Nest Thermostat Short Cycling AC

Feeling like an overprotective mom worrying if your nursery’s temp is just right for your baby? I feel you! As moms, keeping our homes at just the right temperature for our families is a priority.

And there’s nothing more frustrating than an AC that won’t cooperate.

If your Nest thermostat is making your air conditioner short cycle on and off, I know how irritating that is. But take a deep breath—there are some simple troubleshooting tricks we can try to fix this.

In this handy guide, I’ll walk through the common causes plus solutions to get your system running just right.

Nest Thermostat Short Cycling AC

nest thermostat short cycling ac

What is Short Cycling Anyway?

Basically, short cycling is when your AC turns on and off repeatedly in short spurts instead of running long enough to properly cool the space. You might notice that:

  • Turns on and off frequently.
  • Doesn’t effectively cool or dehumidify the air.
  • Cools intermittently rather than continually.

This inefficient on and off process strains your HVAC system unnecessarily. It can also jack up your energy bills more than needed. No thanks! Let’s stop this short cycling stat.

Top Causes of Nest Short Cycling Issues

Before we dig into fixes, it helps to understand what’s causing this annoying issue in the first place. Here are the most common reasons your Nest is making your AC short cycle:

Low Power or Dead Nest Batteries:

Like any battery-powered device, Nests can short cycle HVAC systems when their batteries run down. Time for fresh ones!

Faulty or Outdated Wiring:

If the wires connecting your Nest to your HVAC system are faulty, damaged, or just old, this can cause electrical issues triggering short cycling.

Incorrect Sizing An oversized AC unit that’s too powerful for your home can result in the system quickly reaching temp and then switching back off again.

Dirty Filters and Coils When air filters or HVAC coils get clogged with dust and grime, this restricts airflow and throws off the heating/cooling process in a way that leads to short cycling.

Refrigerant Issues If refrigerant levels are too low, it reduces your AC’s cooling capabilities leading it to cycle on and off repeatedly struggling to reach the right temperature.

Technical Glitches Sometimes good old-fashioned restarts, resets, and firmware updates are needed if tech gremlins sneak into your Nest’s software controls.

Easy Ways to Stop Your Nest From Short Cycling Your AC

Now that we know some of the culprits that cause this thermostat trouble, let’s go through solutions you can try at home before calling in the pros:

Refresh Those Nest Batteries

Let’s knock out the easiest fix first. If your Nest batteries are more than 3 years old, swap them for fresh ones:

  1. Turn the power to the thermostat off.
  2. Remove old AAA batteries.
  3. Add 2 new alkaline AAA batteries.
  4. Power the thermostat back on.

Give those new batteries a chance to fully charge and see if that stops the short cycling. Fingers crossed!

Double Check HVAC Connections

While you have the Nest off the wall, inspect all wiring connections leading from the thermostat to your HVAC system. Faulty wiring is often the culprit behind fussy thermostat troubles, so it pays to check for:

  • Loose connections.
  • Exposed copper wires.
  • Signs of corrosion.

If wires are damaged or connections seem loose, try securing everything tightly or replacing bad wires. This may help deliver smooth electrical current to prevent short cycles.

Try Resetting Your Nest

Before you panic and call the HVAC repair guy, try rebooting your Nest first—yes, just like restarting your computer! Resetting often clears up minor software glitches causing issues:

  1. Go into your Nest’s Settings.
  2. Choose the “Restart” or “Reset” option.
  3. Confirm to restart/reset the device.

Give your Nest a few minutes to reboot and refresh its systems. Then try it out to see if your AC runs normally without short cycling.

Clear Out HVAC Filters and Coils

Here’s an easy DIY fix to try next. Dust and debris trapped in your HVAC system can block airflow and throw off your Nest’s temperature balancing act.

Carefully remove filters and use a gentle brush attachment on your vacuum to clear any built-up gunk. You can also sanitize the filters or replace them if they’re really grimy.

