HVAC Services in Sammamish, WA
Sammamish has an unusual HVAC problem, and it comes from how quickly the plateau was built. Most of the housing went up inside a fairly narrow window, which means a large number of homes reached twenty years old at roughly the same time, and are now hitting furnace, water heater and air conditioning replacement together. If your neighbors all seem to be getting quotes at once, that is why.
This page covers what is specific to Sammamish: how the city handles permits, why Klahanie homeowners need to look in two places for their permit history, and which rebates apply here. To talk it through, call (206) 900-9231.
What we do most in Sammamish
Each service has its own page with the detail on equipment, sizing and what the work involves.
Heat pump installation
The natural choice on the plateau, because the ductwork is already there. A heat pump replaces the aging furnace and adds cooling on the same equipment rather than bolting on a separate air conditioner.
Also: Air to water heat pumps
Furnace repair and replacement
A lot of Sammamish furnaces are the originals and are now at the age where repair stops making financial sense. We will price a heat pump alongside a like for like furnace so you can compare them properly.
Also: All heating
Air conditioning
Original builder air conditioners are failing across the plateau. Replacement is straightforward where ducts exist, and worth weighing against a heat pump conversion that covers heating too.
Also: AC repair
Water heaters
The other thing reaching end of life all at once. Tank, tankless and heat pump models, and the heat pump versions need a reasonable volume of air around them, which rules out some tighter garages and closets.
Also: Heat pump water heaters · Tankless
Ductless and mini split systems
For bonus rooms over garages, finished basements and additions the original system was never sized to reach. One outdoor unit, one head per zone, no new ductwork.
Also: Mini split repair
Ductwork and air quality
Plateau homes often have one room that never keeps up. That is usually returns and duct sizing rather than an undersized furnace, and it is worth fixing at replacement time.
Also: Indoor air quality · Ventilation
Boilers and radiant heat
Less common here than in older parts of the Eastside, but they turn up in custom builds and larger properties. We service, repair and replace both, including radiant floors.
Also: Radiant heat
Geothermal
Ground source heat pumps need lot area for the loop field, which suits the larger Sammamish properties but not the denser plat developments. Tree rules are worth checking early.
Also: Heat pump options
Not listed? See every service we offer.
Klahanie: your permit history sits in two places
Klahanie is part of Sammamish, not Issaquah. Issaquah shelved its own annexation plan and transferred its annexation rights, and Klahanie became part of Sammamish effective 1 January 2016.
That has a practical consequence. Klahanie was developed between 1985 and 1994, so most of its equipment history predates the annexation. Anything permitted before January 2016 is a King County record rather than a Sammamish one, and searching Sammamish will show nothing. That does not mean the work was unpermitted. Anything from 2016 onward is a Sammamish record.
It also explains the timing. A neighborhood finished between 1985 and 1994 is now on its second round of equipment, which is exactly the age at which furnaces, water heaters and original air conditioners start failing in numbers.
Permits for HVAC work in Sammamish
| Permit authority | City of Sammamish Permit Center |
|---|---|
| Online only | The City states that “All permit applications are submitted online at www.mybuildingpermit.com”, the same regional portal used across the Eastside. |
| What needs a permit | Sammamish lists replacing a water heater or furnace among the projects that may require a permit, alongside removing trees and adding to a home. A straight equipment replacement is not automatically exempt here. |
| Project Guidance | Sammamish offers a free service called Project Guidance that returns property-specific code information before you apply. It is genuinely useful on the plateau, where plat conditions and critical areas vary street by street. |
| Trees | Tree removal is separately permitted, which matters when siting an outdoor unit or a geothermal loop field. |
| Electrical work | A heat pump or ductless conversion normally needs an electrical permit as well as the mechanical one. We hold a Washington electrical contractor license, so both come from us rather than a second trade. |
| Utility | Puget Sound Energy supplies gas and electricity in Sammamish, which is what determines the rebates below. |
We pull the permits on our own work. If one quote is noticeably cheaper than the others, it is worth asking whether permitting is included, because an unpermitted install is the kind of thing that surfaces later during a sale.
Rebates in Sammamish
Sammamish is Puget Sound Energy territory. The headline $1,500 conversion rebate requires your existing primary heat to be electric resistance, which rules out the many plateau homes on gas. A separate electrification rebate worth up to $4,000 covers moderate income customers converting from gas to an all electric heat pump.
PSE only pays when the installing contractor is a Recommended Energy Professional or Trade Ally, and NW Mechanical holds PSE Recommended Energy Professional status, so the work we install qualifies.
Our heat pump rebates page sets out every program side by side, including the conditions that disqualify people most often.
Where we work in Sammamish
The plateau looks uniform from the road, but the build date changes what you are dealing with.
Klahanie
Built 1985 to 1994, so equipment here is typically on its second round. Permit history before 2016 sits with King County rather than the City.
The central plateau
Later plats with existing ductwork and, often, an original builder air conditioner that is now failing. Heat pump conversions are usually straightforward.
Larger and custom properties
Bigger lots toward the edges, where zoning across wings and levels matters more, and where geothermal becomes worth discussing.
We also cover the rest of the Eastside and Seattle. See Issaquah, Redmond, Bellevue, Newcastle and all service areas.
Sammamish HVAC questions we get asked
Is Klahanie in Issaquah or Sammamish?
Sammamish, since 1 January 2016. Your permits go through Sammamish, and anything older than that is a King County record.
Do I need a permit just to swap a furnace?
Very likely. Sammamish lists replacing a furnace or water heater among the projects that may require a permit. We handle it as part of the job, and the City’s free Project Guidance service can confirm your specific property.
My air conditioner died and it is the original. Repair or replace?
If it is the builder original on a plateau home, it is likely at or past its service life, and parts for older refrigerants get expensive. That is the moment to look at whether a heat pump makes more sense, since it replaces the heating you will also need to change before long.
Everyone on my street is replacing at once. Does that affect lead times?
It can, particularly in the first hot week of summer. Planning a replacement in spring or autumn rather than during a heat wave is the single easiest way to get a better installation slot.
Will a heat pump keep up on the plateau in winter?
Yes. Sammamish sits a little higher than the lake cities but the design temperatures are still mild, and current cold climate heat pumps hold useful capacity well below anything the plateau sees.
Talk to us about your Sammamish home. We will look at the existing system, the duct capacity and the electrical service before quoting, and tell you honestly whether this is a repair year or a replacement year.
Call (206) 900-9231 or request an estimate.
Permit process and the online-only requirement from the City of Sammamish Permit Center. Klahanie annexation effective 1 January 2016 and the 1985 to 1994 development dates from public records. Rebate amounts and conditions from Puget Sound Energy. Permit rules and rebate amounts change, so confirm current requirements with the City and PSE before relying on them. Last reviewed September 2026.
Licensed, Bonded and Insured in Sammamish
Each license can be looked up individually on the Washington State L&I contractor register.
Mechanical permits here are issued by the City of Sammamish, and we pull them for the work we do. Natural gas and electricity are supplied by Puget Sound Energy.
If you ever smell gas, leave the building first and call Puget Sound Energy on 1-888-225-5773 before you call us.
