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

1.5) DELIVERY 

Upon delivery of the boiler, check the nameplate to be 
sure that you have received the model with the correct 
rating and proper voltage. 
 

The following items are supplied with the unit: 
-  A pressure relief valve, adjusted to 30 psi; 
-  A drain valve; 
- A 

½

"

 NPT to 

⅛

"

 NPT reducer for the installation of an air 

purge valve; 

-  Modulating outdoor sensor. 

1.6) INSTALLATION

WARNING 

The installation of this unit must be performed by 
a qualified technician and it must conform to the 
standards and regulations in force as well as the 
Canadian Installation Code for Hydronic Heating 
Systems CSA B214-01. 

1.6.1)  Positioning and clearances 

The unit must be installed in an area that is dry, non-
corrosive, without excessive dust, well ventilated and where 
the ambient temperature does not exceed 27°C (80°F). 

The boiler can be installed directly on a wall, by way of the 
mounting plate, supplied with the unit.  Ensure that it is 
installed level and that the clearances indicated below are 
respected (Table 1). 

TABLE 1 

MINIMUM CLEARANCE 

        LOCATION 

      CLEARANCE 

Access side to elements 

   0.41 m (16") 

Other side 

15.24 cm (6") 

Above 

15.24 cm (6") 

Front 

   0.61 m (24") 

Back 0" 

1.7) DISTRIBUTION 

SYSTEM 

The proper functioning of your heating system is directly 
related to the quality of the plumbing installation.  Therefore, 
the entire installation must be performed by qualified 
technicians. 
 
See Figure 3, p. 11 for the functions of the various boiler 
connections. 
 
The heating system must be set-up to operate at a maximum 
pressure of 28 psi and the operating temperature may range 
from 32

˚

C to 99°C (90

˚

F to 210°F). 

Freeze protection (when required) 

WARNING 

Only propylene glycol may be used in this 
hydronic heating system, to prevent freezing. 

It is recommended to add a maximum of 50% of 
propylene glycol mixture to ensure proper 
operation. 

Do not use automotive anti-freeze, ethylene glycol 
or any undiluted anti-freeze. 

If the above recommendations are not followed, 
severe personal injury, death or substantial 
property and/or equipment damage can result.

All installations must include the following items: 
a.  1 pressure regulator, adjusted to 12 psi, installed 

between the boiler and the main water supply in the 
building; 

b.  1 expansion tank, pre-pressurized to 12 psi and of 

appropriate size; 

c.  1 or more automatic air purge valves; 
d.  1 or more circulating pumps of appropriate capacity. 

CAUTION 

To avoid water damage and/or scalding due to relief 
valve operation, a discharge line must be connected to 
the valve outlet and run to a drainage area.  The 
discharge line shall be installed in such a way that it 
will allow for the complete drainage of the valve and 
the discharge line. 

1.8) 

INSTALLATION OF THE BOILER 

At the time of installation, the following steps should be 
followed.  Refer to Figures 3 and 4, p. 11 and 12 for 
additional information. 

1. 

Choose an appropriate location.  Mount the boiler 
securely on the wall, with the help of the mounting plate.  
Ensure that it is level and that the minimum clearances 
are observed; 

2. 

Install the drain valve and the safety valve as indicated 
in Figure 3; 

3. 

An air vent can be installed on the unit.  In such case, 
use the ½" NPT to 

⅛

" NPT reducer, which is provided; 

4. 

Install the water supply and and return piping with the 1"  
NPT fitting; 

5. 

The heating supply line must include: 

a.  1 circulator along with 2 maintenance valves; 
b.  1 automatic pressure reducing valve adjusted to 

12 psi, with a shut-off valve on the return water 
line; 

c.  1 expansion tank; 
d.  1 automatic vent. 

4