Boiler & Radiant Heat Service in Sausalito, CA
Local Plumbing has team members based in Sausalito, and hydronic heating is our specialty. We repair, service and replace boilers and radiant floor systems across town, from Old Town to Wolfback Ridge and down to the waterfront.
Pick a time online for a service visit or a written replacement estimate. No heat right now? Call or text.
Sausalito homes and the heating systems inside them
Sausalito houses don't sit on flat lots. They climb. A typical hillside home here has the boiler tucked into a lower-level mechanical room below the street, radiant zones on two or three floors above it, and a vent that exits a wall facing the bay. That layout, plus salt air and afternoon wind, is why heating systems in Sausalito wear differently from ones a few miles inland.
Old Town and Hurricane Gulch
This is where Sausalito started, and the streets still climb by stairs (the 2nd Street and Cable Roadway stairs among them). Getting a new boiler, an indirect tank, or even a full toolbox down to a lower-level mechanical room can mean carrying it by hand. The neighborhood gets its nickname from strong afternoon winds, and that matters for any boiler venting out a sidewall: wind-driven spray and gusts push exhaust back toward intakes and speed up corrosion on the termination.
Spring Street valley and up toward Cloud View Road
Much of this hillside was built in the 1950s. Homes here often have radiant systems that were added or extended over several remodels, so we see mixed tubing, mixed manifolds and zone valves from three different decades on one system. A careful map of what serves what comes before any repair.
Wolfback Ridge
The only part of Sausalito west of Highway 101: larger homes on exposed ridgeline lots, often with long runs between the boiler and the far zones. Exposure means higher heat loss on windy nights, so boiler sizing and outdoor-reset settings matter more here than in a sheltered house in town.
Marinship and the low waterfront
Parts of the Marinship already flood during storms and king tides; in January 2026 Gate 5 Road was flooded deep enough for a pedal boat. If your boiler, circulators or controls sit at grade near the water, we look at raising equipment or protecting electrical components when we replace it.
Floating homes
Some Sausalito floating homes do run hydronic radiant floors. Published examples include a three-story houseboat with radiant heat throughout the partly submerged hull and a hand-built passive-solar houseboat heated by radiant tubing under bamboo floors. Space on a floating home is tight, and every component is exposed to marine moisture, so equipment selection and access for service are the whole game. Note that Waldo Point Harbor is in unincorporated Marin County, so permits there go through the County, not the City of Sausalito.
Why multi-level radiant systems act up
A radiant system that spans three floors is a tall column of water. The higher it goes, the more fill pressure the boiler needs to keep the top zone full, and the more places air can collect. Most of the "top floor is cold" calls we get in hillside homes come down to one of these:
Fill pressure set for a one-story house
Water gains about 1 PSI of pressure for every 2.31 feet of height. A system with its highest loop 25–30 feet above the boiler needs more static pressure than a factory default fill setting provides.
Air trapped at high points
Without a working air separator and high-point vents, the upper manifold air-locks every time the system is drained or topped up.
Zones fighting each other
Old zone valves or a single undersized circulator trying to push water up three floors starves the far loops.
Mixing valve problems
Radiant floors need low-temperature water. A stuck or failed mixing valve either scalds the floor near the manifold or leaves it lukewarm.
Salt air, marine moisture and your boiler's venting
Bay air carries chlorides. On a modern condensing boiler, the parts that suffer first are the ones that touch outside air or acidic condensate: the vent termination, the combustion-air intake, exposed fittings and the condensate line.
At least one manufacturer's installation manual says that where sea-spray chlorides and high humidity are present, a boiler should be vented using indoor air for combustion rather than pulling outdoor air through a direct-vent intake, because indoor air carries less moisture and salt. Other manufacturers handle it through termination location and materials.
Either way, in Sausalito we check:
- Where the termination sits relative to the prevailing wind and the water.
- Whether the intake can re-ingest exhaust in a gust (common on tight Old Town side yards).
- The condition of the concentric kit, clamps and wall penetration.
- Corrosion on relief-valve piping, gas connections and circulator flanges.
