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17 - MAINTENANCE
17.9 - Draining the water
from the heater
To drain the water from the unit, follow the steps
below:
1. turn the power off to the heater;
2. close the manual gas shutoff valve, Figure 14-1;
3. wait until the water temperature decreas below
104°F (40°C);
4. close the heater isolation valves. If isolation
valves haven’t been installed, the entire system
will have to be drained;
5. connect a hose to the drain valve item “2” of
Figures 3-3 and 3-6 or item “5” directed on the
item “12” of Figure 8-5 and place the other end of
the hoses in a sink or some other suitable drain;
6. open the drain valves and wait for all water to
drain;
7. if unit isolation valves have not been installed,
open any bleed valves at the highest point of the
system;
8. after draining out all the water, close the bleed
valves and the unit drain valves.
NOTICE!
The heater cannot be drained completely
of water without purging the unit with an air
pressure of 60 psi.
Proceed as follow:
1.- completely drain the water as per steps above;
2.- remove circulator pump “A” or “E” (Figure 8-4);
3.- spray 50 PSI compressed air in connection “C”
to drain the water from inner heat exchanger.
17.10 - Water and flue
temperature sensor
The heater has a number of sensors that measure
temperature. The electrical resistance between
the sensor wires must correspond with the values
shown in Figure 17-14.
Figure 17-14
Water and flue temperature sensors’
curve
Summary of Contents for Esteem 399
Page 3: ...3 SAFETY INSTRUCTIONS ...
Page 5: ...5 SAFETY INSTRUCTIONS ...
Page 112: ...112 17 MAINTENANCE ...
Page 116: ...116 19 SPARE PARTS Spare parts ...
Page 135: ......
