Furnace Not Heating in Oakland
Oakland's residential core runs heavy to early-century Craftsman bungalows, and the heating in those homes is all over the map: original wall and floor furnaces, gravity systems converted to forced air decades ago, and newer furnaces retrofitted into homes that never had ductwork. When the heat quits, the right diagnosis depends a lot on which of those you have, which is why we look at the actual equipment instead of assuming.
On the older equipment, no-heat usually traces to ignition or safety controls. Standing-pilot wall furnaces fail at the thermocouple or pilot assembly. Newer forced-air units fail at the hot surface ignitor or the flame sensor. Either way it is a part, not a dead house. Oakland's mild winters, lows rarely below 40, mean the furnace is not running flat out, so when it stops it is usually a component giving up rather than the system being overworked to death.
Safety carries extra weight on Oakland's old heating equipment. Aging wall and floor furnaces and original heat exchangers are exactly where we find carbon monoxide problems. We test CO and inspect the exchanger on every gas furnace call, and on the older stock that inspection is not a formality.
Common causes
Thermocouple or pilot failure on standing-pilot units. Many original Oakland wall and floor furnaces still run a standing pilot. A weak thermocouple lets the gas valve close even when the pilot is lit, so the burner never stays on. We test millivolt output and replace the thermocouple or clean the pilot orifice, an inexpensive fix on equipment otherwise worth keeping.
Cracked hot surface ignitor. On the forced-air units retrofitted into bungalows, a failed ignitor is the usual no-heat cause. The element does not glow, the burners do not light. We confirm with a continuity test and replace it for $200 to $350.
Dirty flame sensor. Furnace lights then quits a few seconds later on a loop because the board cannot prove flame. Carbon on the sensor rod is the cause. Cleaning usually solves it, replacement $150 to $200 if it is pitted.
Cracked heat exchanger on old equipment. On furnaces and wall units past 18 to 20 years, the exchanger can crack. That is a safety shutoff and a CO risk, not merely a heat problem. We inspect it on camera and show you the crack before we quote anything. A confirmed crack usually means replacement, and we shut the unit down before we leave.
Limit trip from restricted airflow. Old narrow ductwork and clogged filters starve airflow, overheat the exchanger, and trip the limit. We find the restriction and confirm airflow instead of just resetting the switch.
How we diagnose it
- Identify the actual heating type first, standing pilot, retrofit forced air, or gravity conversion, since the diagnosis differs.
- On pilot units, test thermocouple millivolts and the gas valve; on forced air, test ignitor and flame sensor.
- Inspect the heat exchanger on camera, especially on equipment past 18 years.
- Run a CO test on every gas furnace, with extra attention on old wall and floor units.
- Check filter and airflow to rule out a limit-switch lockout.
$75 diagnostic, credited toward any repair over $200. You get a written quote before any work begins.
Furnace Not Heating in Oakland: common questions
Do you come into Oakland, or stick to the Tri-Valley side?
My house has an old wall or floor furnace. Is it safe to keep running?
The pilot is lit but the furnace still will not heat. What gives?
Nearby and related
Furnace Not Heating near Oakland: Berkeley · San Leandro .
This is usually a furnace repair in Oakland job. See our furnace repair overview or the Oakland service area.
Furnace Not Heating in Oakland
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