Furnace
The Blinking Light on Your Furnace Is Talking: How to Read Error Codes
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Formerly Adam & Sam Brothers RepairMountlake Terrace · Furnace service
Gas and electric furnace repair in our home town of Mountlake Terrace
Our shop is on St Albion Way, so a cold house in Melody Hill or Cascade View is a few minutes from a van carrying igniters, sequencers and flame sensors. We repair first and bring up a new furnace only when repair stops making sense.
- Drive time
- 1–3 minutes off-peak; the shop itself is in town
- Heating mix
- About 64% of homes heat with electricity, 32% with gas
- Housing age
- Roughly 44% of homes were built from 1950 to 1969
- $85 diagnosticBecomes part of the repair price when you say yes. If you pass on the repair, that visit is all you pay.
- Up to $18 offAny repair requested through the online form. The diagnostic itself is never reduced.
- No-charge site visitInstalls are quoted in writing, equipment and installation work in one number.
In 1949, returning veterans moved into the first cinderblock homes built over a decommissioned World War II airstrip here, and plenty of those early houses still line the streets between 56th Ave W and Lake Ballinger. Census estimates put close to two in three Mountlake Terrace homes on electric heat, so the furnace we open in this city is as likely to be a cabinet of resistance coils and a sequencer as a gas burner. We fix both kinds, and because the van leaves from inside city limits, a technician can usually be in your hallway the same day when you call early, Monday to Saturday.
Our order of work never changes: find the fault, write the price down, and repair what broke before anyone mentions a new furnace. Limit switches, hot surface igniters, capacitors and heat relays all ride on the van, so a lot of local calls end with heat back on during that first stop. When a furnace really is finished, we quote a gas or electric replacement, or a heat pump paired with the furnace you already own, and the choice stays with you.
Furnace trouble we see most in Mountlake Terrace
Electric furnace blows air that is barely warm
- Likely cause
- One heat strip, or the sequencer that stages the strips, has failed
- What we do
- Meter every element and relay, replace the dead part, and check the wire lugs for scorching
The furnace breaker trips within minutes of a reset
- Likely cause
- A shorted element or a loose, overheated terminal
- What we do
- Find the short before power goes back on; a breaker that keeps tripping is a warning, not a nuisance
Gas furnace clicks and hums but never lights
- Likely cause
- Cracked hot surface igniter, or a pressure switch that will not close
- What we do
- Read the blink code, check the igniter's resistance, then test the inducer and vent path
Burner lights, then quits after a few seconds
- Likely cause
- Oxidized flame sensor or a weak burner ground
- What we do
- Clean or replace the sensor and confirm a steady flame signal before we pack up
Heat switches on and off every few minutes
- Likely cause
- A clogged filter tripping the high limit, or supply registers shut
- What we do
- Change the filter, test the limit, and measure temperature rise across the heat exchanger
A smell of gas near the furnace or meter
- Likely cause
- Possible leak; not something to wait out
- What we do
- Leave the house and call PSE at 1-888-225-5773 or 911 once you are outside; we return after the line is safe
What we find in Mountlake Terrace furnace closets
In the 1950s and 1960s houses around Cedar Terrace, Melody Hill and the streets off Cedar Way, the furnace is rarely the original. Most have been swapped once or twice, often into a narrow hall closet or a crawlspace, and the ductwork is frequently older than the equipment it serves. That combination shows up as high-limit trips, hot registers near the furnace and back bedrooms that never warm up. Before we condemn a part, we check filter size and static pressure, because a dusty one-inch filter jammed into a small return can make a healthy furnace look broken. The Lake Ballinger and Gateway areas mix older ramblers with newer infill, so two neighbors can own furnaces thirty years apart, and we load the van for both.
The condo and apartment buildings added in the 1970s and 1980s, and the Town Center mid-rises built since 2013, lean heavily on electric heat. Where a unit has a ducted electric furnace or air handler behind a closet door, the usual failures are a dead sequencer, a burned element or a tired blower capacitor. We work on the equipment inside your unit and note anything that belongs to the building so you can pass it to the manager. Access is the other variable: a furnace stacked above a water heater in a two-foot closet takes longer to service than one in a garage, and we tell you that up front rather than surprising you later.
Mountlake Terrace also sits inside the Puget Sound Convergence Zone, where north and south winds collide over the county line and wring out extra rain and the occasional surprise snow. The morning after the first real freeze of the season, our phone fills with no-heat calls from neighbors who have not run the furnace since spring, and dust-caked filters and stuck igniters account for a good share of them. Snohomish County PUD supplies the power here and PSE runs the gas mains; if you want a heat pump to take load off an electric furnace, we check which PUD programs apply when we write the quote. Premera's campus and the Link station keep the Town Center busy, but our trips to most houses here stay on local streets.
