Walter Wilson HYDRA Series, Installation Instructions And Homeowner'S Manual

SECTION 2 

OPERATION 

2.1) 

ADJUSTMENTS AND START-UP 

CAUTION 

The boiler must be filled with water and all air purged 
from the system, before turning on the power. 

If the power is turned on before the boiler is filled with 
water, the elements will become seriously damaged. 

1. 

With the help of a small screwdriver, adjust the boiler 
temperature screw on the board potentiometer located 
on the control board, to between "90°F - 120°F - 150°F - 
180°F - 210°F" (see Figure 1, item B); 

2. 

In the event that the modulating capacity feature of 
the boiler is desired,

 an outdoor sensor will need to be 

installed and wired onto the Hydra electronic board 
(terminals S1 and S2). Once the outdoor sensor is wired 
to the board, the boiler capacity will modulate if the 
outdoor air temperature is between -10

˚

C (14

˚

F) and 

10

˚

C (50

˚

F) (see figure 2, p. 9 for more details on 

modulation).  If capacity modulation of the boiler is not 
required for the application, do not proceed with the 
installation of the outdoor sensor and leave the 
terminals S1 and S2 unwired. 

3. 

Check if the dip switches "NUMBER OF ELEMENTS" 
are in the proper position. Refer to Table 2 and Figure 1, 
item D to determine the position of the dip switch, based 
on the power rating; 

4. 

Turn on the power; 

5. 

Adjust room thermostat according to the required 
temperature. 

TABLE 2 

DIP SWITCHES POSITION 

Dip switch 1 

Dip switch 2 

Dip switch 3 

New Hydra with 

immersed 

sensor 

OFF ON  ON 

Number of 

elements 

Dip switch 4 

Dip switch 5 

3 OFF 

OFF 

4 OFF ON 
5 ON 

OFF 

6 ON ON 

Dip switch 6 

Dip switch 7 

Dip switch 8 

Not used 

OFF 

OFF 

OFF 

FIGURE 1 

HYDRA ELECTRONIC BOARD 

A: BOARD TERMINAL STRIP 
B: POTENTIOMETER 
C: TROUBLESHOOTING PORT 
D: DIP SWITCHES FOR BOARD CONFIGURATION 
E: FUSE 2A (AUTO-RESET) 

2.2) CHECKING 

THE 

CONTROLS 

Operational Controls 

After having made sure that the boiler is completely filled 
with water and that there is no call for heat, turn on the 
power to the unit. 

For this verification, disconnect the outdoor sensor from the 
S1 and S2 terminals of the Hydra electronic board. As a 
result, all the elements will remain functional, regardless of 
the outside temperature; 

Set the thermostat in the house to 30°C (85°F). The 
circulator should start-up and the elements should start 
sequentially, one by one (randomly), at approximately 15 
second intervals. Pilot lights located on the control board 
provide a visual check of the operation of the boiler; 

The circulator stays on for as long as there is a call for heat; 

By observing the temperature indicator, allow the water 
temperature to rise to 60°C (140°F). Then, turn the electronic 
Limit Control counter clockwise to 32°C (90°F). The 
elements will stop sequentially, one by one, at 1 second 
intervals between each. Now, the water temperature must be 
adjusted with the "90°F - 120°F - 150°F - 180°F - 210°F" set 
screw on the electronic board. 

Once the verification is completed, reconnect the outdoor 
sensor to S1 and S2 of the Hydra electronic board (if 
required). 

6