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Boiler Install, Troubleshoot and Service in San Francisco, CA
Steady Heat From a System That Stops Surprising You
Most boiler complaints trace back to water, air, or controls rather than to the boiler itself, which is why replacing a component without diagnosing the whole loop tends to produce a repeat call about 3 weeks later. Circulator direction, air separation, water quality, and expansion capacity all shape how a system behaves over a season. Malcolm Plumbing & Mechanical installs, diagnoses, and services hydronic and steam boilers throughout San Francisco, CA and the surrounding Peninsula cities.
Our mechanical crew works on residential units and commercial plants alike, from apartment building heating to process loops in light industrial spaces. We commission everything we install, document the settings and readings, and leave the system properly tuned rather than merely running. Licensed and insured, free estimates, a one-year labor warranty, and 35+ years of local mechanical work stand behind every job. Describe the symptoms through our contact page and we will bring the right diagnostics with us.
Explore Our Boiler Installation and Repair Services
For more information about lorem ipsum or to schedule service, call us at 415-621-1985 or click the button to fill out the form!
New Boiler Installation and Replacement
Sizing comes from an actual heat-loss calculation rather than from whatever capacity the old unit happened to carry. Oversized boilers short cycle, waste fuel, and wear their controls prematurely, so getting the number right shapes everything that follows afterward.
Hydronic System Diagnostics
Uneven heat, noisy pipework, and pressure that will not hold usually point to air, flow direction, or a failing expansion vessel. Working through the loop methodically finds the cause instead of replacing parts in sequence until something eventually improves.
Steam Boiler Service and Repair
Steam systems have their own vocabulary of faults: water line surging, failed air vents, waterlogged returns, and traps that have stopped closing. Correcting these restores even distribution and quiet operation, which is what steam does well when maintained properly.
Circulator, Zone Valve, and Control Repair
Pumps seize, zone valve motors burn out, aquastats drift, and control boards fail in ways that mimic other problems entirely. Isolating each component electrically before condemning it keeps the repair honest and the parts bill proportionate to the fault.
Combustion Testing and Efficiency Tuning
An analyzer reading tells you what the burner is actually doing rather than what the nameplate suggests. Adjusting the air and fuel mixture correctly improves efficiency, lowers stack temperature, and reduces the soot that fouls heat exchangers over a season.
Annual Boiler Maintenance
Yearly service covers combustion, safety controls, low-water cutoffs, relief devices, water quality, and the general condition of the piping. Most winter breakdowns we attend were visible as a small fault during the previous autumn if anyone had looked.
See Our Boiler Work
See how Malcolm Plumbing & Mechanical handles boiler installation, troubleshooting, and service for reliable heating across San Francisco, CA.
FAQ's
How often should a boiler be serviced?
Once a year, ideally before the heating season starts rather than during it. Commercial plants and steam systems warrant more frequent attention, which 35+ years of San Francisco, CA boiler rooms has taught Malcolm Plumbing & Mechanical repeatedly.
Why does my boiler keep losing pressure?
Something is letting water out or the expansion vessel has failed. Check visible piping and the relief discharge first, then the vessel charge. Persistent loss with no visible leak often means a buried pipe or a failed heat exchanger.
What causes a boiler to short cycle?
Oversizing is the usual answer, followed by restricted flow, a fouled sensor, or control settings that are too tightly spaced. Short cycling wastes fuel and wears components quickly, so it is worth diagnosing properly rather than simply tolerating it.
How long does a residential boiler last?
Cast-iron units regularly reach 25 or 30 years with maintenance, while modern condensing boilers typically run 12 to 15. Water quality, correct sizing, and whether the system was ever properly commissioned account for most of that variation between them.
Why are some radiators cold while others are hot?
Air trapped in the loop, an unbalanced system, a failed zone valve, or sludge collecting in the lower emitters. Bleeding and balancing resolves many cases, and where it does not, the flow problem is usually mechanical and locatable.
