If you're pulling a part number off a Daikin Applied board and you keep seeing it stamped or listed under "McQuay" or "Daikin-McQuay" instead, you haven't found the wrong part. You've found the same part, under three names that all point at one manufacturer's history.
Why one board has three names
Daikin acquired McQuay's applied HVAC business, and the product line carried its branding history forward. On our listings for Daikin Applied control boards, you'll see a line like this in the description:
"Also listed under: Daikin-McQuay [part number] | McQuay/Daikin [part number]"
Same part number, three labels. It's not three different boards that happen to look alike — it's one board that's been sold under legacy branding as the company name changed. Whichever nameplate is on the unit in front of you, the part number is what matters, and it's identical across all three names.
Real examples, checked against our own listings
Every one of these currently shows the same "Also listed under: Daikin-McQuay X | McQuay/Daikin X" line on its own page:
- 668105601 — MicroTech III WSHP Main control board
- 668105711 — MicroTech III WSHP I/O Expansion Board
- 668105901 — MicroTech III BACnet Comm Module
- 112026101 — MicroTech II I/O AUX Expansion board
- 060006101 — MicroTech II AAH Main board
Click through any of them and check the description — the alias line is right there, above the specifications table.
What this does not tell you
A shared name across three brands is not the same claim as a part superseding an older number. We keep those two ideas separate on purpose:
- Brand alias (what this article covers) — the same current part number, marketed historically under McQuay and Daikin-McQuay branding alongside Daikin Applied. No number changes; only the label does.
- Supersession (a different claim entirely) — an old part number that a manufacturer has formally replaced with a new one. That's documented differently, with a "Replaces" entry on the current part's page.
As of this writing, our Daikin Applied control board listings don't carry documented supersession data — no "Replaces" entries, no discontinued/replaced-by records. That's a gap in what we have on file, not a claim that Daikin Applied boards are never superseded. If you're holding an old Daikin, McQuay, or Daikin-McQuay control board number and it's not turning up in search under any of the three names, we don't have a documented cross-reference for it yet.
What to do if your number doesn't match
Send us the part number exactly as it appears on the board, plus the unit's model and serial number if you have them, through Request a Quote. A real person checks it against factory records rather than guessing from a resemblance between two similar-looking board numbers.
Where to look
Our full Daikin Applied control board stock — MicroTech II, MicroTech III, Mark IV, and BACnet communication kits — is in the Daikin Parts for Daikin Applied collection. For the broader picture of what we carry across Daikin Applied chillers, air handlers, and rooftop equipment, see Daikin Applied Replacement Parts: OEM Parts for Chillers, Air Handlers & Commercial HVAC.