- The condensate neutralizer. The acidic condensate drains to the sewer, and an exhausted neutralizer is easy to miss.
Symptoms we see, what usually causes them, and what we do
What Sausalito homeowners notice, and how we fix it.
Top floor or far bedroom never warms up
Usually: low fill pressure, air in upper loops, or an undersized or failing circulator.
We set pressure for the building height, purge each loop, and check the pump curve against the zone.
Gurgling or "running water" sound in upstairs floors
Usually: air in the system.
We purge, verify the air separator, and add high-point vents if they're missing.
Pressure drops below 12 PSI and the boiler locks out
Usually: a leak at a manifold, a relief valve weeping, or a failing expansion tank.
We pressure-test, check the expansion tank charge, and inspect every relief and fitting.
Pressure climbs toward 30 PSI when the boiler fires
Usually: a waterlogged expansion tank or a fill valve that won't close.
We recharge or replace the tank, and rebuild or replace the fill valve.
Boiler short-cycles on mild days
Usually: an oversized boiler, outdoor reset off or set wrong, or one small zone calling.
We adjust the reset curve and minimum run times, and review zoning.
Rust streaks under the vent or a white crust at the termination
Usually: salt exposure, or condensate leaking at vent joints.
We inspect the full vent run, replace corroded sections, and rethink the termination location.
Ignition lockouts or flame failures, especially on windy days
Usually: exhaust recirculating into the intake, a dirty flame rod, or a weak igniter.
We run a combustion analysis, clean or replace the flame sensor, and correct termination spacing.
Radiant floor warm at the manifold end, cold across the room
Usually: a failed mixing valve, a stuck actuator, or a restricted loop.
We test each loop, replace actuators or the mixing valve, and check for kinked or failed tubing.
Our radiant heating repair page and the post Radiant Heat Repair in Marin & Sonoma County go deeper on tubing leaks and manifold repairs.
Cold top floor in Sausalito? Get on our schedule.
Service it, repair it, or replace it?
Most Sausalito calls are repairs, and most repairs are worth doing. Replacing a boiler to cure an air problem or a bad zone valve is money spent on the wrong thing. Here is the straight version:
Repair or service makes sense when…
- The boiler is still well inside the typical 12–20 year life of a high-efficiency unit
- Parts are available
- The heat exchanger is clean and combustion numbers are good
Annual service with combustion analysis catches most problems before they become no-heat calls. See why annual boiler maintenance matters.
Replacement makes sense when…
- The heat exchanger is failing
- The manufacturer no longer supports the unit
- Venting is badly corroded and the boiler is already 15–25 years old
- Repair bills have become an annual event
Our published ranges vary job to job, and pump, manifold and valve upgrades add $1,200–$4,500. Access matters in Sausalito: a boiler that has to come down a public stairway takes longer than one in a garage. Details are on our boiler replacement page.
What about the gas phase-out?
The Bay Area Air Quality Management District's Rule 9-6 applies when equipment is sold or installed. Your existing boiler can keep running. For gas boilers in the size range most homes use (75,001 to 2 million BTU/hr), the zero-NOx standard applies to units manufactured after January 1, 2031 under the current rule. A July 2026 draft amendment would move that to 2033, and the Air District Board is expected to vote in November 2026. New gas boilers can still be installed today.
Permits and local rules in Sausalito
Who signs off depends on where your home sits. We handle it either way.
The City requires separate plumbing, mechanical and electrical permits as applicable, even for work that doesn't need a building permit. We pull the permit for a boiler replacement and schedule the inspection.
If your home is a designated historic resource or sits in a Historic Overlay District, changes to exterior appearance need a Certificate of Appropriateness. If a new boiler means a new vent through a street-facing wall, we check this first.
Floating homes at Waldo Point Harbor are in unincorporated Marin County, so County permits apply.
Marin Water (MMWD) serves Sausalito and lists boilers and radiant heat systems as cross-connection hazards that need backflow protection, with annual testing. See our backflow prevention page. The Sausalito-Marin City Sanitary District (SMCSD) requires a sewer lateral compliance certificate on sale, change of customer, change of use, or remodeling over $50,000. A boiler swap alone rarely triggers it, but a boiler replacement inside a larger remodel might. We don't do lateral work; we can refer you.
