reversing valve is a part of your heat pump that's responsible for switching your heat pump from cooling mode to heating mode and vice versa.

If there's an issue with your reversing valve, your heat pump may not turn on in either cooling or heating mode.

Our suggestion would be to play with your thermostat to determine if the reversing valve is the issue. If it's fall or winter, lower your thermostat and see if your AC kicks in. If your heat pump will cool but not heat, there's probably a reversing valve issue.

If it's spring or summer, try raising the thermostat to see if heating mode kicks in. If it does, but your heat pump won’t cool, the same logic applies: there’s likely an issue with the reversing valve.

If you think the reversing valve is the issue, you'll need professional help. Depending on the level of damage, the reversing valve may need to be replaced completely.

Still having issues with your heat pump? Contact Red Cap!

If you’ve tried the DIY fixes we mentioned above but still can’t get your heat pump to turn on (or you think you may be experiencing one of the issues only a professional can fix), reach out to us! Hundreds of Southwest Florida homeowners trust us to repair their heat pumps every year, and we’d be happy to earn your trust too.

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