What Hold Means on a Thermostat
Hold keeps the temperature you set instead of letting the schedule change it. It is not a lock on the furnace, and it is not a repair mode.
Hold is a schedule override. Programmable and smart thermostats change the setpoint through the day. Hold says: stop doing that, and keep this number. If the house is not matching the number on the screen, hold is probably not the broken part. The system still has to be able to heat or cool.
Temporary hold and permanent hold
A temporary hold usually lasts until the next period in the schedule, or for however many hours you set. People hit it on a day off and then wonder why the house set back at bedtime. That is the schedule returning, not a fault. A permanent hold, sometimes just labeled Hold, stays until you run the schedule again or clear it. Vacation and away modes are cousins of the same idea. They are still setpoints.
Fan Hold or a fan set to On is different. That runs the blower without a call for heating or cooling. The air can feel stale or cool and the equipment is not broken.
What hold does not do
- It does not bypass a safety switch, a float switch, or a tripped breaker.
- It does not turn Emergency Heat on. That is a separate mode on heat pumps.
- It does not make a system that is short of capacity suddenly keep up in a cold snap.
If you set 70, the room is 66, the mode is Heat, and nothing runs, the thermostat is asking and the equipment is not answering. Check that the mode is Heat and the fan is Auto, then look at a blank screen, a furnace power switch, or a breaker before assuming the schedule is haunted. More on a dead display is in the note on no power to the thermostat.
If the setpoint is right and the house never gets there, that is a heating or cooling diagnosis, depending on the season.
Common questions
Why did my hold turn off by itself?
A temporary hold is designed to end at the next schedule change. Switch to a permanent hold, or edit the schedule, if you want the number to stay.
Does hold make the system run all day?
No. The equipment runs when the room is off the setpoint and stops when it is satisfied, the same as a non-programmable thermostat.
The screen says Hold and the house is still cold.
Hold only locks the setpoint. If the system is not producing heat, the schedule is not the cause.
