Furnace Not Heating in Orinda

Furnace Not Heating in Orinda

Orinda is hillside custom-home country, mostly 1950s through 70s builds on grade-separated lots, and the furnaces here tend to live in awkward places. We find them buried in tight crawl spaces, wedged into hillside closets, fed by long original duct runs threaded through framing that was never meant to come apart. The location does not change why a furnace stops heating, but it absolutely changes how we get at it safely, so the first thing we do on an Orinda call is look at the install before we scope the repair.

Behind the access, the failures are the same handful we see everywhere. A no-heat furnace is nearly always one bad part, not a dead system. Orinda sits tucked behind the hills, so its summers run warmer than the bayside towns and its winters stay cool and damp, which means the furnace here is a true seasonal workhorse. It works hard for a few cold months and sits the rest of the year, and that on-off pattern is what wears these parts out.

On the older hillside homes we pay close attention to combustion safety and to those long restrictive duct runs, because that combination is exactly where overheating and carbon monoxide problems hide. We run a CO test and camera the heat exchanger on every gas furnace before we hand it back to you, and on a 50- or 60-year-old house that is not a box we check, it is the point of the visit.

Common causes

Hot surface ignitor that quit glowing. The ceramic element opens up internally and stops heating, so the burners get gas but nothing to light them. It is the most common reason a newer furnace goes cold. We meter it for continuity, eyeball it for the hairline cracks these develop, and swap it, $200 to $350 on most units.

Carbon on the flame sensor. The burners light fine, then the gas cuts a few seconds later and the cycle repeats, because a sooted sensor rod is not feeding enough signal back to the board to confirm flame. A scrub of the rod brings most of them right back. A rod pitted past cleaning gets replaced for $150 to $200.

Tired draft inducer or its pressure switch. The inducer is one of the first things to wear out on Orinda's older hillside furnaces, and a long flue run up a hillside chimney does it no favors. If it cannot pull a proven draft the pressure switch leaves the gas valve shut and you get no ignition at all. We read motor amperage and test the switch. An inducer is $400 to $700, the kind of number that opens an age conversation on an old unit.

Limit lockout from those long, tight duct runs. The original ductwork in these hillside homes is often long and narrow, and a dirty filter on top of that is enough to starve airflow and cook the heat exchanger until the limit shuts the burners off. We hunt down the real restriction, in the filter or the duct, and prove airflow is back. A reset alone just trips again next cold night.

Cracked heat exchanger on the older equipment. Past 18 to 20 years the exchanger metal fatigues and can split, which is a CO problem first and a heat problem second. We scope it on camera and put the crack on your screen before any quote. A confirmed crack means the unit comes out, and we red-tag and shut it off before we leave the property.

How we diagnose it

• Scope the install first, because crawl-space and hillside-closet access decides how we safely reach and pull the unit.
• Drive a full start cycle and pin down the exact step where the furnace gives up.
• Meter ignitor continuity and read the flame sensor in microamps against the unit spec.
• Walk the filter and the long duct runs for restriction, then camera the heat exchanger given how these hillside homes are ducted.
• Run a combustion CO test on every gas furnace before we clear it.

$75 diagnostic, credited toward any repair over $200. You get a written quote before any work begins.

Furnace Not Heating in Orinda: common questions

Nearby and related

Furnace Not Heating near Orinda: Lafayette · Moraga .

This is usually a furnace repair in Orinda job. See our furnace repair overview or the Orinda service area.