Air Conditioning Maintenance

Air Conditioning Maintenance in San Diego County for a System That Works Better and Costs Less

Noticing warm air, weak airflow, or odd noises coming from your AC? At Guthrie & Sons, our 26-point air conditioning maintenance catches problems early and keeps your system in great shape. Whether it’s your home, rental, or business, we’ll get your AC clean, efficient, and ready for even the hottest weather.

Stay Cool, Save Money, and Keep Your AC Going Strong

It’s easy to skip air conditioning maintenance. When your system seems to be working fine, it’s not exactly top of mind. You’re busy, the house feels cool enough, and there’s always something more urgent to take care of. But here’s what we see all the time: clogged filters that choke off airflow, refrigerant leaks that go unnoticed, and dirty coils that force your system to work twice as hard just to keep up. That wear and tear builds up until suddenly your AC isn’t cooling, your energy bill jumps, or something breaks completely—usually on the hottest day of the year.

Every AC system needs maintenance, whether it’s brand new or has been hanging in there for 10+ years. That includes central air, heat pumps, and ductless mini splits. At Guthrie & Sons Heating, Air & Solar, we handle it all—residential and commercial, systems we installed and systems we didn’t. Don’t wait for something to go wrong—contact us for air conditioning maintenance in San Diego, CA, today and keep your cool all year long.

What is an AC Tune Up Anyway?

An AC tune up is a full check-up for your air conditioning system. Our HVAC technicians clean components, test key functions, check refrigerant levels, inspect electrical connections, and make sure everything’s running safely and efficiently.

Obvious benefits? You’ll stay more comfortable and save on energy bills and air conditioning repair services. Lesser-known ones? You’ll keep your warranty valid and extend the life of your AC unit. Whether your system’s brand new, older, or somewhere in between, an AC tune up with us is one of the best ways to protect your investment and avoid those sweaty, mid-summer surprises.

How Often is AC Maintenance Required?

In San Diego, we recommend scheduling air conditioning maintenance services at least once a year, ideally in the spring, before the summer heat hits. That gives us time to catch any air conditioner repair issues and get your system ready for heavy use. If you have a heat pump that also heats your home, it’s smart to schedule a second checkup in the fall.

Common Signs You Need Air Conditioning Maintenance

If your air conditioning unit isn’t keeping up like it used to, these are some of the most common signs it’s time for a tune up:

Warm air coming from your air vents instead of cool air
Weak airflow or inconsistent temperatures
Higher energy bills without explanation
Strange noises or musty smells
AC system is running longer than it used to

If you’re noticing any of these—or it’s just been a while since your last AC maintenance service (or you’ve never had one)—now’s the time. Call or schedule online today and let us help get your AC system back on track. Don’t forget to check out our special offers for extra savings!

INSTALLATION

Up to $1,500 Off a New System

Receive up to $750 in manufacturer rebates and up to $750 discount from Guthrie. Valid on select systems. Must mention promotion at time of estimate appointment. Not valid on prior sales. Cannot be combined with any other offers. Restrictions apply. See dealer for details. Offer expires 7/31/2026.

INSTALLATION

0% APR for 24 Months

Get 0% APR financing for 24 months on a new heating or air conditioning installation. 0% interest with 24 equal monthly payments.

Financing subject to credit approval. Valid on select systems only. Valid on residential properties only. Cannot combine with other offers. Must mention promo at time of estimate appointment. Restrictions apply. See dealer for details. Offer valid for an estimate appointment scheduled before 7/31/2026.

REPAIR

Free Diagnostic w/ a Repair

Your diagnostic service call fee will be waived if you proceed with a repair.

Cannot combine with other offers. Restrictions apply. See dealer for details. Offer expires 7/31/2026.

WATER HEATER

Free Estimate on a New Heat Pump Water Heater Installation

Valid for an estimate for a new hybrid heat pump water heater installation or replacement.

Restrictions apply. See dealer for details. Offer expires 7/31/2026.

Experience the Full Power of Our 26-Point AC Maintenance Checklist

But what sort of regular maintenance does an air conditioner really need? For some AC companies, it’s a quick glance, a bill, and they’re on their way. At Guthrie & Sons, we take it much further—because real air conditioning maintenance should actually improve your system.

