Furnace & Heating Repair for Palo Alto’s cold mornings
Palo Alto winters are mild, but a 38°F morning in a house with no heat is no fun. We repair gas furnaces, heat pumps and wall furnaces, and we check combustion safety every time.
Call 650-460-3483438 Cambridge Ave, 94306
Furnace repair in Palo Alto covers gas furnaces, heat pumps in heating mode, and older wall and floor furnaces. Common causes of no heat are a dirty flame sensor, a failed igniter, a tripped limit switch from a clogged filter, or a blocked condensate line on high-efficiency units. ComfortFlow checks for carbon monoxide and cracked heat exchangers on every heating call.
Signs your heating needs attention
- The furnace starts, runs a minute, then shuts off
- Air from the vents is lukewarm or cold
- A burning, electrical or rotten-egg smell (for gas, leave the house and call PG&E or CPAU gas emergency first)
- New rattling, booming or squealing sounds
- The CO alarm has sounded, even once
- Heating bills jumped without a change in use
What we check on a heating repair
- Thermostat call, wiring and power to the unit
- Filter, blower motor and blower wheel
- Igniter, flame sensor and burner flame pattern
- Limit switches, pressure switch and inducer motor
- Heat exchanger condition and flue draft
- Carbon monoxide levels at the appliance and in the living space
- Condensate drain and trap on high-efficiency furnaces
Gas furnaces in Palo Alto homes
Many Palo Alto homes still have gas furnaces in attics, closets, crawlspaces or garages. The oldest are 20 to 30 years old, and some original wall and floor furnaces in pre-war homes are older still. We repair what makes sense to repair. When a heat exchanger is cracked or the repair is a large share of a new system’s cost, we’ll show you what a heat pump replacement would cost after the City of Palo Alto Utilities rebate.
Heat pumps in heating mode
A heat pump that isn’t heating could be stuck in defrost, low on refrigerant, or set up with thermostat settings that call for backup heat too often. Many “my heat pump doesn’t work” calls are fixed with configuration changes and a good airflow check.
Radiant and hydronic systems
Eichler radiant floors and hydronic baseboard systems use a boiler or water heater instead of a furnace. If yours is cold, see our radiant heating service page.
Common heating problems at a glance
| Symptom | Likely cause | What we do |
|---|---|---|
| Furnace starts, then shuts off | Dirty flame sensor, tripped limit switch | Clean sensor, check filter and airflow |
| No ignition | Failed igniter or control board | Test and replace failed part |
| Lukewarm air | Low gas pressure, dirty burners | Adjust and clean, verify temperature rise |
| Loud booming at startup | Delayed ignition | Clean burners, check gas pressure |
| CO alarm sounds | Venting issue or cracked heat exchanger | Shut down, inspect, repair or replace |
| Heat pump blows cool air | Defrost cycle, low charge, settings | Check refrigerant and thermostat setup |
Repair or replace a furnace?
If your furnace is under about 12 years old and needs a common part like an igniter, flame sensor or inducer motor, repair usually makes sense. If it is 15 or more years old, has a cracked heat exchanger, or needs a major repair, compare the cost against a heat pump. In Palo Alto, the CPAU Heat Pump HVAC rebate often makes replacement the better long-term value.
Why Palo Alto homeowners choose ComfortFlow HVAC Palo Alto for furnace and heating repair
ComfortFlow HVAC Palo Alto has served Palo Alto homes for over 10 years from our shop at 438 Cambridge Ave. Every heating visit includes a carbon monoxide check and a full safety control test, whether the system is a modern furnace, a heat pump or a decades-old wall heater.
- Diagnosis before recommendations. We measure first, then explain what we found in plain language.
- Repair prices up front. You see the cost before any work begins, and replacement only comes up when it makes sense.
- Local know-how. CPAU rebates, the City heat pump instant permit, Eichler radiant systems and Palo Alto’s older housing stock.
- Respect for your home. Drop cloths, protected floors and trim, and a clean work area at the end of every day.
Furnace & Heating Repair, step by step
- Safety firstCO and gas checks before anything else.
- DiagnoseIgnition, airflow and controls tested in sequence.
- OptionsRepair cost up front. Replacement context only if it helps.
- VerifyFull heating cycle and temperature rise confirmed.
Often paired with furnace & heating repair
Furnace & Heating Repair across Palo Alto and nearby
We’re based at 438 Cambridge Ave and work in every Palo Alto neighborhood. Local notes for each area:
New to us? Start with our overview of HVAC in Palo Alto.
Furnace & Heating Repair questions,
answered.
Answers from the ComfortFlow HVAC Palo Alto team about furnace & heating repair in Palo Alto homes.
Why does my furnace turn on and then shut off?
The most common cause is a dirty flame sensor that can’t prove the flame. A clogged filter tripping the high-limit switch is a close second. Both are quick fixes. Other causes include a blocked flue or condensate line on high-efficiency furnaces, a failing pressure switch, or a thermostat placed near a heat source. ComfortFlow HVAC Palo Alto tests each safety control in sequence so we fix the real cause instead of just resetting the furnace. We also check carbon monoxide levels on every heating visit.
Is it safe to run a furnace with a cracked heat exchanger?
No. A cracked heat exchanger can leak carbon monoxide into your air. We’ll shut the unit down and tag it if we find one, and walk you through repair or replacement options. Signs of a cracked heat exchanger include soot near the burners, a flame that dances when the blower starts, or a CO alarm. Make sure you have working carbon monoxide alarms on every floor. If the furnace is older, replacement with a heat pump is often more sensible than a heat exchanger repair, and CPAU rebates may help.
Should I repair or replace an old furnace?
If the furnace is over 15 years old and needs a major part like a heat exchanger or inducer, replacement with a heat pump is often the better value in Palo Alto because of the CPAU rebate. A simple rule: multiply the furnace’s age by the repair cost. If the result is higher than the cost of a new system, replacement deserves a serious look. ComfortFlow HVAC Palo Alto always quotes the repair first, then shows replacement options and the CPAU heat pump rebate so you can compare the real numbers.
Who provides gas in Palo Alto?
City of Palo Alto Utilities provides gas, electric and water service within the city. For gas emergencies, leave the home and call CPAU’s emergency line. Palo Alto is one of the few California cities that runs its own utilities, which is also why its heat pump rebates and electrification programs differ from PG&E territory next door. Nearby cities like Menlo Park and Mountain View get gas from PG&E. If you ever smell gas, leave the home first and call from outside.
Do you fix wall furnaces?
Yes, including older wall and floor furnaces common in pre-war Palo Alto homes. Many of these are good candidates for replacement with a ductless heat pump. Older wall and floor furnaces often lack modern safety features, and parts can be hard to find. We repair them when it is safe, always checking venting and carbon monoxide. Replacing a wall furnace with a ductless heat pump adds air conditioning, removes a combustion appliance and may qualify for the CPAU Heat Pump HVAC rebate.
Let’s make home
feel better.
Tell ComfortFlow HVAC Palo Alto what’s happening with your heating or cooling, and we’ll start with the right questions. Serving Palo Alto, Menlo Park, Mountain View, Los Altos, Stanford and the Peninsula.