What does it mean when a boiler locks out?
A safety control has detected a condition outside its limits and shut the appliance down deliberately. Resetting without finding the cause simply postpones it. Repeated lockouts always mean something needs investigating rather than another press of the button.
Should I replace a boiler or repair it?
Age, efficiency, part availability, and the cost of the current fault together answer that question for you. A 30-year-old unit needing a heat exchanger is finished. Malcolm Plumbing & Mechanical gives straight assessments to building owners across San Francisco, CA.
Do steam boilers need different maintenance than hot water boilers?
Considerably. Steam systems need water line and cutoff attention, air vent checks, and return monitoring that hot water loops simply do not require. Treating a steam boiler like a hydronic one is a reliable way to shorten its life.
Why Choose Us for Boiler Install, Troubleshoot and Service
Diagnosis Before Parts
Swapping components until the symptom disappears is expensive and unreliable, and it is remarkably common in this trade. Working out what is actually wrong first means you pay for the part that fixes it rather than several that did not.
Systems Commissioned, Not Just Started
Firing a new boiler is not the same as commissioning one. Flow rates, temperature differentials, combustion figures, and control settings all get verified and recorded, so the system starts its life properly balanced rather than approximately close to it.
Heat Restored Quickly in Cold Weather
A building without heat in January is not a routine service call, and it does not get treated as one. Priority scheduling, stocked common parts, and after-hours availability keep an outage measured in hours rather than in days.
Documentation of Settings and Readings
You receive the numbers: pressures, temperatures, combustion figures, and control set points as we left them. That record makes the next service faster and gives any future technician a baseline instead of a system nobody can account for.
Coverage for Residential and Commercial Plants
The same crew handles a residential wall-hung unit and a commercial plant serving an entire building. That range means we understand how small systems and large ones fail differently, and we bring equipment suited to whichever one you have.
Compliance Work Handled Alongside Repairs
Larger installations also carry certification obligations that arrive on their own annual schedule. Coordinating repairs with those requirements means the equipment is ready when the inspection arrives rather than becoming a scramble at the least convenient possible moment.
Warmth That Holds Through a Cold Snap
Heating systems have a talent for revealing their weaknesses on the coldest night of the year, and almost always the warning signs were there weeks earlier for anyone paying attention. Malcolm Plumbing & Mechanical works the other way around, diagnosing the whole loop rather than the loudest symptom, commissioning what we install, and documenting readings so next winter starts from knowledge rather than guesswork. Buildings across San Francisco, CA rely on us for residential units and full commercial plants alike, in autumn service and in January emergencies. Get in touch through our contact page and tell us what your system is doing.
Why Choose Us
24/7 Emergency Plumbing
We provide 24-hour emergency plumbing services to help customers address urgent plumbing problems quickly. Our team is ready to respond when unexpected issues arise.
Comprehensive Plumbing Services
We handle a wide range of plumbing and mechanical needs, from sewer stoppages and hydro jetting to water heaters, boilers, fixtures, and general plumbing repairs. This allows us to provide convenient solutions for many different projects.
Experienced Sewer Solutions
We specialize in sewer camera inspections, pipe location, hydro jetting, stoppage removal, and sewer replacement. Our detailed approach helps us identify plumbing problems and determine the right solution.
Reliable Service & Repairs
We take pride in providing dependable workmanship and practical solutions for residential and commercial customers throughout San Francisco and surrounding areas. From water leaks and backflow systems to boilers and sewage ejectors, we are committed to getting the job done right.
Areas We Serve
San Francisco, CA
San Jose, CA
Oakland, CA
Fremont, CA
Hayward, CA
Sunnyvale, CA
Santa Clara, CA
Vallejo, CA
Concord, CA
Berkeley, CA
Richmond, CA
Antioch, CA
San Mateo, CA
Daly City, CA
San Leandro, CA
Redwood City, CA
Mountain View, CA
San Ramon, CA
Dublin, CA
Alameda, CA