We go deep with a 26-point checklist that covers every part of your AC, from airflow and wiring to refrigerant and performance. It’s not about doing the bare minimum—it’s about making sure your system runs better, lasts longer, and keeps you comfortable all season.

Clean Outdoor Unit: We remove debris, dirt, leaves, and more from the condenser coils.
Clean Outdoor Coils: We rinse the coil for better airflow and energy efficiency.
Inspect and Clean Air Cleaner: If your system has one, we clean all components.
Clean or Replace Standard Filter: We’ll clean washable filters or replace disposables. (You supply it, or we can.)
Inspect or Replace UV Bulbs: If you use UV purification, we’ll inspect or swap bulbs. (Bulbs can be supplied or purchased.)

Check and Test Drain Lines: We check for clogs that could lead to leaks or water damage.
Check and Test Condensate Pumps: We make sure pumps are operating safely.
Check and Test Condensate Switches: We verify that the safety switches are working to prevent overflow.

Visual Inspection of Indoor Coil: We check for dirt and corrosion.
Visual Inspection of Ductwork: We make sure it can maintain proper airflow.
Check Line Set Condition: We inspect refrigerant lines for wear, damage, or kinks.

Check Thermostat Operation: We make sure your thermostat is responding and reading accurately.
Inspect and Tighten Electrical Connections: Loose wires cause trouble—we make sure everything is secure.

Inspect Outdoor Fan Blades: We look for cracks or damage.
Test Amps of Outdoor Fan Motor and Compressor: We test for proper performance and early failure signs.

Check Refrigerant Charge and Type: We confirm refrigerant levels are accurate and match your system requirements.
Check Suction and Discharge Pressure: We verify that pressures are within safe, efficient operating ranges.
Check Superheat and Subcool Readings: We take advanced readings to fine-tune refrigerant performance.
Check Outdoor Ambient Temperature: We record outside temps to compare system performance under current conditions.
Check Return Air Wet-Bulb and Dry-Bulb Temperatures: We measure humidity and temperature of return air to assess cooling efficiency.
Check Supply Air Dry-Bulb Temperature: We confirm the cooled air leaving your vents is at the correct temperature.

If you did the math, that’s 26 detailed steps—because your system deserves that level of care. After your air conditioning maintenance, we’ll walk you through what we found. If everything looks good, we’ll show you how to keep it running strong for the season ahead. If we spot something that needs attention, like low refrigerant, a worn part, or signs your system is slowing down, we’ll explain your options clearly, whether that’s a simple AC repair or planning for a future air conditioning replacement. You’ll get a full report for your records (and warranty), and a clear path forward.

Keep Your AC in Top Shape With a Maintenance Plan That Pays Off

Staying on top of air conditioning maintenance shouldn’t feel like a chore, and with our USA Membership Plan, it doesn’t! We’ll remind you when it’s time for service, handle the scheduling, and show up ready to take care of everything from filter changes to system checks. Members enjoy real perks like priority scheduling, discounted service calls, 15% off all repairs, and an upgraded 5-year warranty.

Whether you have a central HVAC system or a ductless mini split, we have a plan that fits your heating and cooling setup and keeps your comfort on track. Call our office or talk to your technician about signing up!

Frequently Asked Questions

Yes, even if your system seems fine, skipping yearly HVAC service is one of the top reasons we get called for AC repair. Over time, wear and tear builds up, and catching small issues early can save you from bigger, costlier problems later. Annual maintenance also keeps your system working efficiently, especially in San Diego’s long cooling season.

We recommend filter replacement every 1–3 months, depending on your home and lifestyle.
Dirty air filters restrict airflow, raise your energy bills, and make your AC work harder. It’s a common reason for many air conditioner repair calls. Changing your filter regularly is one of the easiest ways to improve performance and avoid HVAC issues.

Yes—homes with pets often need more frequent AC service. Pet hair and dander clog filters faster, reduce airflow, and can lead to dirty air filters that affect system performance. We’ll help keep your HVAC system clean and efficient with the right service plan.

Pricing on our air conditioning services in San Diego depends on your system and setup, but we keep it fair and transparent. We offer one-time tune-ups or ongoing HVAC service through our USA Membership Plan, which includes perks like discounted repairs and priority service.

