37 boiler installers filed 428 boiler permits on homes in the City of Seattle from October 2023 to September 2026; 19 filed one in the last 12 months. The middle filed job value was $15,000. The most active in the last 12 months were Northwest Mechanical (40 permits), Carlson Mechanical (36) and Greenwood Htng & Home Services (24); busy is not the same as careful. Side by side: permits filed, share finished, license status and permits in the last 12 months for each firm. Pick what you value and the list re-orders.
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Top 5 by boiler permits filed in the last 12 months. This is volume, not quality: a busy firm is not necessarily a careful one.
The 8 ZIP codes with the most boiler permits on homes from October 2023 to September 2026. Each opens permits by trade and the most active firms there.
98112 (64) 98103 (41) 98122 (38) 98102 (30) 98115 (30) 98144 (29) 98199 (24) 98105 (23)
Before you move a slider, the list is in a default order built only from the permit record: how much of each firm’s record is this kind of job (weight 30), how often its permits reached completion (25), how many permits it filed in the last 12 months (15) and how quickly its permits closed (10). Each measure is ranked against the other 37 firms and pulled toward the middle when a record is short; a firm with a matched license problem is listed last.
The order comes from the Seattle permit file, not from reviews: 19 of 37 boiler installers filed a permit in the last 12 months and 92% of their permits a year or more old were finished. Nobody pays to be listed or to move up, and there are no star ratings or reviews. The sliders and presets change the weights, and the order changes with them. How the records work in Seattle.
We do not rate contractors. In this page’s default order, which uses only the permit record through Sep 2026, the top 3 are Carlson Mechanical (73 permits, 99% finished), Greenwood Htng & Home Services (61 permits, 96% finished) and Northwest Mechanical (107 permits, 96% finished). By permits filed alone, the most active is Northwest Mechanical with 107.
37 firms are on the list; the busiest filed 40 boiler permits in the last 12 months and the middle firm filed 2 in the whole file. Line them up on the same public measures: permits filed, share of permits finished, usual filed job value and license status. Pick what matters to you and the list re-orders, for example recent activity if you need someone soon. The order comes from the permit record only, and nobody pays to be listed or to move up.
37 firms filed at least one boiler permit on homes in the City of Seattle from October 2023 to September 2026; 19 of them filed one in the last 12 months.
32 of the 37 boiler installers on the Seattle permit file match an active license, 2 match one that is expired, suspended or inactive, and 3 we could not match. A firm we could not match is not proven unlicensed: the match is by company name. Look any firm up by name or license number with Washington L&I contractor lookup; statuses show under each firm’s name above. How to check a contractor's license in Washington →
Three you can check against this page: “How many boiler permits have you filed in Seattle?” (the middle firm here filed 2; 19 of 37 filed one in the last 12 months); “What value will you put on the permit?” (the usual filed value here is $15,000); “Will you pull the permit in your company’s name, and when is the final inspection?” (92% of older boiler permits here were finished). All 10 questions and how to check each →
On this page: 37 firms filed 428 boiler permits from October 2023 to September 2026, and each firm’s name opens its own permit record. Every number comes from City of Seattle (SDCI) building, trade and electrical permits on single-family and duplex homes (the city's open-data exports). To see one permit itself, search the address or permit number with the Seattle permit office. How the records work in Seattle →
We do not rate or collect reviews. Instead each of the 37 boiler installers here is shown with its permit record: 428 permits, the share finished, usual filed value and license status. Read reviews on other sites and use this page to check them against the record. Reviews vs permit records →
Every number on this page comes from City of Seattle (SDCI) building, trade and electrical permits on single-family and duplex homes (the city's open-data exports): 37 firms filed 428 boiler permits on homes in the City of Seattle from October 2023 to September 2026, and 19 of them filed one in the last 12 months. The middle firm has 2 permits in the whole file. A short record leaves more uncertainty, and some jobs never require a permit.
The middle recorded permit value is $15,000. That is a filed estimate, not a quote or final bill. See how we compare records.
Most Seattle boiler permits are filed in January (149 against an average month of 100); August is the quietest (50). When each trade is busiest in Seattle →