What a Local Plumbing boiler service visit includes
- Combustion analysis with a calibrated analyzer, and a look at the flame, igniter and flame sensor
- Vent and intake inspection outside and in, with extra attention to salt corrosion and termination spacing
- System pressure checked against the height of your house, expansion tank charge tested
- Air separator, high-point vents, and a purge of any zones that are air-bound
- Circulators, zone valves, actuators and mixing valve operation
- Condensate trap and neutralizer
- Outdoor-reset and control settings reviewed for your home's exposure
- A written summary: what's healthy, what to watch, and what to fix now
We service Navien, NTI, Lochinvar, HTP(including Munchkin), Laars, IBC, Viessmann, Noritz, Rinnai, legacy Triangle Tube and Weil-McLain/Burnham cast-iron boilers.
- Licensed C-16 & C-36 contractor(Lic #1091739).
- Rated 5.0 on Google across our San Rafael and Sausalito locations (340+ reviews).
- Owner Conor Crawford received the PHCC California Young Entrepreneur of the Year award in 2026.
What our customers say
Rated 5.0 on Google across our San Rafael and Sausalito locations (340+ reviews). A few from heating customers:
“The pump for my radiant heating went out in the middle of winter… Local Plumbing came right away… got the job done that day, on time, on budget and very professional.”Jeff S. · Local Plumbing customer
“Had to replace a failing gas/solar/radiant/domestic do everything 120 gal hot water tank. The job was complicated and a couple plumbers didn't even submit bids. You want Local Plumbing because they know all things radiant.”Naomi K. · Local Plumbing customer
“They helped us with a client that had issues with a defective radiant heat and hot water system. They were extremely kind and professional with our client who was raving about the work they did.”Alana C. · Local Plumbing customer
Sausalito boiler and radiant FAQ
Who repairs boilers in Sausalito?
Local Plumbing services and repairs boilers and radiant systems throughout Sausalito, Marin City and the floating-home communities, with team members based in Sausalito. Call or text (415) 234-0370.
Why is my upstairs radiant floor cold when downstairs is fine?
In a multi-level Sausalito home the usual causes are low system pressure for the building height, air trapped in the upper loops, or a circulator that can't push water that high. These are repairs, not a reason to replace the boiler.
How often should a boiler near the bay be serviced?
Once a year, before the heating season. Near the water we also look at venting and exposed fittings for salt corrosion at every visit.
Can a houseboat or floating home have radiant floor heat?
Yes. Some Sausalito floating homes run hydronic radiant floors. Space and marine moisture make equipment choice and service access critical. Floating homes at Waldo Point Harbor are permitted through Marin County.
Do I need a permit to replace a boiler in Sausalito?
Yes. The City of Sausalito requires plumbing and mechanical permits as applicable. We pull the permit and handle the inspection. Historic properties may also need a Certificate of Appropriateness for exterior vent changes.
Will I have to replace my gas boiler with a heat pump?
Not now. BAAQMD Rule 9-6 applies at sale or installation, and for most home boilers the zero-NOx standard covers units manufactured after January 1, 2031 under the current rule (a July 2026 draft amendment would push that to 2033). Your existing boiler can keep running.
What does boiler replacement cost in Sausalito?
Our published ranges run from $8,500–$15,000 for a high-efficiency boiler replacement up to $12,000–$18,000 for a radiant heating boiler system. Hillside access, venting and system condition move the number, so we give a written estimate first.
We work in Old Town and Hurricane Gulch, the Spring Street valley, Cloud View Road, Wolfback Ridge, the downtown flats, the Marinship and the floating-home docks, plus nearby Marin City, Mill Valley and Tiburon & Belvedere. For general plumbing, see our Sausalito page. For the full range of heating work, see Boilers & Radiant Heating and Boiler Repairs.
Cold top floor, a boiler that keeps locking out, or a vent that's rusting through?
Book a Sausalito boiler visit online, call or text us, or send us a message.