For harder-to-reach evaporator coils, you can try a DIY cleaning if they’re accessible. Or better yet, leave that dirty work to the pros! Most HVAC companies offer annual maintenance plans to keep your whole system tip-top.

Update Your Thermostat Firmware

Like any smart gadget these days, Nest issues periodic software updates with handy upgrades and bug fixes. If your thermostat seems glitchy, make sure yours has the latest firmware:

  1. Check for firmware update alerts in your Nest app.
  2. Follow the prompts to download and install new software.

This refreshes outdated coding that could be contributing to operating issues like short cycling. Updating also helps optimize performance and unlock any new features.

Consider AC Unit Sizing

While certainly not a DIY fix, incorrectly sized HVAC systems can also cause short cycling head scratchers. If your unit seems to be constantly struggling to heat or cool your home efficiently, the capacity could be off.

Consult an HVAC pro to determine ideal sizing based on technical factors like:

  • Square footage of your home.
  • Number of rooms.
  • Typical occupancy.
  • Historical energy use.

A unit that’s perfectly matched to your space will operate smoothly without overstraining itself into short cycles.

When to Call the Pros?

Of course, if you still have Nest short cycling problems after trying the troubleshooting fixes, it may be time to loop in the pros. Difficult-to-spot issues like refrigerant leaks or bigger mechanical malfunctions usually require expert equipment and know-how.

Signs you need pro help:

  • Very old AC unit
  • Visible damage to equipment
  • Strange noises during the operation
  • Refrigerant likely needs recharging
  • Thermostat swaps didn’t fix it

Most reputable HVAC companies offer maintenance club subscriptions to keep your system operating optimally year-round. Choose one that specializes in Nest products.

FAQs about Nest thermostats short cycling AC units:

  1. Does a Nest thermostat draw a lot of power to cause short cycling?

No, Nest thermostats are designed to conserve power. However faulty wiring or dying batteries can drain power, leading to cycling issues.

  1. Can using the wrong C-wire adapter make a Nest thermostat short cycle?

Yes, incorrect or faulty C-wire adapters can disrupt power delivery and cause short cycling problems.

  1. My Nest temperature schedule seems off – could this trigger short cycling?

Possibly. An inefficient or faulty schedule that makes your system work extra hard can contribute to short cycling in some cases.

  1. I have a zoning system – will that impact Nest thermostat performance?

It can. Zoned HVAC systems are complex, so be sure your Nest professional properly installs and programs it to work smoothly with your zones.

  1. Can extreme weather or temperatures cause a Nest thermostat to short cycle?

Yes. Very hot or cold outdoor temps put extra strain on an HVAC system. If it struggles to keep up, short cycling can occur.

  1. I have a heat pump system – is that compatible with the Nest?

Nest thermostats are compatible with most heat pumps. However incorrect installation or setup for a heat pump can disrupt operation and lead to issues like short cycling.

  1. My home is newly constructed – is short cycling common with new AC systems?

It can be. Proper sizing and setup are imperative for new construction homes to prevent overstraining the new AC system.

  1. How do I know if my units are short cycling because they’re too small vs. too large?

Oversized units will short cycle since they reach temp too quickly and then overcompensate. Undersized units run too long with little effect. A pro can best assess proper sizing.

  1. Can frequent temperature adjustments cause a Nest thermostat to short cycle?

It’s unlikely, but constantly manually overriding the Nest temp settings can in some cases put extra strain leading to cycling issues.

  1. How often should HVAC filters be changed out to prevent short cycling?

As a general rule of thumb, aim to replace filters about every 3 months. Clogged filters are a major – yet preventable – culprit behind AC short cycling.

Also Check:

The Bottom Line

Having your thermostat continually short cycle your HVAC system is no fun at all. It strains your equipment, spikes energy use, and keeps your home uncomfortable.

If rebooting your Nest and some DIY fixes don’t solve the issue, call in professional help before things get worse. Stay cool!