Answers to Your Questions About Running Your AC/Heat Pump During the Heat Wave

Our phones are ringing off the hook today with customers calling in with concerns and questions about using their equipment during the Heat Wave. Here is a summary of our answers and helpful tips for you. This email is a public service message and not a sales message.


  • Check and replace (or clean if it’s a ductless system) your system filters – this will help your system breathe and operate easier. NOTE: your system has to breathe through the filter and if it’s dirty or clogged, it makes the system run harder – which can lead to premature failure. 
  • Set your thermostat to 75 degrees on a 90+ degree day (78 degrees when you can tolerate it) – anything lower will make your system work harder than it’s designed to and can lead to system failure. Running it hard one or two days a year is acceptable, but when temperatures are expected to exceed 90+ degrees for extended days on end, setting your thermostat too low will push your system to work on overdrive too long and cause failure.
  • Close your blinds/curtains to help insulate your home – thiscan help lower your indoor temperature.
  • Avoid using heat-generating appliances during the heat of the day (e.g. ovens, stoves, dishwashers, dryers). These appliances make your home cooling system work harder.
  • Use ceiling fans and portable fans to help circulate the air and provide additional comfort.
  • Don’t turn your system on and off – during a heatwave, it’s better to run your AC / Heat Pump at 78 degrees while you out running errands or at work and let it maintain this temperature instead of turning it off while you are gone and then turning it back on again when the home interior exceeds 80+ degrees.
  • Don’t forget your pets! – if they are home unattended, keep your cooling system running to help keep them safe from heat exhaustion. Call your local veterinarian to ask for the temperature needed for your specific pets (some animals are more heat-sensitive than others). A common rule of thumb is 78 degrees.
  • Manage your cooling expectations – most residential cooling systems in our climate are designed to cool a structure down to 75 degrees in a maximum of 90-degree weather. If your system is set to 68 degrees on a 90+ degree day, it’s not a realistic set point to maintain and can harm your system – especially if its older with less capacity to operate on higher temperature days.
  • Turning the temperature down on your thermostat doesn’t make it cool faster, it just makes the system work harder which could lead to failure during a heatwave.
  • Make sure your outdoor unit has adequate airflow – remove stored items/debris and trim shrubs and high grass growing around it – cut it back so there is at least 2-3 feet of space around it. Your system can’t operate well with restricted airflow.
  • On the hottest days, especially if your outdoor unit is older, in full sun without shade, you can run a sprinkler on a light setting near the outdoor unit to help cool down the air around it. It’s ok if some water gets on the outdoor unit (it’s just like rain), just be careful not to leave the sprinkler running all day and night as that can significantly increase your utility bill and waste a lot of precious water.
  • If your system is older than 10+ years, is out of warranty and hasn’t been well maintained (e.g. annual maintenance performed by an HVAC Service Technician), it’s capacity is lower than a newer, well-maintained system and running it hard during a heatwave may likely cause it to fail. If you are concerned about this, the best recommendation we have is to get supplementary cooling (e.g. window units, fans, etc.) or temporarily relocate yourself and your pets to a motel, hotel or cooler climate such as the coast.
  • Get preventative maintenance done by an HVAC Technician to help keep your system operating safely and efficiently to the manufacturer’s specifications.
  • Make sure your home’s attic and floor insulation is up to current code requirements to help insulate your home from outdoor temperatures and help keep the cooling and heating your system provides inside your home. 
Below are Common Trouble Shooting Tips. However, if you keep having issues, or your system fails, please call or text us at 541-747-7445 to schedule a Service Call.


If you see water dripping or draining from your cooling system, here are some general rules of thumb to follow:

  1. If it’s dripping or running from a drain line outside your home, this is generally normal – this is your condensation drain line and during a heatwave with high humidity, you can expect quite a bit of condensation to be draining.
  2. If it’s dripping or running from a unit inside your home or garage, you may have a clogged drain line/pan, a failed condensate pump, an iced-up coil or some other problem and will need to have a Service Technician come out to diagnose and repair it for you. 
  3. If the water is draining in an area that can cause structural damage (e.g. down a wall, onto floors, or through a ceiling) please turn the system off immediately to help stop the water flow and put towels and buckets to catch the water as it drains or melts BEFORE you call for help to help protect your home from possible water damage.


There are two common reasons why:

  1. Check the batteries and power in your home – this could be a power source issue.
  2. If it’s not a power source issue, it’s likely that a safety switch has flipped due to a problem with your system causing it to shut off (and prevent you from turning it back on). This doesn’t mean the Thermostat is bad, its a warning signal that something is not operating correctly with your system and it’s shutting itself off to protect itself from damage. You will need to schedule a Service Technician to come out to perform a diagnostic and repair the issue. 

WHY DID MY DUCTLESS STOP COOLING? (especially if it’s a newer system)
If you have a high-efficiency ductless system or a high-efficiency Infinity inverter-driven heat pump system, high community usage during a heat wave or snowstorm can sometimes cause power surges that can interrupt the system’s communication.

If you have a system communication error, you can try and manually reset the system:
1. Turn the system off
2. Go to the breaker panel and flip the breaker off for 5 minutes
3. Then turn the breaker back on
4. Turn your system back on to see if restores cooling for you


Yes, we sell over-the-counter filters. Don’t know what filter you need? Call or text us at 541-747-7445 so we can look up your equipment and get your filter size(s) ready.


If you don’t have air conditioning, there are several rebates and incentives offered for high-efficiency heat pump/air conditioning systems for different types of homes. Contact us to find out what your home qualifies for.

Marshall's is here if you need us. You can contact us online by phone or text at 541-747-7445, or at our office during regular business hours.

It’s been an unbelievable year with covid, wildfires, and now…a heatwave. If a dinosaur ran through town, I don’t think we would blink an eye. However, we WILL get through this crazy time, by supporting each other, keeping a sense of humor, staying safe and working together. 

The Marshall’s Team

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