Honeywell Home · Current models

Honeywell Home RTH20B: programmable thermostat with no Wi-Fi

Honeywell's current entry-level programmable thermostat. It runs on two AA batteries, so it needs no C-wire, it's set from the buttons, and there's no Wi-Fi, app or account.

  • Needs app? No
  • Needs account? No
  • Needs Wi-Fi? No
  • Works fully offline? Yes

Why it is on the list

Honeywell's spec page lists no Wi-Fi, and the model runs on 2 AA batteries. Honeywell sells the X2S as the Wi-Fi ("smart") model of the X series; the X2P is the programmable model with no Wi-Fi. Listed at Home Depot.

Which X2P? According to Honeywell's installation guide, the RTH20B is single-stage (1 heat/1 cool) with 5-2 day scheduling only. The RTH21B and RTH22B add more schedule options, and the RTH22B supports 2 heat/2 cool conventional or 2 heat/1 cool heat pump systems.

Replaces: Home Depot's listing says the RTH20B is a direct replacement for the RTH2300B and a replacement for the RTH221B.

Won't work with: 120-240V electric baseboard heat (per the Home Depot listing). It's for 24V low-voltage systems.

Key specs (from the official spec page)

Thermostat type
Programmable
Program type (RTH20B)
5-2 day (per Honeywell installation guide)
Stages
1 heat / 1 cool, conventional or heat pump
Modes
Heat, Off, Cool, Auto
Alerts
Battery replacement, filter change
Display
LCD, backlit
Power
2 AA alkaline batteries
Size (H x W x D)
3.44 x 5.13 x 1.188 in
Warranty
1 year limited

Source: honeywellhome.com spec page
Home Depot listing (RTH20B/N). Last verified Oct 25, 2026. Manufacturers sometimes revise a model without changing its number, so check the source page before you buy.

Other verified options

See the full list: Thermostats with no Wi-Fi →