At Plum HVAC, we're dedicated to bringing Foster City homes complete heating, cooling, and indoor air quality solutions that truly fit. Our licensed technicians aren't just experts in local climate challenges; they're also committed to a transparent, diagnosis-first approach. This means you get comfort, efficiency, and safety in every season, without the guesswork. We specialize in everything from furnace and AC installation to modern ductless mini-splits, custom ductwork design, smart thermostats, and comprehensive air quality systems. From detailed diagnostics and emergency repairs to proactive preventive maintenance, every service Plum HVAC provides is performed with precision and genuine care. We keep coastal conditions in mind, focusing on accurate system sizing, top-notch energy efficiency, and long-term reliability. Homeowners also appreciate our warranty assistance, guidance on rebates, and honest communication—it’s how we ensure dependable comfort and lasting value, all year long.

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(650) 605 – 5986

HVAC Company in Foster City, CA

Plum HVAC is a full-service HVAC company in Foster City, CA offering professional installation, repair, and maintenance for furnaces, air conditioning, heat pumps, and ductless mini-splits. We also handle ductwork, thermostats, zoning systems, and indoor air quality equipment. Foster City homes face unique coastal conditions and seasonal temperature swings that put specific demands on HVAC systems; this page explains the common issues we solve, how we diagnose and size systems, what to expect during service, and how our licensed technicians protect your comfort and indoor air quality.

Why local expertise matters for HVAC services in Foster City

Foster City’s mild, maritime climate and proximity to the bay mean less extreme cold but elevated humidity, salt air exposure, and occasional summer heat spikes. These factors affect equipment corrosion, refrigerant performance, duct moisture, and indoor air quality. An HVAC company in Foster City, CA needs experience with these local conditions to recommend the right systems and maintenance schedules that extend equipment life and keep homes comfortable year-round.

Our core HVAC services in Foster City

Furnace installation, repair, and preventive maintenance for homes that use gas or electric heating.
Air conditioning and heat pump installation, repair, and seasonal tune-ups to maintain cooling efficiency during summer heat events.
Ductless mini-split installation and service for room additions, retrofits, and targeted comfort zones.
Ductwork design, sealing, repair, and replacement to improve airflow and system efficiency.
Smart thermostats, zoning systems, and controls for precise temperature management and energy savings.
Indoor air quality solutions: high-efficiency filtration, UV germicidal lights, energy recovery ventilators (ERV/HRV), and whole-home air purification.
Diagnostics and emergency repair options to diagnose issues quickly and restore comfort.

Common HVAC issues in Foster City homes

Corrosion and premature wear on outdoor units due to salt-laden air from the bay.
Reduced cooling capacity during heat spikes caused by undersized or poorly maintained AC systems.
Humidity-related problems: condensation in ducts, mold growth, and inefficient dehumidification that affects comfort and air quality.
Thermostat and zoning problems leading to uneven temperatures between rooms.
Duct leaks and poor insulation that increase energy use and reduce comfort.
Refrigerant leaks or compressor failure in older systems that have not been maintained.

How we diagnose and plan HVAC work

We follow a structured, transparent process for every project so you understand system needs and expected outcomes:

Site assessment: Inspect the home, ductwork, insulation, attic and exterior unit location, and ventilation pathways. Evaluate exposure to salt air and other local conditions.
Load calculation and system sizing: Perform Manual J load calculations and, when needed, Manual D duct design to size equipment correctly for Foster City climate realities.
Options review: Present system choices—high-efficiency heat pumps, ductless mini-splits, upgraded filtration, zoning—and explain tradeoffs for comfort, efficiency, and cost of ownership.
Permitting and compliance: Prepare necessary permits and ensure installations meet local codes and manufacturer warranty requirements.
Scheduling and logistics: Coordinate arrival windows, site protection measures, and any preparatory tasks to minimize disruption.

