A.O. Smith BFM 50 Water Heater User Manual


 
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2.2 Turning the water heater on
2.2.1 Filling the water heater
1. Assemble the drain-off tap and check that it is closed.
2. Open the cold water tap to the water heater and open
all taps on hot water outlet points to vent them. The
heater is filled as soon as cold water pours out of
all outlet points.
3. Close all taps at hot water draining points. The
heater is now under water supply pressure. At
this pressure, the relief valve if fitted may not release
water.
2.2.2 Turning the water heater on
1. Check whether the water heater is filled with water
andwhether the gas pipe to the water heater is open.
2. Vent the gas pipe by opening the pressure gauge
nipple at the inlet side of the gas valve. Close the
pressure gauge nipple as soon as the gas pipe has
been vented.
3. Turn the temperature control knob fully to the left.
4. Turn on- the supply voltage by turning the main
switch. NOTE: if the frost-thermostat is calling for heat
the burner automation will immediately start its
ignition procedure.
5. Turn the ‘I/O’-switch on the column to the ‘T’
position. The control lamp in the switch will light.
6. Turn the temperature control switch to the desired
position, preferably position 3 (approximately 60°C).
The burner will ignite; the water heater will now work
automatically.
7. Check the standing pressure with a manometer
which can be connected to the pressure gauge
nipple. Check that the working pressure is set to the
correct level (see table page 10).
2.2.3 Setting up the pilot flame
The pilot flame has been adjusted in the factory and
does not have to be checked.
2.3 Turning the water heater off
For short periods:
1. Turn the temperature knob fully to the left and turn the
‘I/O’-switch in the ‘O’-position.
For longer periods:
1. Switch off the supply voltage.
2. Close the gas tap in the supply line.
3. Close the water supply tap.
4. If there is danger of frost, drain the water heater.
2.4 Usage/temperature control
The water temperature is controlled via the
temperature regulator. If the temperature in the water
heater falls below the set value, the temperature
regulator will call for heat. The burner automation will
operate firstly the ventilation fan for its purge cycle, then
a spark will ignite the pilot burner. The softlite control
then ignites the main burner.
The position of the temperature control knob
coincides with the following temperatures:
Position 1 = app. 40°C
Position 2 = app. 50°C
Position 3 = app. 60°C
Position 4 = app. 70°C
At high temperatures, more calcium precipitation is
caused in the water heater. Moreover, the standby-
losses of the water heater are greater with higher
temperatures. It is recommended to set the control-
thermostat at approximately 60°C. For reasons of
security, the water heater is provided with a high limit
and safety thermostats. The high limit thermostat is an
extra control set at 80°C and will operate in the event of
excess temperature within the water heater.
If the safety thermostat operates, the ‘RESET’ button
must be pressed after the water has cooled down. The
water heater will operate again in the usual manner.