warning Aprilaire

Error Code Yellow Steam Light

Indicates humidifier is operating below expected capacity, often due to low water conductivity or installation in soft water.

? What Causes This

Use of softened water or systems with short operation cycles leading to slower mineral conductivity build-up affecting steam production.

How to Fix It

Consider changing the water canister type; use blower activation features; install on higher conductivity supply if needed;

Source: page 27 of the official manual

From the manual

Manual page 27 — Aprilaire error Yellow Steam Light

This error code appears in:

Aprilaire 800