Real Reviews From Real Customers

We do things differently, and our customers appreciate it. See what some of our thousands of satisfied customers have to say about working with us.

Jim Hainline

3 weeks ago

We had Rob from Guthrie & Sons come out to repair one of our A/C units. Rob was very friendly and professional. Rob resolved the problem quickly.
As far as price goes, I paid a higher flat fee 12 years ago from one of the larger local companies. I'm very impressed with pricing and quality of work.

I highly recommend Guthrie & Sons and Rob.

Amy Graeber

3 weeks ago

Great experience! The company confirmed my appointment and let me know who my technician was via text. They also updated me when he was on his way. The technician was friendly and knowledgeable. I’d recommend Guthrie & Sons to friends and family.

Bobby Orozco

3 months ago

Great experience working with Guthrie & Sons from start to finish. Vlad was awesome. He was incredibly knowledgeable and explained everything in detail. Stark contrast from other companies we received bids for.

Christian and his crew did a great job on the install everything was smooth from start to finish.

I would definitely recommend this company here in Murrieta.

Sharon Troeger

3 months ago

Guthrie & Sons has always been super professional and knowledgeable about our system. They did the install a few years ago and have continued to maintain it for us. This year we noticed that our system wasn't performing as well, so when Wayne came out, he noticed a likely leak and was back 2 days later to find and fix it. He was quick, professional, and just extremely nice! 100% recommend.

Jeff Haight

4 months ago

Called one of the "big guys" in town and the estimate to do what needed to be done to diagnose my problem was nearly 1/2 the cost of the system when I purchased it and had it installed 5.5 years ago, I found Guthrie & Sons and they came out the same day and did the same work for 1/4 the price I was quoted for the same exact work! Daniel was friendly, honest and quickly got my system working as expected. I even purchased the service plan so I don't have future problems. I highly recommend these guys, they were awesome, don't get ripped off call Guthrie & Sons!!!

Rocky

4 months ago

I highly recommend Guthrie & Sons; from setting the appointment to the actual service!! Daniel was prompt, able to take care of our issue at a very reasonable price. I will be using them for all our needs in the future!!!! Thanks Daniel and Mackenzie.....you were great!!

Troy Nabatilan

5 months ago

Matt and Bryan are truly the A-Team! Their teamwork was outstanding and the workmanship was meticulous. The air handler was carefully installed, wiring neatly secured, plenum perfectly fitted, and the condenser precisely positioned and leveled for proper clearance and vibration control. The line set was pressure-tested and vacuumed as well. They also left the work area clean and neat.

Please congratulate them for a job well done!

Johnathan Yang

5 months ago

Guthrie and Sons was very professional and communicative. Matthew and Bryan did incredible work, and followed up with a lot of testing to make sure my new unit was functioning well. They went above and beyond to ensure that things were done correctly. I could tell their standards were extremely high, and I felt relieved seeing how much care they took in their installation. I’m very pleased with the result!

Sunyim Kim

5 months ago

I called to estimate to install central air conditioner on our second floor condo. Manager came the next day very punctual and knowledgeable about the process. He listened carefully our concerns and let us to make a decision. We truly appreciate his professionalism. Thank you for your service and I would recommend anyone who needs heating and air conditioning services in San Diego.

saul

5 months ago

Guithre and Sons distinguish themselves not only through their high level of professionalism but also by their unwavering commitment to the quality and durability of every product they sell and the meticulous craftsmanship involved in each project. The company operates with a strong dedication to integrity and respect, fostering long-term relationships with clients and suppliers alike. They prioritize transparency and ethical standards in all business dealings, ensuring customer satisfaction and trust at every interaction. Their customer service team is exceptionally responsive and knowledgeable, consistently exceeding expectations to resolve issues swiftly and effectively.

Ariana Lujan

6 months ago

Very helpful, quick and easy to schedule! We had an unexpected (but necessary) repair when doing maintenance and both the office and tech Carson were thorough and transparent in their support. Great service!

Graham Davis

6 months ago

After dealing with several HVAC companies, Guthrie & Sons clearly stood out as the most ethical, honest, and reliable. From the very beginning, their approach felt transparent and genuinely focused on what was best for us—not on upselling or unnecessary replacements.

