Furnace & heating
AC repair
Ductless mini splits
TraneSeasonal tune-up and full diagnostic on your Carrier, Trane, or Goodman system - readings shown to you before any repair is proposed
Diagnosis first, numbers second - you approve the repair price before a single part goes in.
Get your free estimateFast, Reliable Furnace Repair Across San Marino
Furnace repair in San Marino typically costs $150 – $700, with most jobs landing between $250 and $450 depending on the part. We run calls to San Marino seven days a week and can usually have a technician at your door the same day you call. If your furnace is down on a cold winter night, call (626) 657-5344 and you’ll talk to a live person, not a voicemail queue.
San Marino homes aren’t like the rest of Los Angeles County. Many were built between the 1920s and 1950s, with plaster walls, original or retrofitted ductwork, and floor plans that were never designed for central forced air. That matters when a furnace fails. A tech who doesn’t know these houses will swap a part and leave, and you’ll be calling someone else in three weeks. We know these homes. We know what fails in them and why.
Why Dalton Heating & Air Pasadena Is San Marino’s Preferred Furnace Repair Company
We’re a Furnace Repair team that has worked inside San Marino’s older estates, its post-war ranch homes, and the newer infill builds on St. Albans Road and around Lacy Park. Crews are dispatched from our Los Angeles office, but the technicians who show up in San Marino know the city’s streets, its design review rules, and the quirks of homes built before central air was standard. That local knowledge changes how we diagnose problems.
Every San Marino call runs under The Garrison Standard, the operating rules we’ve followed since 2003 as a Garrison Partners company. That means three things on every job, no exceptions: a written price before any work begins, a written guarantee on the repair that covers a full year, and a free return visit if that repair fails within the guarantee period. Marco Benitez, who leads our team, holds every technician to The Garrison Code: arrive inside the stated window, do the job by the book, leave the site clean, and stand behind the work for a full year. It’s not a menu of upgrades. It’s how every call works.
We answer the phone 24/7 with a live person. You’ll know who’s coming before they arrive because our technicians are background-checked and uniformed. And we service nine major residential brands, including Carrier, Trane, and Lennox, so the name on your unit rarely throws us.
Styles & brands we work with
Boiler Repair in San Marino
Boiler Repair in San Marino is a different trade than standard forced-air furnace work, and it shows up most often in the older homes that still run radiator heat. Homes built before the 1940s sometimes never got central ductwork. Instead, a boiler in the basement or a closet heats water that circulates through radiators in each room. When that boiler fails, you lose heat everywhere at once.
Most boiler repairs in San Marino run $150 – $700, with common fixes including circulator pump replacement, pressure valve repair, and thermostat or aquastat calibration. Older boilers that haven’t been flushed in years develop sediment that causes banging noises and uneven heat. A good repair starts with checking the expansion tank and pressure relief valve first, because those are the safety components that fail silently.
Circulator Pump and Valve Work
A dead circulator pump is the most common “no heat” call we run on San Marino radiator systems. The pump moves hot water from the boiler through the piping loop. When it fails, the boiler may fire fine but the radiators stay cold. We replace the pump, purge air from the lines, and check the zone valves to make sure each part of the house actually receives hot water.
Older Boiler Heat Exchanger Checks
If your San Marino home still has its original boiler from 40 or 50 years ago, the heat exchanger deserves a hard look before you spend money on smaller parts. A cracked exchanger leaks carbon monoxide into the living space, and we will not patch one and walk away. We’ll tell you honestly if the repair makes sense or if the money is better put toward a replacement.
Gas Furnace Repair in San Marino
Gas Furnace Repair in San Marino covers the standard forced-air systems that heat most of the city’s post-war and remodeled homes. These furnaces burn natural gas in a sealed combustion chamber and push heated air through ductwork. When they fail, it’s usually one of a handful of parts: the ignitor, the flame sensor, the gas valve, the blower motor, or the control board.
Repairs in San Marino typically run $150 – $700. An ignitor replacement is usually at the lower end. A gas valve or blower motor lands in the middle. A control board or heat exchanger replacement pushes toward the top of that range, and sometimes beyond if the system is old enough that parts are no longer manufactured.
Ignitor and Flame Sensor Failures
The ignitor is a small ceramic part that glows hot enough to light the gas. It’s the most common failure point on modern gas furnaces, and it usually gives no warning. One day the furnace fires; the next day it doesn’t. We stock common ignitors on our trucks, so we can often diagnose and replace one in a single visit to a San Marino home.
Gas Valve and Control Board Repairs
A failing gas valve may cause the furnace to light intermittently or not at all. A failing control board can cause codes that look identical. We test voltage and gas pressure before replacing either one, because guessing at a $400 part isn’t how we work. The written price you approve before we start is the price you pay, whether the fix takes one part or three.
Trusted Brands We Service in San Marino
We service Carrier, Trane, Lennox, Goodman, and five more major residential brands across San Marino. That matters because a tech who only knows one brand tends to push replacements over repairs when the unit isn’t in their comfort zone. Our technicians are factory-trained on nine brands, so we can diagnose accurately and repair what’s repairable. We also keep common parts stocked locally and can source San Marino-specific components fast when a part is uncommon.
