Homeowners hear three different numbers for the same Mitsubishi Electric system: 5 years, 10 years and 12 years. All three are real. Which one you end up with depends on three things: who installs the system, who registers it, and which indoor units you buy.
Here is how it works, based on Mitsubishi Electric’s current residential warranty documents (revision effective June 1, 2026).
The three levels
| Level | Parts | Compressor | What it takes |
|---|---|---|---|
| Base | 5 years | 7 years | Installed by a licensed contractor |
| Registered | 10 years | 10 years | Owner-occupied home, registered within 90 days of installation |
| Diamond Contractor | 12 years | 12 years | Owner-occupied home, installed and registered by a Diamond Contractor within 90 days |
Both extended levels last only while the original buyer still lives in the home. In California the warranty does not transfer when you sell the house.
The California rule most people miss
California residents get the 10-year level without registering. Mitsubishi lists California, Connecticut, Florida and Georgia as states where registration is not required for warranty benefits, though they still encourage it.
That rule stops at 10 years. The 12-year level still requires a Diamond Contractor to install the system and register it within 90 days. Registering it yourself later does not get you there.
The series that stop at 10 years
The 12-year level does not cover every Mitsubishi indoor unit. The HM, WR, HX and WX wall-mounted series have their own warranty document, and it tops out at 10 years parts and compressor, even with a Diamond Contractor install. That is not a reason to rule them out. You just should know which warranty you are buying before you choose between them and other wall-mounted lines such as the GS, GX, FS or FX.
We put the series and the warranty level on the written estimate, so it is never a surprise later.
What the manufacturer warranty does not cover
Labor. The Mitsubishi warranty covers parts and the compressor, not the time to diagnose and replace them. That is why the installer’s own workmanship coverage matters.
On a new installation we give a 2-year workmanship warranty. Extended labor coverage through JB Warranties is available for up to 12 years as a separately purchased plan, and we explain its terms before you decide.
What we do as a Diamond Contractor
We have been a Mitsubishi Electric Diamond Contractor since October 7, 2026. On every Mitsubishi system we install in an owner-occupied home, we register each indoor and outdoor unit within 90 days. You get the confirmation, and you do not have to remember a deadline.
If you are comparing quotes, ask each contractor two questions: will you register the system yourself, and which warranty level will this exact equipment carry? A quote that says “12-year warranty” on an HX or WX system is promising something the manufacturer does not offer.
Before you sign
- Ask which indoor series is on the quote, not only the outdoor unit.
- Ask who registers the equipment and when.
- Keep the registration confirmation with your home papers.
- If you plan to sell within a few years, know that the extended coverage ends when you move out.
Questions about a system you already have, or planning a new one? Read our Mitsubishi ductless FAQ, see Mitsubishi Electric installation and service, or call (925) 999-4095. The installation assessment is free.
Related questions
How do I book a visit or an installation assessment?
Need help with your system? Call (925) 999-4095 or book a visit. Repair diagnostics are $99, credited toward the repair. Installation assessments are free.
Further reading
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