CTM CT-12HN – 12,000 BTU Marine Air Conditioner 230V 50/60HZ NMEA2000

A failing 12,000 BTU compressor rarely announces itself quietly — it starts as a hum that’s a little off, then a unit that runs constantly and still can’t quite hold the cabin temperature it used to. The CTM CT-12HN replaces that kind of aging 230V system with titanium coils, NMEA 2000 connectivity, and a documented cross-reference to the Dometic DTG12 and comparable OEM units, so the swap doesn’t turn into a full rewiring job.

Why Choose the CTM CT-12HN

This model is a documented replacement for the Dometic DTG12 (part 205162129), DTU12 (205162120/205162121), Cruisair STX12/STQ12, and equivalent Marine Air, Marinaire, Flagship, and Webasto 230V 12K units. That matters most when you’re swapping a failed system and want to reuse existing ductwork and wiring rather than re-engineer the install from scratch.

This unit needs 230V shore power or generator capacity to run — it’s not the right fit for boats limited to 115V. For those, the CT-12N (same BTU rating, 115V input) is the correct counterpart.

What to Know Before Installing

• Pairs with the CTM PM500LH pump, matched to this unit’s water flow requirements
• Fuse sizing must stay within the 10–15A range specified for the unit to operate safely under load
• Return air grille needs at least 130 sq in of clearance for proper airflow
• NMEA 2000 setup is more straightforward with a technician familiar with your specific MFD brand, since configuration varies between Garmin, Raymarine, and other systems