See the difference
Before
After
Before
After
Before
AfterCommon Furnace Repair Problems We See in San Marino Homes
- Furnace short-cycling from hidden condensers. San Marino’s design review zones require condensers to be concealed behind landscaping or screens, which means the outdoor unit is often tucked into a side yard behind lattice or a hedge. When airflow gets compressed, the system short-cycles, and the furnace burns out parts faster than it should.
- Cracked heat exchangers in oversized units. Many San Marino homes have 30-year-old furnaces that were oversized when new. After insulation upgrades and window replacements tightened the envelope, those units now cycle too often, and the heat exchanger cracks from repeated thermal stress.
- High static pressure from original ducts. Homes built in the 1920s through 1950s often have ducts that were sized for gravity heat or added later as an afterthought. Drop a modern high-efficiency furnace onto undersized ducts and the blower motor works against resistance it wasn’t built for.
- Limit switch trips after remodel work. We see this on St. Albans Road, around Virginia Road, and in the estate lots near The Huntington. A homeowner adds insulation or replaces windows, the house gets tighter, and suddenly the furnace’s limit switch trips constantly. The fix usually involves airflow correction, not a new furnace.
Pricing for Furnace Repair in San Marino, CA
Most furnace repairs in San Marino land in the $150 – $700 range. Here’s what that looks like by service:
| Service | Typical Range in San Marino |
|---|---|
| Furnace Repair | $150 – $700 |
| Boiler Repair | $150 – $700 |
| Gas Furnace Repair | $150 – $700 |
The final price depends on the part and how accessible the unit is, and on some of San Marino’s older homes that means working in a tight crawlspace or a side yard the size of a hallway. We give every customer a written price before any work begins, every time. Call (626) 657-5344 for a free estimate, and that estimate is the number you’ll pay if you approve the work.
We Also Serve Cities Near San Marino
If you’re a neighbor just outside San Marino, we run calls throughout the area including San Gabriel, Alhambra, Pasadena, and Temple City. Response times are similar, and the same written pricing and one-year repair guarantee apply wherever you are in the area.
Serving San Marino, CA - Our Local Coverage Area
We’re based in the San Marino area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Furnace Repair in San Marino
Repair work generally doesn’t require design review, but furnace replacement in San Marino often does trigger review when the equipment location changes or new exterior penetrations are needed. Replacement with a like-for-like unit in the original location usually moves faster. We handle the paperwork and can tell you early in the process whether your street falls inside a design review zone and what the city will want to see.
A limit switch trip means the furnace is overheating, and in older San Marino homes the cause is usually airflow, not a bad switch. When you add insulation and seal windows, the house holds heat longer, the furnace runs shorter cycles, and the heat exchanger gets hotter because air isn’t moving across it fast enough. The fix is often a blower speed adjustment or duct modification to lower static pressure, not a limit switch swap. Call (626) 657-5344 and we’ll diagnose it properly.
In most cases yes, you can replace just the heat exchanger on a 1950s floor furnace, but the economics don’t always favor it. Heat exchanger replacement on a unit that age often runs near the top of the $150 – $700 repair range, and sometimes the part is discontinued. We’ll give you the honest math on repair versus replacement before you spend a dollar. The written estimate is free.
Short-cycling in San Marino usually comes down to clearance. The city requires condensers to be concealed, which means lattice, screens, and hedges press right up against the unit. We check clearance against the manufacturer’s minimum, trim back or reposition what we can, and in some cases add air deflection so the hot exhaust doesn’t recirculate back into the intake. A condenser that can breathe lasts years longer.
Yes, but the approach may be different from what a typical installer would propose. San Marino homes from the 1920s often lack conventional attic or basement space for ductwork, so a standard forced-air retrofit can be invasive and expensive. We’ve installed high-velocity mini-duct systems and multi-zone mini-splits in these homes, and in some cases a like-for-like replacement of the existing floor furnace or wall heater paired with a ductless system for cooling is the cleaner answer. Call (626) 657-5344 and we’ll walk the house with you before recommending anything.
We serviced a 1940s Spanish Colonial Revival on Winston Avenue where the furnace’s limit switch kept tripping. The original gravity ducts had been partially abandoned over the years, and static pressure was spiking every time the blower kicked on. Our tech replaced the blower motor and rebalanced airflow through the remaining ducts, then recalibrated the thermostat so the single-zone system stopped overheating the upstairs bedrooms. That’s the difference between guessing and diagnosing.
Furnace problems in San Marino don’t wait for business hours, and neither do we. Call (626) 657-5344 any time, day or night, and you’ll reach a live person who can dispatch a technician to your San Marino home. Written pricing, a one-year written guarantee on every repair, and a free return visit if the fix doesn’t hold. That’s The Garrison Standard, and it’s how we work on every job.
Written by Marco Benitez, Owner at Dalton Heating & Air Pasadena, serving San Marino with furnace repair, boiler repair, and gas furnace service since 2003.