Tell us about the job
Takes about a minute. No obligation.
Getting the sizing right on a boiler install here matters more than a contractor working a milder climate might let on. Homes in San Mateo County, CA run heat about seven months a year, from November through May. The burner and heat exchanger cycle through that load month after month, and a system that is undersized or installed with sloppy pipe work runs harder than it should across every one of those cycles. The heat exchanger takes the brunt. A contractor quoting a replacement has to work from the actual heat loss of the house, not from the capacity of whatever came out.
Ductwork laid down for an earlier generation of heating equipment was sized and routed for what that equipment needed, and a boiler going in now draws differently and distributes differently. Half the homes in San Mateo County, California were built in 1966 or earlier (2020-2024 ACS 5-year). A contractor quoting a boiler installation has to evaluate what is already in the walls before the new unit can be priced accurately, because the existing duct layout either fits the new system's requirements or it does not. That assessment changes what the job costs.
What Gets Installed With a New Boiler
The boiler itself sits in a utility room, basement, or mechanical closet and is the unit that heats water and sends it through the system. Alongside it, the expansion tank mounts nearby to absorb pressure changes as water heats and cools. The thermostat goes on an interior wall where the homeowner controls the whole system from one point.
From the boiler, supply and return pipes run through walls and floors to the radiators or radiant panels in each room, which is where the heat actually reaches the living space. The circulator pump attaches at the boiler and moves heated water through those pipes. A pressure relief valve and shutoff valves are fitted at the unit itself to give the contractor safe access and control.
The drawing shows a general layout of these components, and a licensed contractor determines exactly what applies to your home.
Get matched in San Mateo CountySan Mateo County, by the numbers
282 severe weather events were recorded in San Mateo County, California between 2015 and 2024.
NOAA National Centers for Environmental Information, Storm Events Database, bulk CSV export, events 2015-01-01 through 2024-12-31.Half the homes in San Mateo County, California were built in 1966 or earlier (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesSan Mateo County, California holds 287,184 housing units (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesOwners occupy 58.5% of the occupied homes in San Mateo County, California (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesBoiler Installation Rules & Codes for San Mateo County, California1 sourced standards and regulations
Licensing and Legal Requirements in San Mateo County, California
California requires a state contractor license: it is a misdemeanour to engage in the business of, or act in the capacity of, a contractor in California without one, unless the work is exempt.
Weather Events in San Mateo County That Put Heating Systems to Work
Boiler systems carry the load when outdoor conditions push a building's heating demand hard. How often that happens in San Mateo County shapes what equipment a contractor specifies, how it is sized, and how reliably it needs to perform.
282 severe weather events, 2015–2024. Source: NOAA National Centers for Environmental Information, Storm Events Database.