Honeywell Home THP2400A1080/U Large Cover Plate & J-Box Adapter for T-Series Thermostats

The THP2400A1080 is a thermostat cover plate from Honeywell Home.

Cover plates exist because the old thermostat was bigger. Replacing a wide mercury stat with a modern one leaves the paint line, the anchor holes and sometimes the whole opening on show, and the plate covers all of it in one piece.

Match the plate to the new thermostat, not to the old hole. Plates are cut for a specific series; one that does not register with the stat’s base leaves a gap on one side.

Worth measuring before ordering rather than after. The dimension that matters is the painted or papered outline the old stat left, not the thermostat that made it — twenty years of sun around a cover is a bigger rectangle than the cover was.

The alternative is patching and painting a wall to match a color that has aged. On a rental turnover or a multi-unit retrofit the plate is the cheaper answer by a wide margin, and it is done in the same visit.

• Brand: Honeywell Home
• Manufacturer Part #: THP2400A1080/U
• Type: Thermostat cover plate
• UPC: 194159007178
• Category: Thermostat Accessories