Mitsubishi Electric Diamond Contractor | Seattle & Eastside
Diamond Contractor Installation, Service and Warranty Registration
Mitsubishi Electric Diamond Contractor in Seattle & the Eastside
NW Mechanical is a Mitsubishi Electric Diamond Contractor serving Seattle, the Eastside and south Snohomish County. That means a 12-year parts and compressor warranty on qualifying installs, plus two Mitsubishi offers running this fall.
Authorized Diamond Contractor
We install, service and register warranties on Mitsubishi Electric systems. Family owned since 1977.
MITSUBISHI ELECTRIC
Diamond Contractor
PSE RECOMMENDED
Energy Professional
WA STATE LICENSED
Bonded and insured
LOCALLY OWNED
Since 1977
Offers running now
Fall Rebate, through November 25. $750 off a qualifying Mitsubishi multi-zone system, or $1,050 to $1,450 on some models with a branch box. R454B equipment only, for homeowners. Installation and claim must be done by December 31, 2026.
Diamond Advantage, October 1 to December 31. One purchase on qualifying M-Series and P-Series systems that includes:
12-year parts
Parts and compressor warranty on a single-family install, once it's registered with Mitsubishi.
12-year labor
Labor coverage through JB Warranty at no extra cost.
12-year financing
One monthly payment through Synchrony, subject to credit approval.
We'll confirm whether your project qualifies before you commit.
The 12-year warranty
| Parts and compressor | 12 years, for a single-family home installed by a Diamond Contractor |
|---|---|
| Registration | Must be registered with Mitsubishi within 90 days of installation |
| Who registers it | We do, and we send you the confirmation |
| Labor | Not part of the standard warranty. Diamond Advantage adds it. |
Ductless or ducted
Many Seattle homes were built without ductwork. Mitsubishi's M-Series ductless systems heat and cool room by room without opening up walls. The P-Series covers larger homes and light commercial spaces. If your ducts are in good shape, a ducted heat pump may be the better fit.
Ductless and mini split systems
For homes without ducts, converted garages, bonus rooms and finished basements.
Heat pump installation
Uses your existing ducts to heat and cool with one system.
Mini split repair
Service and repair on existing ductless systems, including ones we didn't install.
Air conditioning replacement
Swap an older AC for a heat pump that heats and cools.
The other manufacturers we install
We also install American Standard, Bosch, Daikin, Day & Night, Midea, Navien and Lochinvar, and we service all makes and models whoever installed them. On the hydronic side we work with condensing gas boilers including Viessmann, Weil-McLain and Burnham, and with Uponor and Viega for in-floor distribution.
Mitsubishi isn't the right fit for every home. If another brand suits yours better, we'll recommend it.
Rebates and incentives
Heat pump rebates depend on your utility, mainly Seattle City Light in Seattle and Puget Sound Energy on the Eastside. PSE pays its rebates through approved contractors, and NW Mechanical is a PSE Recommended Energy Professional. What you qualify for also depends on your current heating and sometimes household income.
See our heat pump rebates page for details.
Common questions
Does the 12-year warranty apply automatically?
No. It needs a single-family home, a Diamond Contractor install and registration within 90 days. We handle the registration.
Do I have to finance to get the warranty?
No. The 12-year parts and compressor warranty comes with a registered Diamond Contractor install. Diamond Advantage adds labor coverage and financing on top. If you'd rather not finance, we'll quote the job without it.
Can I combine this with a utility rebate?
It depends on your utility and current heating. Some programs only pay through their own contractor lists, so we'll tell you upfront what applies to your address.
When do these offers end?
The Fall Rebate closes November 25, 2026, with install and claim by December 31. Diamond Advantage ends December 31, 2026. The 12-year warranty doesn't end with either one.
Talk to us about a Mitsubishi system. Call (206) 900-9231 or request an estimate.
Program details from Mitsubishi Electric. Terms and amounts can change. Last reviewed October 2026.