We worked with Vlad T., who had previously been out to our home and saved us tens of thousands of dollars by getting our existing AC unit up and running when other companies were pushing for a full replacement. That experience alone earned our trust.

Now that we’re finally ready to purchase new units, there was no question that Guthrie & Sons was the only company we would consider, and Vlad was the obvious choice. He was extremely professional, punctual, and exceptionally knowledgeable, taking the time to explain options clearly and thoroughly. His expertise and honesty made the entire process straightforward and stress-free.

If you’re looking for an HVAC company you can truly trust—one that values integrity, quality workmanship, and customer service—I cannot recommend Guthrie & Sons and Vlad T. highly enough. This is how service should be done.

Blas Falconer

6 months ago

The layout of my condo made installing splits challenging, and before I met with Guthrie and Sons, three companies either told me that it couldn't be done. Vlad studied my apartment until he found a way to install with minimal openings in the walls and without a second condenser. Mallory, who works in the office, always followed through and advised me when I ran into a hiccup and needed detailed plans for the city. My HOA appreciated Guthrie and Sons' thoroughness and was so impressed with the design, that another resident who had been wanting splits for years, decided to install splits at the same time. The team that came in was knowledgeable, professional, and hard working. They finished a day ahead of time. I'm thrilled with the way everything looks and works.

Rob

6 months ago

This is by far the best company for your HVAC needs. They are honest very caring. Good fair pricing and got the job done efficiently and on time. I also signed up for their bi-yearly service which they performed the winter one and went very well. Thanks

Tania Reyes

7 months ago

I’ve been using Guthrie & Sons for over 15 years. They installed my whole AC system and maintained it all those years and never had an issue. Well it was time for an upgrade and they’ve recently installed my second system. The team 15 years ago and the team this time around were both amazing, professional and clean. I can’t recommend them enough Matt, Ben, Christian and Bryan get 10 stars. They are a bit pricier but worth the investment when you have peace of mind and almost two decades of great service and no issues.

Trejos Marcela

7 months ago

I had an excellent experience with Guthrie & Son AC & Heater Company. Their customer service was outstanding, and they took the time to answer all my questions thoroughly. Every technician who has worked on my AC/heater installation and now the ongoing service has been knowledgeable, respectful, and always on time. I highly recommend them to anyone in need of HVAC services!
I only wish the annual service was cheaper 🙂

Paula Remmel

7 months ago

I have a maintenance plan for my heat pump and air conditioner which Guthrie & Sons installed two years ago. I am very happy with my system as well as the maintenance plan. Wayne, one of their excellent technicians, just completed the Fall service and now the system is ready for winter use. He is knowledgeable and has been able to answer any questions I have about my system. In addition, the office at Guthrie & Sons is very responsive and follows through on any questions and concerns within 24 hours if not immediately. Great service from a great company.

Bill Cogan

8 months ago

Guthrie & Sons responded immediately to my online request, and was able to send someone out immediately. Zack, our technic-ian was very friendly, professional, knowledgeable and gladly answered all of our questions. He found the problem immediately, and left the work area clean and in good order. We would highly recommend Guthrie & Zack! They are real assets to our community.

Dani P

8 months ago

I've been using Guthrie & Sons for over 10 years and two homes. I really like that they are a family-owned and an established business. Always professional, on time, and always quality work. I've used their services from simple routine maintenance to having a new AC installed.I've never had a bad or even mediocre experience; I'm just always overall pleased with their work.

David Downhour

8 months ago

We bought our HVAC system from Guthrie & Sons. They have been monitoring our system online and later noticed a heat sensor issue.

Zach M. came by and installed on new one. He was extremely professional and completed the installation promptly.

This was another great experience all around and I gladly recommend Guthrie and Son's for all your HVAC needs.

Schedule Your San Diego Air Conditioning Maintenance With Guthrie & Sons

Every summer, we get called in for emergency AC repairs that could’ve been prevented with a little routine maintenance. If you want to avoid major problems and costly repairs, we’re here to help. Guthrie & Sons Heating, Air & Solar provides expert air conditioning maintenance in San Diego, California, plus reliable service to surrounding cities. From tune-ups to full AC service plans, our HVAC company offers what your cooling system needs to last. Schedule service today!

8248 Ronson Road
San Diego, CA 92111

(619) 269-3013

Air Conditioning Maintenance