Johnston Boiler Service and Repair in California
Service, code repairs, retubes, and ultra-low NOx retrofits on Johnston firetube boilers, from an independent company that builds boilers in California.
Code-built boilers and vessels
Code repairs and alterations

Factory-authorized Tech Center

Factory-authorized Burner Tech Center
Fifth generation, family-owned
QUICK ANSWER
McKenna Boiler Works, Inc. services and repairs Johnston boilers for plants across California. McKenna’s crews handle preventive maintenance, CSD-1 safety control testing, combustion tuning, retubes, refractory, and ultra-low NOx burner retrofits on Johnston boilers. Code repairs are done under McKenna’s National Board R certificate. McKenna is an independent company, not affiliated with Johnston, and builds its own boilers in an ASME code shop in Oceanside, California. Call (323) 987-1816 or email info@mckennaboiler.com to schedule service.
Johnston service
Service for the Johnston boiler you already have.
Johnston Boiler Company has built Scotch marine firetube boilers in Ferrysburg, Michigan, since 1864. Many still run process steam and central plant heat in California, and older units need tube, refractory, and burner work to stay safe and inside today’s air district limits.
McKenna services and repairs Johnston boilers with its own crews. We don’t sell Johnston equipment, so the recommendation is what the boiler needs: a repair, a retrofit, or a replacement when the numbers say so.
What we do
Johnston work McKenna performs.
- Preventive maintenance and CSD-1 safety control testing, with a written report
- Combustion analysis and burner tuning to hold efficiency and emissions
- Retubes, tube replacement, and new tubesheets drawn by McKenna engineers
- Rear door, front door, and burner throat refractory repair
- Ultra-low NOx burner retrofits selected to meet your air district’s NOx limit
- R stamp repairs and alterations under the National Board R certificate
Johnston scope
Models
All models of Johnston Scotch marine firetube boilers
Design
Scotch marine firetube, steam and hot water
Code work
National Board R certificate, repairs and alterations per the NBIC
Safety testing
ASME CSD-1 control and safety device testing where it applies
Emissions
Ultra-low NOx retrofits, as low as 2.5 ppm NOx (corrected to 3% O2) on select models
Controls
Autoflame, or controls from other manufacturers
Service area
All of California
Emergency
A live person answers (323) 987-1816 24/7
How it works
How a Johnston service call runs.
01
Send the nameplate
Call or use the request form. A photo of the nameplate tells us the model, size, and pressure before we arrive.
02
Inspection
A McKenna technician inspects the boiler, burner, controls, and safety devices, and notes what needs work now and what can wait.
03
Written scope
You get a written scope and quote. Code repairs list the R stamp work and the inspector hold points.
04
Repair and test
McKenna does the work, tests the safety controls, tunes the burner, and hands you the paperwork.
Why McKenna
Why plants use McKenna on their Johnston boilers.
Independent
McKenna isn’t tied to a manufacturer’s rep agreement. We recommend what fits your plant, including keeping the boiler you have.
We build boilers
McKenna engineers and builds boilers in its own ASME code shop. That’s the same knowledge we bring to your Johnston.
Code repairs in-house
McKenna holds the National Board R certificate, so welded tube repairs and other pressure part repairs don’t need another company.
One company for the boiler room
We service and repair other brands too. A plant with more than one brand of boiler gets one service company and one set of records.
McKenna Boiler Works, Inc. services and repairs all Johnston boiler models for plants across California. Its crews do preventive maintenance, CSD-1 safety testing, combustion tuning, retubes, refractory, and ultra-low NOx burner retrofits. McKenna is independent and not affiliated with Johnston.