Installation, repair, and maintenance explained

Installation: We follow manufacturer installation standards and best practices, including proper refrigerant charge, airflow verification, duct sealing, and electrical and combustion safety checks. For heat pumps and mini-splits, we verify line set routing, condensate management, and outdoor unit placement to minimize salt exposure and maximize airflow.
Repairs and diagnostics: Our technicians use modern diagnostic tools to pinpoint problems—electrical testing, refrigerant leak detection, airflow analysis, and control system diagnostics. We explain findings in plain language and outline repair options with estimated timelines.
Tune-ups and preventive maintenance: Seasonal tune-ups include filter replacement, coil cleaning, lubrication, thermostat calibration, safety checks, refrigerant level inspection, and airflow tests. Regular maintenance reduces energy bills, prevents mid-summer failures, and helps maintain warranty coverage.

Indoor air quality and ventilation considerations

Foster City homes often need balanced ventilation to control humidity and indoor pollutants without sacrificing energy efficiency. We evaluate the home for:

Filtration upgrades to MERV-rated filters or whole-house filtration when allergy or pollution concerns exist.
UV lights for microbial control on coils and in duct plenums.
ERV/HRV systems to bring in fresh air while recovering energy, particularly important in tightly sealed homes.
Dehumidification strategies for basements and crawlspaces to prevent mold.

Credentials, safety protocols, and warranty support

Plum HVAC technicians are licensed, insured, and hold certifications relevant to modern HVAC work, including EPA 608 certification for refrigerant handling and technician certifications such as NATE. We document work thoroughly and support manufacturer and workmanship warranties. For rebate and incentive support, we assist with documentation and specifications commonly required by state or utility energy programs.

COVID-19 safety measuresTechnician safety procedures include use of personal protective equipment, symptom screening, contact minimization practices, and enhanced vehicle and tool sanitation. We follow recommended protocols for indoor service, protect customer spaces during work, and offer options for contact-free paperwork and digital estimates.

Energy savings and local rebate assistance

The Bay Area and California often offer rebates and incentive programs for high-efficiency heat pumps, ductless systems, and qualifying controls. We provide guidance on energy-efficient system selection and help prepare the documentation needed for rebate applications. Proper sizing, duct sealing, and thermostat controls together deliver the best long-term savings and comfort for Foster City homes.

Preventive maintenance tips for Foster City homeowners

Replace or clean filters monthly during heavy use seasons.
Schedule annual cooling system tune-ups before warmer months and heating checks ahead of colder periods.
Keep outdoor units clear of debris and rinse salt buildup from exposed components periodically.
Seal attic and duct penetrations to minimize moisture movement and energy loss.
Monitor humidity levels and consider whole-house dehumidification if you notice condensation or musty odors.

Why Foster City residents choose Plum HVAC

With local climate knowledge, licensed technicians, and a focus on long-term performance and indoor air quality, Plum HVAC provides the full range of services Foster City homeowners need. From correct sizing and professional installations to thorough diagnostics, preventive maintenance, and warranty support, our approach is designed to protect your comfort, indoor air quality, and the longevity of your HVAC investment in this coastal community.

testimonials

hear what our satisfied clients have to say

5.0

We found Plum HVAC in 2024 after spending more than 2 months searching and comparing estimates. The owner Sam gave us a very competitive price for a Mitsubishi mini-split and the installation went off without a hitch. Our experience was so positive that we later requested their services twice more to also install A/Cs for our 2 other rooms. Their technician, Jake, led our installations each time and we were very impressed by their professionalism and quality of work. Now 1 year in and we could not be any happier, nor have we encountered any issues with our models.

Jesse Y.

5.0

Sam of Plum HVAC, responded to our Heat Pump installation request promptly and provided a very competitive estimate after an onsite visit. He was very flexible and patient to answer and explain our questions. After we signed the contract, he and his team of 4 worked very hard to deliver and install the whole Heat Pump system on time with good quality. I am particularly impressed by their problem solving skills to overcome different connection challenges for the attic installation. Each day before they started, they covered the floors with protection blankets and cleaned after they were done for the day. They also revised the drainage and electric work per the city inspection guidance. Sam and his team were professional and honest so we highly recommend Plum HVAC to any customers who need HVAC work done for their houses.

Chunshi C.

5.0

We needed to install a mini-split in a backyard unit. Sam and his team helped with this, and they did a fantastic job. Sam visited our place and clearly explained to me what needed to be done, and offered a great price. He scheduled the job for a few days later, and his team performed the job with extraordinary quality. Later, I noticed a minor issue and reached out to them. Sam helped me to fix the issue on a second visit by his team later in the week, providing top-notch customer service. I will work with them in the future for my HVAC jobs, and highly recommend them given their excellent work quality and customer service.

