York TMLX100C16MP11 furnace filter size
This furnace takes a 16 x 25 filter (side return) or a 20 x 25 filter (bottom return), depending on where the return air comes in.
The maker lists width and height only. Most filter racks next to a furnace hold a 1-inch filter; a separate filter cabinet usually holds a 4- or 5-inch one. Check the thickness printed on the edge of your old filter before you order.
Every filter option for this model
Where the filter goes
external to cabinet: field-supplied side-return rack and/or bottom-return rack, or filter at a return grille; not supplied
The maker does not ship a filter with this furnace. The size above is the maker's recommended size at the furnace; if your home has a filter grille in a wall or ceiling, that grille sets the size instead.
How often to change it
General guidance, not from the maker's table: 1-inch filters every 1 to 3 months; 4- and 5-inch filters every 6 to 12 months. Change sooner with pets, smoking or construction dust.
About this model
| Cabinet width | 21 in. |
|---|---|
| Airflow direction | multi-position (upflow/downflow/horizontal); TMLX = low NOx |
| Heat input | 100,000 BTU/hr |
| Efficiency (AFUE) | 80% |
| Model number note | trailing revision digits/letters vary |
How to read a York model number
Source
- York TM8X Technical Guide 445348-YTG-G-0616 (technical guide (spec sheet), page 3): document. Read 2026-11-03.
- York TM8X Installation Manual 437642-UIM-C-0210 (installation manual, page 9): document. Read 2026-11-03.
Check that the model number on your furnace label matches, and compare with the size printed on your old filter. If they differ, go by the filter that fits your rack.