What furnace work costs in Mountlake Terrace
Furnace repair in Mountlake Terrace starts at $285, and most electric-furnace calls in town come down to a sequencer or a burned heat strip rather than anything structural. If the whole cabinet is worn out, a new electric furnace starts at $4,500, equipment and installation included. Treat these as starting points for our area rather than a quote; your exact figure goes on the written estimate after we diagnose. For a replacement, the visit to measure your home and the written quote cost nothing.
- Flame sensor cleaning or replacementfrom $285
- Furnace igniterfrom $285
- Limit switchfrom $285
- Pressure switchfrom $285
- Sequencer or heat relayfrom $285
- Electric heat strip / elementfrom $285
- Furnace or air handler control boardfrom $425
- Gas valvefrom $425
- Blower motor (standard PSC)from $475
- Inducer motorfrom $550
- Blower motor (ECM / variable speed)from $850
- Diagnostic visit$85, included in the repair
Starting prices for the north Seattle area, 2026. The $85 diagnostic is included in any repair you approve, and the exact price is in the written estimate before work starts.
System, installed
- Gas furnace, 80% AFUEfrom $4,750
- Gas furnace, 95%+ AFUEfrom $6,500
- Electric furnacefrom $4,500
- Heat pump outdoor unit onlyfrom $5,250
Install prices start here, equipment and installation included, before any utility program. Multi-zone systems are priced after a visit. We do not charge for the site visit or the written quote.
Fix the furnace or replace it?
An electric furnace has no burner and no heat exchanger to crack, so age alone rarely condemns one. A twenty-five-year-old unit with a dead sequencer is usually worth repairing. What shifts the math in an all-electric Mountlake Terrace house is the power bill: a heat pump outdoor unit tied into the existing furnace lets the strips sit idle through most of the winter, while the furnace stays on duty as backup. Gas furnaces get a harder look at age. Past roughly twenty years, an expensive part such as an inducer or a control board deserves a side-by-side comparison with replacement. A cracked heat exchanger ends the discussion, and we show you the camera image or combustion reading before we say so. Going from an 80% furnace to a 95% model also means new PVC venting and a condensate drain, which can be awkward in a hall closet, so that work is priced in the quote from the start.
Common questions
How fast can you reach a Mountlake Terrace house with no heat?
The shop sits near I-5 and the Town Center, and most addresses in the city are one to three minutes away when traffic is light. Reach us early in the day, Monday through Saturday, and a same-day visit is the norm. Tell us the model number from the furnace label and the blinking light pattern when you call, and we can bring the likely part on the first trip.
My electric furnace runs but the air is cool. Is it broken?
Probably partly. Electric furnaces heat in stages, and when one element or the relay that switches it fails, the blower keeps moving air while the house slowly loses ground. Check that the thermostat is set to heat and the breaker is on. Past that, leave the panels closed; the voltage inside is high, and a meter test is quick work for us.
Do you replace furnaces in condos and townhomes?
Yes, for the equipment inside your unit. Closet electric furnaces and air handlers are common in the town's 1970s and 1980s buildings, and replacing one is mostly about fit, wiring and circuit size. We check access before quoting, and the site visit for a replacement quote costs nothing. Anything shared by the building stays with your HOA or manager.
Is it worth adding a heat pump to my furnace?
In an electric-heated home it often is, because the heat pump carries most of the winter at a fraction of the electricity and the furnace becomes the backup. On gas the case is closer and depends on the furnace's age and whether you want summer cooling. We quote both paths and check which SnoPUD heat pump programs apply, without promising an amount.
What should I do if I smell gas near the furnace?
Do not flip switches or hunt for the leak. Get everyone out, then call PSE at 1-888-225-5773 or 911 from the sidewalk or a neighbor's house. PSE makes the line safe; after that, we can inspect the furnace, its gas valve and the connector and give you a written price for anything that needs repair.
Talk to Adam & Sam
Phone (425) 570-9520, or reserve a slot on our website and shave up to $18 off the repair bill. Approve the work and the $85 diagnostic is folded into it, while measuring your home for a replacement costs you nothing.
From Sam’s repair notes
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Schedule a repair
Request a visit from Adam & Sam
Send the basics and we call you back with an arrival window, most days the same morning.
- $85 diagnostic Becomes part of the repair price when you say yes. If you pass on the repair, that visit is all you pay.
- Up to $18 off Any repair requested through the online form. The diagnostic itself is never reduced.
- $10 off A second appliance’s diagnostic when we check it during the same trip.