Aprilaire 300 Owner's Manual page 9

CHANGE WATER PANEL INDICATOR
The control keeps track of humidifier operation time. The yellow
Change Water Panel light flashes after a preset amount of running
time has elapsed. This running time is preset by the installer based
on the humidifier model and water hardness.
Refer to the ANNUAL MAINTENANCE section for instructions on
changing the Water Panel or call your HVAC contractor for service.
TEST/RESET
The Test/Reset feature allows the humidifier operation to be checked
even if there is no call for humidity.
1. The HVAC system fan must be running for the humidifier to
function. Make a heat or fan call at your thermostat.
2. Set the knob to Test/Reset. Make sure the water saddle valve is
open and that there is electricity to the humidifier.
3. The humidifier will only operate for 1 minute in test mode.
4. Reduce the humidifier control setting to the recommended inside
RH, depending on the outside temperature. DO NOT LEAVE IN
TEST MODE AS HUMIDIFIER WILL NOT OPERATE AFTER 1 MINUTE HAS
ELAPSED.
ADDITIONAL INFORMATION
Your humidifier is a precision system that will accurately maintain the
RH in your home. For every 2°F change in outdoor temperature, the
Digital Humidifier Control will automatically adjust the indoor RH by 1%.
The Automatic Digital Humidifier Control will accurately control the
humidity in your home to a maximum of 45% RH.
The RH values in TABLE 2 are targets based on outdoor temperature
and the Automatic Digital Humidifier Control setting. The actual RH
may vary due to conditions in the home (cooking, showering, etc.).
TABLE 2: % RELATIVE HUMIDITY GUIDE
1
2
3
4
5
6
7
Outdoor Temperature (°F)
‑10°F 0°F
10% 10%
10% 10%
10% 15%
15% 20%
20% 25%
25% 30%
30% 35%
10°F 20°F
10% 15%
20%
15%
25%
20%
30%
25%
30% 35%
35% 40%
40% 45%
30°F 40°F
20% 25%
25% 30%
30% 35%
35% 40%
40% 45%
45% 45%
45% 45%
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