Wiser thermostat: Red flashing for 5 seconds every minute
The batteries are critically low: replace them immediately. The Wiser Home app also sends a low-battery alert.
Applies to: Wiser Radiator Thermostat. What you see: a light.
What Drayton Wiser says to do
- Fit 2 × 1.5 V AA (IEC LR6) alkaline batteries; Drayton says rechargeable batteries should not be used.
- You can check battery status at any time in the Wiser Home app, under Devices in the Settings menu.
Source
Drayton Wiser’s own help page, read on the date shown.
- Drayton Wiser: How to Change Batteries in Wiser's Smart Radiator Thermostat — Wiser Radiator Thermostat. wiser.draytoncontrols.co.uk Checked 2026-09-29.