Lennox sits at the premium end of the heating and cooling market — high-efficiency furnaces, AC, and heat pumps sold through a dealer network rather than off a big-box shelf. That comes with a catch homeowners discover at repair time: Lennox builds a lot of proprietary parts. Its SureLight control boards and igniters, its variable-speed blowers, and its iComfort communicating components aren't the generic, cross-brand pieces you'll find on a builder-grade system. Fitting the right Lennox-specific part — and reading a SureLight or iComfort fault correctly — is exactly where a tech who works on the brand pays for itself. Triton repairs Lennox furnaces, AC, and heat pumps across the East Bay, Tri-Valley, and Peninsula, and we source the proprietary parts these systems need.
This page covers the Lennox equipment we service, the alert codes and problems we see most, and what a repair typically costs in the Bay Area.
Systems we repair
- Gas furnaces — SureLight-controlled models in single-stage, two-stage, and variable-speed versions, from the Merit series up to the Signature line.
- iComfort communicating systems — variable-speed equipment that talks to an iComfort thermostat over a data bus and reports faults right on the screen. These need a tech who understands the communication side, not just line-voltage parts.
- Central air conditioners — condensers and matched indoor coils, single-stage through variable-capacity.
- Heat pumps — for the growing number of Bay Area homes going all-electric.
Common Lennox problems we fix
- E200 rollout lockout. A hard lockout that means flame escaped the burner area — typically a blocked heat exchanger, plugged burners, or poor venting. This is a lockout for a reason: it needs a tech, not a reset.
- E250 limit / airflow trip. The furnace overheated and the primary limit opened, almost always from restricted airflow — a dirty filter, closed vents, or restricted ducts. The most DIY-friendly Lennox code; start with the filter.
- E227 low-pressure switch open. The pressure switch won't confirm draft, so the burners never light — a blocked intake or exhaust, a clogged condensate line, or a weak inducer.
- E270 flame-not-proven soft lockout. The burner lights and drops out because the board can't confirm steady flame after several tries — usually a dirty flame sensor or a weak igniter.
- Igniter & flame-sensor failures. A weak SureLight hot-surface igniter or a fouled flame sensor sits behind most of the ignition-side E-codes above.
- AC won't cool — capacitor or contactor. A failed run capacitor (the outdoor fan hums but won't spin) or a pitted contactor is the common summer no-cool on a Lennox condenser.
- Proprietary control boards, variable-speed/ECM blower faults, and refrigerant leaks round out the list.
Lennox error & fault codes
Lennox furnaces use 3-digit alert codes with an E prefix — shown on a 7-segment display on the SureLight control board behind the access panel, or on the thermostat on iComfort systems. Unlike the blink-count boards on some other brands, these are read as a number directly. A quick note: a bare E1 or E2 is not a Lennox furnace code — that's generic thermostat or mini-split text and doesn't map to the Lennox chart. A few of the common alerts:
- E200 — flame rollout switch open (hard lockout).
- E227 — low-pressure switch open (venting, inducer, or condensate).
- E250 — primary limit open (restricted airflow, usually a dirty filter).
- E270 — flame not proven after several tries (flame sensor or igniter).
For the full list, the DIY-safe checks, and the codes where sources disagree, see our Lennox code guide:
- Lennox Furnace Error Codes — what E200, E250, E227, E270 and the rest mean, and which are hard lockouts.
Code meanings can vary by control-board generation, so always confirm the number against the diagnostic label inside your furnace's access panel before buying a part.
What it costs in the Bay Area
Lennox repairs come down to the failed part, and proprietary components can sit toward the upper end of a range. On the furnace side, a flame sensor runs about $90–$250 and a hot-surface igniter $120–$350 — the common ignition and flame fixes behind an E270 — while a blower motor is roughly $400–$700 and a control board $200–$600; most furnace repairs land in the $129–$800 range. On the AC side, a capacitor is about $120–$350 and a contactor $120–$320 (the cheap, common fixes), a refrigerant leak repair and recharge runs $180–$650, and a compressor is the high end at $900–$1,600, with most AC repairs in the $129–$1,200 range. We charge a diagnostic fee that's credited toward the repair when you approve the work, and you always get a firm, flat price before anything is installed.
Book Lennox service
Triton services Lennox furnaces, AC, and heat pumps — plus every other major brand — across the East Bay, Tri-Valley, and Peninsula, including San Mateo, Pleasanton, Dublin, Redwood City, and San Ramon. Same-week and often same-day appointments, licensed techs, and upfront pricing.
Book online or call (888) 993-5699.
Related pages
- HVAC Repair in the SF Bay Area — our full heating & cooling hub
- Lennox Furnace Error Codes — the E-code guide
- Furnace Not Heating / No Heat — the symptom behind most alert codes
- AC Not Cooling / Blowing Warm Air — the summer no-cool
- HVAC & AC Repair in San Mateo — Peninsula service area
- HVAC & AC Repair in Pleasanton — Tri-Valley service area
Frequently asked questions
What does E200, E250, E227, or E270 mean on my Lennox furnace? They're SureLight alert codes. E200 is a flame-rollout hard lockout (a serious one that needs a tech), E250 a primary-limit trip from restricted airflow (often a dirty filter), E227 a low-pressure switch open from a venting or inducer problem, and E270 a soft lockout when flame isn't proven — usually a dirty flame sensor. Read the number off the 7-segment display or the iComfort thermostat and confirm it against your unit's label.
Why are Lennox parts more expensive or harder to find? Lennox is a premium, dealer-channel brand that uses a lot of proprietary parts — SureLight boards and igniters, variable-speed blowers, and iComfort components — rather than the generic, cross-brand pieces on a builder-grade system. That's the main reason a Lennox repair benefits from a tech who knows where to source the right part instead of a near-fit substitute.
Can you work on a Lennox iComfort communicating system? Yes. iComfort systems are variable-speed and communicate with the thermostat over a data bus, so they need more than basic line-voltage troubleshooting. We diagnose comm faults, control boards, and variable-speed components on iComfort equipment, reading the alert codes it reports on the thermostat.
Why does my Lennox furnace light and then shut off? That short-cycle-on-ignition pattern usually shows up as an E270: the burner lights but the board can't confirm steady flame, so it shuts the gas off and locks out after a few tries. The cause is most often a dirty flame sensor or a weak SureLight igniter, both of which a tech can clean or replace.
How much does Lennox furnace or AC repair cost in the Bay Area? It depends on the part. A flame sensor is about $90–$250 and an igniter $120–$350; a blower motor runs $400–$700 and a furnace control board $200–$600. On the AC side a capacitor is $120–$350, a refrigerant leak repair and recharge $180–$650, and a compressor $900–$1,600. The diagnostic fee is credited toward the repair when you approve the work.
Do you service Lennox in my city? We cover the East Bay, Tri-Valley, and Peninsula — including San Mateo, Pleasanton, Dublin, Redwood City, and San Ramon — with same-week and often same-day appointments. Call (888) 993-5699 to book.