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Shop in Mountlake TerraceMon–Sat 8 AM–7 PM · Sunday closed Book online: up to $18 off the repair
LarchHVAC & Appliance (425) 570-9520
Sam with a newly installed mini-split outdoor unitFormerly Adam & Sam Brothers Repair

Ductless heat pumps

Ductless mini-splits: install, repair, deep clean

For a baseboard-heated rambler, a hot upstairs bedroom or a condo with no ducts, a ductless heat pump heats and cools without a remodel. We install them, repair them and take the indoor heads apart for a proper cleaning.

  • $85 diagnostic, included in the repair
  • Same-day visits Mon–Sat
  • 5.0 on Google
  • $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.

A large share of homes north of Seattle were built without ducts. The 1950s and 60s houses in Mountlake Terrace and Shoreline, many 1970s split-levels around Lynnwood and Edmonds, and countless condos heat with electric baseboards or wall heaters, and almost none of them had air conditioning until the summers changed. After the June 2021 heat dome, ductless heat pumps started appearing on side yards and balconies all over the area. A single outdoor unit connects through a small wall opening to one or more indoor heads, each heating and cooling its own room, and in our mild winters a modern inverter unit carries the heating load on all but the rarest cold nights. Condo owners like them because the outdoor unit can sit on a balcony or a wall bracket, though many associations want to review the plan first.

Mini-splits have a weak spot that shows up fast in a damp climate: the indoor head. Its coil and blower wheel stay wet during cooling and pull in dust and kitchen grease year round, so after a few seasons many develop a musty smell, black specks on the louvers or drips down the wall. Cooking grease and pet hair speed up the buildup, and so does running the system in dry or cool mode through most of the summer. A filter rinse does not reach that. Deep cleaning means taking the head apart, bagging it and washing the coil and blower wheel until the water runs clear. The rest of our mini-split work is repair: fan motors, control boards, condensate pumps, and refrigerant leaks at flare connections, handled by our own technicians under EPA Section 608 rules.

Mini-split problems and their causes

  • Musty or sour smell when the head starts

    Likely cause
    Mold and biofilm on the blower wheel and coil
    What we do
    Take the head apart, deep clean it, flush the drain line
  • Water dripping from the indoor head

    Likely cause
    Clogged drain line, failed condensate pump, or a dirty coil overflowing the pan
    What we do
    Clear the line, test the pump, clean the coil and pan
  • Blinking lights on the head, no heat or cooling

    Likely cause
    Fault from a sensor, board, fan motor or the communication wiring
    What we do
    Read the code, test the named part, repair or replace it
  • Weak heating or cooling, frost at the outdoor service valves

    Likely cause
    Low refrigerant from a flare leak
    What we do
    Find the leak with instruments, remake the joint, evacuate and recharge
  • Indoor fan noisy, wobbling or not spinning

    Likely cause
    Blower wheel caked with debris, or a failing fan motor
    What we do
    Clean or rebalance the wheel, replace the motor
  • System runs, but one room never gets comfortable

    Likely cause
    Undersized head, poor placement or a zone fault on a multi-zone system
    What we do
    Measure the room load and airflow, recommend adjustments or added capacity

How we install and repair ductless systems

An install begins with a visit to measure rooms, look at windows and insulation, and choose the right wall for each head and a solid spot for the outdoor unit. Sizing matters more than with ducted systems: an oversized head short-cycles and leaves rooms clammy, while the right size runs low and steady. On install day we mount the heads and the outdoor unit, run and insulate the line set and condensate drain, pressure-test with nitrogen, pull a deep vacuum confirmed on a micron gauge, and adjust the charge for the line length. Line sets and drains are routed to look tidy outside, with a cover where the run is visible and a steady slope on every drain so water never pools. We install and service Mitsubishi, Fujitsu, Daikin, LG and Bosch equipment.

Repairs start with the fault code, which most brands flash on the indoor head or display on the outdoor board. We test the sensor, fan motor or board the code points to, check the communication wiring between units, and measure refrigerant pressures only when the symptoms call for it. Common fan motors, sensors and condensate pumps ride on the van. Units from the early 2010s may need boards or motors that are harder to find, and then we tell you the lead time and whether a newer system is the better use of the money. Utility support differs by address: Snohomish County PUD, Seattle City Light and Puget Sound Energy each set their own heat pump programs, and we check which ones, if any, apply to your system when we quote.

Charging a heat pump outdoor unit with refrigerant

Mini-split starting prices

Mini-split repair and cleaning start at $285; deep cleanings and drain clearing are the common visits, while leak repairs with a recharge, fan motors and control boards make up the rest. A complete single-zone ductless heat pump starts at $4,000, equipment and installation included, with each added zone priced on top; multi-zone systems are quoted on request after we see the rooms. The repair and cleaning figure marks where our prices begin locally, not a quote; the exact number is set in writing once we have diagnosed the head. The install site visit and its written quote cost nothing. Every cleaning includes a check of the drain and filters so the head stays fresh longer.

See all prices

  • Mini-split deep cleaning (per indoor head)from $285
  • Mini-split fan motorfrom $375
  • Mini-split control boardfrom $475
  • Mini-split leak repair and rechargefrom $550
  • 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

  • Ductless mini-split, single zonefrom $4,000
  • Each added mini-split zonefrom $2,250
  • Multi-zone mini-split systemsOn request

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.

From Sam’s repair notes

Common questions

How often should a mini-split be deep cleaned?

It depends on use and the room. A head in a bedroom that mostly heats may go a few years; one in a kitchen, or one that cools all summer, may need it every year or two. Rinse the filters monthly in heavy-use seasons. A musty smell at startup, black specks on the vanes or drips are the signs it is due.

Can one outdoor unit serve several rooms?

Yes, a multi-zone outdoor unit can feed two to five or more indoor heads. It saves wall and yard space, but every head then depends on one compressor, and small rooms can end up oversized. Sometimes two single-zone systems work better. We look at the floor plan and quote multi-zone systems on request.

Will a mini-split heat my house through a cold snap?

Modern inverter units keep producing heat well below freezing, and our lowland winters rarely test that limit. A home with one head may still have cool back rooms, since heat does not travel well past closed doors. Many owners keep baseboards in bedrooms as backup. We size the system for your rooms and point out where backup heat helps.

My mini-split is blinking and stopped. What should I do?

Note how many blinks and which light is flashing, then switch the unit off at its breaker or disconnect for a few minutes and restart it. If the code returns, call us with the pattern and the model number, or put both in the booking form. Many codes point to a specific sensor or fan, which helps us bring the right part.

Do you repair mini-splits you did not install?

Yes. We service most major brands no matter who installed them. If we find installation problems, such as a drain line without slope, leaking flare joints or a missing disconnect, we explain them and include the fix in the written price so you can decide.

Talk to Adam & Sam

Musty head, dripping wall or a room that will not cool? Call the shop, or book online and repairs come with up to $18 off. The $85 diagnostic is part of any approved repair, and the site visit for a new ductless system costs nothing.

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.

Requests sent from this form get up to $18 off the repair. The $85 diagnostic stays the same and is folded into any repair you approve.

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