MRCOOL® DIYCOUPLER-1412K75C — DIY 4th/5th Gen Coupler Set (1/4″ + 1/2″) with 75ft DIY Pro Cable for 9K, 12K & 18K

MRCOOL® DIYCOUPLER-1412K75C — Line Set Coupler Kit with 75 ft DIY Pro Cable

DIYCOUPLER-1412K75C lets you link two MRCOOL DIY quick-connect line sets together when one set is not long enough to reach the condenser. The kit includes a 1/4″ coupler, a 1/2″ coupler, and a 75-foot DIY Pro Cable to cover the longer electrical run in the same purchase.

Key features

• One coupler set — 1/4″ liquid line coupler plus 1/2″ suction line coupler, machined brass
• 75 ft DIY Pro Cable included — factory-terminated, replaces the 25 ft cable that ships with the condenser
• Quick-connect design — mates to MRCOOL DIY flare fittings by hand, no brazing and no vacuum pump
• For 6K, 9K, 12K and 18K indoor units — the capacities that use 1/4″ x 1/2″ lines
• Both generations supported — compatible with 4th Gen R-410A and 5th Gen R-454B DIY systems
• Pairs with 16, 25, 35 and 50 ft line sets — combine two sets in any mix up to the length limit

Line length limit

MRCOOL specifies a maximum of 75 feet of total line length per zone. A 25 ft set joined to a 50 ft set reaches that limit; a 35 ft set joined to a 50 ft set exceeds it. Plan the run before ordering.

What is in the box

• 1 × DIYCOUPLER-14 (1/4″ coupler)
• 1 × DIYCOUPLER-12 (1/2″ coupler)
• 1 × 75 ft MRCOOL DIY Pro Cable

Frequently asked questions

Do I lose refrigerant when I add a coupler?

The couplers use the same self-sealing quick-connect design as the line sets. Follow the MRCOOL torque specifications and leak-check every joint after assembly.

Can I use this on a 24K or 36K indoor unit?

No. Those capacities use 3/8″ x 5/8″ lines and need DIYCOUPLER-3858K75C instead.

Why is a longer cable included?

Extending the refrigerant run also extends the electrical run. The 25 ft cable supplied with the condenser will no longer reach, so the 75 ft DIY Pro Cable takes its place.

Can I join three line sets together?

No. MRCOOL supports a single coupled joint per zone, within the 75 ft total length limit.

Will this work with my 4th Gen R-410A system?

Yes. This coupler kit is listed as compatible with both 4th Gen R-410A and 5th Gen R-454B DIY equipment.

Why buy from Cedars HVAC

• Genuine MRCOOL OEM parts — never aftermarket substitutes
• Contractor-friendly pricing on every line set and accessory
• Fast nationwide shipping direct from the distribution center
• Financing available at checkout

Shipping and returns

Most orders ship the same or next business day direct from the distribution center. Standard ground shipping covers the continental United States, and expedited options are available at checkout. Returns are accepted within 30 days on unopened, uninstalled parts — see our return policy for full details.