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Ideally, the fan speed setting should be sufficient for the heater to operate at full capacity, when all of the outlets are
open and balanced as described previously. The gas rate will then be maintained at the maximum rate during the
initial heating cycle, and will only decrease (modulate) the gas rate once the supply air temperature has been reached
on subsequent heating cycles. This will initially allow the heater to increase the house temperature at a faster rate
to maintain the customer’s desired temperature level.
So, with a floor outlet system, which usually requires a low fan speed, you may have to increase the thermistor
set temperature to achieve a 35º to 40º C rise and avoid modulation. If the heater still reaches the thermistor set
temperature or the rise is greater than 40º C, increase the fan speed.
With a ceiling outlet system, which usually requires a higher fan speed, it is unlikely the heater will reach the thermistor
set temperature and modulate. However, if it does, increase the thermistor set temperature and/or increase the fan
speed to achieve a 25º to 30º C rise and avoid modulation. If the temperature rise is above 40º C investigate the
reason:
• Small number of outlets on the system.
• Restrictive or poorly balanced ductwork.
• Oversized heater for the installation.
• Inadequate fan speed or thermistor set point.
Systems that have zone damper motors that are being operated from the Brivis Networker (Adaptive Zoning) will
require the zone minimum fan speed to be set to suit the duct system. This ensures optimum performance from the
Adaptive Zoning functions within the heater. To do this:
• Go to the Brivis Networker and close all but one zone. If the system does not have a common zone, leave only
the zone key that operates the least number of outlets turned ON (ensure this zone does not have less than the
minimum number of outlets required for the heater size). If the system has a common zone then all zone keys
can be turned OFF.
• Adjust the EHTG fan speed setting to provide the required amount of air from the remaining open outlets.
Ensure that the temperature rise does not exceed 45º C. Do not adjust the thermistor set temperature while
setting up the EHTG fan speed.
Final Checks (SP4, SP5, SP6 & BX5 Heaters)
• Check the temperature rise through the heater. The temperature of the warm air at any outlet should not be more
than 45º C above the return air temperature. If it is, the heater will be approaching an overheat situation.
• Check that the fan continues to run while the gas burner is operating.
• Check that the fan operates in fan only mode, by operating the Brivis Networker in fan only mode (see Owners
Manual).
• Ensure the required gas inlet pressure is supplied at all times during the heater’s operation (this should be with
all other gas appliances operating at the same time and at their full capacity).
• Go back to the Thermostat and press the ON/OFF button to turn the heater off.
• Ensure that the burners and fan turn off, then turn off the gas supply at the supply tap and remove the manometer
hose from the inlet test point on the gas valve.
• Tighten the inlet test point screw, turn on the gas supply at the supply tap and test for leaks using a soapy water
solution or leak detector spray.
• Replace the heater’s roof, and then proceed to instruct the customer on the correct operation of the system and
assist the customer with filling in the Warranty Card details enclosed in the Owner’s Manual.
• Issue any required documentation to the relevant people/authorities in regard to the installation of the heater, the
gas connection and power supply. For example, a Certificate of Compliance and Certificate of Electrical Safety.
Note:
Please assist the customer with filling in the Warranty Card Details in the Owner’s Manual or via the Brivis
website.
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