This guide is for evohome owners with Honeywell Home HR92 radiator controllers. It uses the HR92 page and the evohome guides from Resideo, which makes Honeywell Home products.

What This Problem Means

Resideo gives the HR92 a two-year battery life and says a battery low reminder shows on the radiator controller screen. The evohome controller’s zone indicators also include Low Battery. The HR92 takes AA batteries, in a clip under its top cover.

Common Symptoms

• A battery low reminder on the HR92 screen
• A Low Battery indicator for the zone on the evohome controller
• About two years since the batteries went in

Safe Checks You Can Try

1. Confirm which controller is low

Check the HR92’s screen for the battery low reminder, and the evohome controller for a zone showing Low Battery.

2. Take off the top cover

Resideo’s installation steps show where the batteries go. First, remove the circular top cover.

3. Fit new AA batteries

Open the battery clip. Resideo’s guide names AA batteries; its text doesn’t give the number, so fit the same number you take out.

4. Close the clip and refit the cover

Close the clip and replace the cover.

5. Give it a few minutes

Resideo says battery devices only communicate with the evohome controller every four minutes to save power, so allow a few minutes for the controller to catch up.

The evohome user guide also has a section headed “Replacing the Radiator Controller (HR91 or HR92) batteries”, with diagrams: see Resideo’s evohome user guide.

The cover and clip steps come from Resideo’s evohome installation guide.

When To Contact Support

If none of these steps fix it, contact Resideo, which makes Honeywell Home products, through Resideo’s UK site.