Majid J.

5.0

I reached out to 4 companies for mini split quotes; Plum HVAC pricing came in the lowest. Beyond that, Sam was very knowledgeable and kind during the in home consultation. He offered a quote in person, & stuck by it. They removed our old furnace, and installed a two head mini split in our two story townhouse. The work as you can see is very clean! The guys who installed it were very fun & professional. Sam & his team were communicative the whole way through including the permitting process. They took roughly one full day for install, which was very fast! Including removal & disposal of our old furnace. Natalie was very helpful throughout the Bayren Rebate process & always available for any questions! This system has changed our lives, wish we would have gotten it done sooner! It’s way better than we could have imagined.

Bobby R.

5.0

Plum HVAC exceeded my expectations in every way. Sam and his installer team were not only professional but also incredibly responsible throughout the entire process. They provided top-notch service at a very reasonable price, which is hard to come by these days. I highly recommend Plum HVAC to anyone looking for quality HVAC services. You won't be disappointed!

A Chui

5.0

I recently engaged Plum HVAC to install two mini-split units at my residence, and I'm thrilled with the outcome.Throughout the entire process, from the initial consultation to the project's completion, Plum HVAC showcased professionalism and expertise. The technician, Sam, arrived promptly and conducted a comprehensive assessment of my HVAC system. Sam took the time to thoroughly explain the technicians' tasks, the estimated duration of the project, and provided transparent pricing options.

Romero J.

5.0

Wonderful experience with Plum HVAC on a heat pump installation! I checked several companies, compared their recommendations, timelines, reputations and prices.Sam, the owner, was very professional and has almost 2 decades of experience in HVAC. When I asked dumb questions, he answered most graciously. And when I noted that some companies we queried said we could get away WITHOUT replacing our original ductwork from 1965, he gave us his honest opinion why that wasn't a good idea. (Hubby remembered later that people who worked in our attic adding insulation told us there were lots of duct leaks.)

Marlene S.

5.0

I called 8 different HVAC companies for quotes for a heat pump heating/ac system because I want to save money by switching from a forced air gas furnace to an electric heat pump system which will give me both heating and air conditioning. In addition my old furnace (circa 1991) was way oversized for my home and the air coming out too noisy. The New heat pump system is quieter and more efficient. Back to the quotes for the system, all the other 7 companies sent a salesperson/advisor to give the quote. Sam, the owner of Plum HVAC came our to give the quote. He was quick with his quote and was very knowledgeable. He didn't try to upsell me on anything and have the lowest quote of them all. His price was 60% less than the highest quote and 15% lower than the next second lowest quote.

Michael C.

5.0

Plum HVAC is an extremely professional, knowledgeable, and an established company to hire. I highly recommend Plum HVAC! Sam and his crew did a wonderful job. Sam worked with my schedule and his crew had completed the job with ease.

Blake

5.0

Sam was one of the most professional business owners I had the chance to meet over the past few years and I'm so happy I trusted him to install our new A/C unit.- He showed up on time- He was transparent (and reasonable) regarding pricing- He offered 2-3 options- His crew did a very clean/thorough jobWhat I loved the most though, was the fact he was very easy to communicate with. I would definitely use him again and recommend him to our neighbors/friends.

Bruno L.

5.0

We recently had a complicated Bryant Evolution dual fuel system with variable speed and zoning installed in our home by Plum HVAC, and we are very pleased! The team also changed the entire crawl space ducting, ensuring a comprehensive upgrade. The price was fair, and the team was always on time and easy to contact. Sam Mousavi, the head of the team, paid great attention to detail and demonstrated a strong understanding of systems. His expertise in HVAC systems and his friendly character made us feel comfortable throughout the process. We highly recommend Plum HVAC for their professionalism and excellent service.

Amirali B.

5.0

I cannot say enough about Plum HVAC, who replaced my aging heater furnace, and in particular Sam. Sam was very highly recommended by my sister, who replaced her furnace and added air conditioning.First, they gave me a good deal for a 2-stage, at the same cost as the lowest bid for a 1-stage. The other bids were dancing around some gas line work made by previous owners.

Kumar S.

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