A. O. Smith · Voltex AL Smart / Signature 900 Standard (HPTS, HPS10)

A. O. Smith Voltex AL Smart / Signature 900 Standard (HPTS, HPS10) error code 048

Battery low energy

What it means

Battery Low Energy.

How it shows: with an alert icon flashing (also flashing red LED)

Source: Hybrid Electric Heat Pump Water Heater Installation Instructions and Use & Care Guide, 100379659_2000812395, page 27

What A. O. Smith says to do

1. Make sure the battery protective tab has been properly removed from the battery tray, located on the left side of the Control Assembly. 2. Locate the battery tray on the side of the Control Assembly. 3. Remove the Phillips head screw, slide the battery tray out from the Control Assembly. 4. Remove the old battery and replace with a new Panasonic BR2032 or Murata CR3032 battery. 5. Reinstall the battery tray with new battery and hand tighten the Phillips head screw. NOTICE: If the Control Assembly was not connected via Wi-Fi, Bluetooth, or powered by a power source, the time will need to be set.

The manual adds: "These instructions are brief and intended as guidance for a qualified person. If you lack the necessary skills to perform these procedures call the Technical Assistance Hotline which is listed on the water heater's warranty sheet for assistance." (Hybrid Electric Heat Pump Water Heater Installation Instructions and Use & Care Guide, 100379659_2000812395, page 27)

Last checked 2026-10-03.

Safety first

WARNING! Working near an energized circuit can result in severe injury or death from electrical shock. (p.28)
WARNING! When you are finished, be sure all covers are secured to reduce the risk of fire and electric shock. (p.28)

From the manufacturer's manual for this series.

The same code on other models

Codes mean different things on different heaters. Match the series to the model number on your rating label.