B.F.MAHN & SONS INC.


Call Us Today For Expert Comfort Services

636-586-2300

Welcome to B. F. Mahn & Sons, Inc!

For 6 generations, B. F. Mahn has delivered top quality work to meet your residential or commercial plumbing and HVAC needs. We serve clients across Jefferson County and beyond with a variety of services ranging from new construction plumbing to minor daily repairs.

Our business is built on a strong foundation and is known for its impeccable reputation and first quality service skills. From our beginning, we have worked to be the company you can trust, and have been resilient through ups and downs in the economy.


Heating System Services

Our team of heating repair contractors is always available to make sure your heating or hot water systems are running at peak efficiency. We service and repair all types, makes, and models of hearing systems including: gas, propane, geothermal, and electric. No matter if you're looking for routine maintenance or are in a heating emergency, we have the skills and expertise to make sure your system is in working order.

  • Furnace Service & Repair
  • Furnace Installation & Replacement
  • Boiler & Radiant Service & Repair
  • Boiler & Radiant Installation & Replacement
  • Geothermal System Service & Repair
  • Geothermal System Installation & Replacement
  • Heat Pump Service & Repair
  • Heat Pump Installation & Replacement
  • Ductless Split System Service & Repair
  • Ductless Split System Installation & Replacement

Air Conditioning System Services

Whether you need your air conditioning system serviced, repaired, or tuned up, we have the skills and expertise to handle the job. Our team of trained contractors can service any make or model of air conditioner and will expertly diagnose and repair the issue. We can also help you prolong the life of your unit through preventative maintenance services. Additionally, if you're looking to reduce your energy bills, we can help you choose the right energy efficient air conditioning unit for your home or business.

  • Air Conditioner Service & Repair
  • Air Conditioner Installation & Replacement
  • Geothermal System Service & Repair
  • Geothermal System Installation & Replacement
  • Heat Pump Service & Repair
  • Heat Pump Installation & Replacement
  • Ductless Split System Service & Repair
  • Ductless Split System Installation & Replacement

Water Heater Services

While a water heater is a must-have appliance in your home, service or replacement doesn't really come to mind until it is too late. There is no need to panic if your water heater stops working. Our team of technicians will guide you through the process of repairing or purchasing a new water heater. We will work to diagnose the problem, and if your unit needs replacement, we will work with you to find the model to fit your needs.

  • Tank Water Heater Service & Repair
  • Tank Water Heater Installation & Replacement
  • Tankless Water Heater Service & Repair
  • Tankless Water Heater Installation & Replacement
  • Heat Pump Water Heater Service & Repair
  • Heat Pump Water Heater Installation & Replacement

Plumbing Services

B. F. Mahn & Sons have always been in the forefront of plumbing services. We have provided communities in Jefferson County with plumbing repair, maintenance, and replacement services for 4 generations, and guarantee you will receive the best possible service at a competitive price.

In a lot of ways, the bathroom is one of the most important rooms in your home. If you're planning a bathroom remodel, it can be difficult sorting out the logistics, plumbing layout, and fixture placement. Whether you want to add another bathroom to your home or need to replace your bathtub, we are experts in the field. Remodeling your home can boost the value of your home, and we will help you make the most of your space without breaking the bank.

We have experience with all types of plumbing issues and repairs including:

  • Full General Plumbing Services
  • Fixture Repair, Installation & Replacement
  • New Construction Plumbing Design & Build
  • Plumbing System Service & Repair
  • Bathroom & Kitchen Renovation & Remodeling
  • Blocked drains
  • Blocked sewer lines
  • Blocked shower drains
  • Burst/ leaky pipes
  • Gas leaks
  • Leaking hot-water unit
  • Other plumbing issues
  • Sewer backups
  • Tap doesn’t turn off
  • Water pressure problems


About B.F. Mahn

B. F. Mahn & Sons have been family-owned and operated since 1868, and provides top quality plumbing and HVAC services to clients across Jefferson County, MO. For 6 generations, our family has taken care of families just like yours.

Services We Offer

For the best, commercial or residential plumbing and HVAC services look no further than B. F. Mahn & Sons. We provide a full range of trustworthy services for both individuals and business owners.

Products We Offer

We offer a range of plumbing and HVAC equipment brands, so you can find exactly what you're looking for. We are dedicated to helping you find the products and brands you want to enhance your home or business.