Honeywell Programmable Room Thermostat T4R 7 Day Y4H910RF4003

The Honeywell Y4H910RF4003 is a 7 day programmable room thermostat from the Honeywell T4 range of residential heating controls. It is a temperature control device that lets the user set daily heating schedules and a target room temperature, then signals the heating system to run accordingly. It is listed by Honeywell under the part type Temperature Control - T4 Effortless.

• The heating does not come on when the thermostat calls for heat, or runs continuously regardless of the set temperature.
• The display is blank, flickering or unresponsive to button presses.
• The room temperature reading is clearly out of step with the actual room temperature.
• Time and programme settings are lost or reset after a power interruption.
• The thermostat no longer follows its stored schedule, or schedules cannot be edited.

• Confirm the part number printed on the existing thermostat matches Y4H910RF4003 before ordering.
• Check the appliance model against the compatibility list below to confirm the control is the correct fit.
• Note that the alternative number 4201227 may appear on older labelling or documentation for the same control.