5
3.3 Installation options
This water heater may be used in open vented water heating systems or in an unvented installations.
When used in unvented installations, the appropriate unvented kit supplied by RVR must be used.
This contains items 1,3,4,5 and 6 as shown in figure 3. Other items such as mixing valves and zone
valves are also available from RVR.
3.3.1 Unvented installations
Please see figure 2 for a general layout for an unvented water heater installation. The following
safety devices must be fitted to the unvented water heater:
Thermostatic control — Energy Cut Out Device
The normal water storage temperature is 60° C. The water heater thermostat should be wired to en-
sure that the energy supply to the water heater is interrupted if the water temperature exceeds 60° C.
Temperature and Pressure Relief valve (T&P valve)
The T&P valve ensures that the temperature of the stored water cannot exceed 100
o
C by venting the
water heater under these conditions.
Figure 2 - Unvented System Schematic
Key
1 Anti Vacuum Valve
2 Mixing Valve
3 Tundish
4 Temperature & Pressure Relief Valve
5 Pressure Relief Valve
6 Expansion vessel
7 Non Return Valve
8 Check valve
