According to the manual’s first page, the serial number label is on the right side of the chassis (you must pull the unit out of the wall sleeve slightly to see it).
| Flash Code | Meaning (According to the YWM15L-AMlDA Manual) | Likely Fix | | :--- | :--- | :--- | | | Normal operation (Standby) | No action needed. | | 2 Flashes | Pressure switch stuck open | Check condensate drain line or inducer motor. | | 3 Flashes | Pressure switch stuck closed | Replace pressure switch or check for obstructions. | | 4 Flashes | Limit switch open (Overheat) | Check airflow (dirty filter or closed vents). | | 5 Flashes | Rollout switch open (Flame rollout) | Serious issue. Check heat exchanger and flue. | | Continuous Flash | Control board failure | Replace the main circuit board. | york ywm15l-amlda manual
Operates on a standard 220-240V / 1 Ph / 50Hz power supply. According to the manual’s first page, the serial
: Installation should always follow local electrical and mechanical codes. Units should be inspected immediately upon receipt for any transit damage. Setia Air-Cond | | 3 Flashes | Pressure switch stuck
A: The York manual explicitly states: "Installation must be performed by a qualified, licensed HVAC contractor." Improper installation voids the warranty and is a fire/CO hazard.
Since the YWM15L-AMLDA is a commercial model, these manuals are rarely found on consumer shelves.