Welcome to the finest air conditioning, heating, plumbing and indoor air quality products and services for both residential and commercial California Bay Area customers.

Harry Clark started a service company called Grand Ave. Plumbing in 1946 and later moved to Piedmont Ave. Harry Clark along with his wife Madeline, ran a successful company. Some years later Mr. Clark passed away. Madeline Clark, came from a family of plumbers and had worked with her father when growing up. Madeline was not ready to retire, or sell. She applied and succeeded in becoming a California licensed plumbing contractor. She was one of the first in this state.

In 1976 Mrs. Clark was ready to retire. She found Donald and Beverly Marshall, who worked in the industry since 1952. They bought the company. They continued the tradition of the local company specializing in service. They hired their youngest son Brad Marshall, a union trained journeymen in 1985. By 1989 Donald and Beverly were ready to retire. They sold the company to their two son's, Brad and Don Marshall.

Today, Harry Clark retains its roots as a specialized service company. They have expanded the service base to include: sewer repair and replacement, heating and air conditioning service and installation. Today's company enjoys the status of a premier service contractor serving the Bay Area's needs.

Walnut Creek Air Conditioning
When the California summer sun cuts through the cool breeze off the Pacific, you want an efficient and reliable system keeping your indoor air cool. We provide air conditioners and heat pumps that use R-410A refrigerant and have high SEER ratings to save on our environment and your utility bills. Learn more about air conditioners and other products we offer!

Tankless Water Heater
Tankless water heaters are part of our environmental focus. A Tankless Hot Water Heater or On Demand Water Heater instantly heats water as you need it as opposed to using energy around the clock like typical hot water heaters do. Tankless systems reduce your energy consumption and utility bills while also providing you with an unending source of hot water! We offer Takagi® tankless systems for their superior efficiency ratings. Learn more: Tankless Systems.

Walnut Creek Heating
The Bay Area weather is nice, but our winters are still cold. Harry Clark is here to ensure your family is kept warm and comfortable during the winter season. Harry Clark technicians can service and repair any brand of furnace (or heat pump), and if you are looking for a new system we offer efficient products with high efficiency ratings (AFUE) that can substantially lower your utility bills!

Indoor Air Quality
Did you know that the EPA has shown indoor air can be several more times polluted than the air outdoors? Today modern homes are great at sealing out the elements with tight, efficient seals. However this in turn recycles pollutants, toxins, bacteria and mold into the air you breath. Harry Clark provides a suite of indoor air quality products that integrate into your HVAC system and work together to purify your indoor air. Learn more: Indoor Air Quality Products

Trenchless Sewer
Harry Clark specializes in trenchless sewer installations to save your landscape the destruction of typical sewer line trenching. Trenchless sewer replacement is not only the newest method to replace your sewer but is the best! Find out more: Trenchless Sewer.

Walnut Creek Plumbing
Harry Clark is here to take the pain out of your needs. We provide prompt and courteous residential / commercial service. Our technicians are experienced and ready to handle any situation that arises, and we recommend/use quality products like domestic made pipe and fittings. From repair to new construction, bath to kitchen, we are ready to satisfy all your requirements! Learn more about Harry Clark services: Walnut Creek Plumbing Contractor

If you have any questions, please do not hesitate to call us at . If you would like to schedule service online, just visit our service request form. Thank you for your interest in Harry Clark of Oakland, CA!