Hydraulic Schematic; Unvented Installations - Immergas Inoxstor 200 Installation, Usage And Maintenance Instructions

3.3

HYDRAULIC SCHEMATIC

Return
Flow
Cold
Water
Inlet
3.4

UNVENTED INSTALLATIONS

Failure to fit these essential safety devices will invalidate the warranty and create a dangerous installation.
This may lead to property damage, injury or loss of life.
Thermostatic control —
Energy Cut Out Device
Mixing Valve
Pressure Relief valve
Pressure Reducing
Valve
Expansion vessel
Backflow Prevention
Anti Vacuum Valve
Temperature and
Pressure Relief valve
(T&P valve)
Inoxstor Pre-Plumbed Water Heater
Flow Flow
Zone 1
Zone 2
Return Return
Zone 1 Zone 2
The in-built immersion heater contains a high limit thermostat which is factory pre-set to 60°C. This
should not be removed or bypassed.
A mixing valve must be installed. A thermostatic mixing valve limits the temperature of the delivered
water by mixing it with cold water as required. The delivered water temperature should not exceed
50°C.
This is the most important safety device. All unvented water heaters must be fitted with a Pressure
Relief Valve (Expansion valve) with a setting of 6 bars. The safety group includes a PRV. DO
NOT remove the safety group.
The cold water supply pressure must not exceed 3.5 bar. The safety group contains a PRV to reduce
pressure below this level. DO NOT remove the safety group.
Expansion must be accommodated using an Expansion Vessel. The Expansion vessel must be sized
to accommodate the maximum expansion of the system and should be suitable for use with potable
water. The size of the expansion vessel is proportional to the volume of the DHW system.
The size of the vessel should be carefully calculated. A rule of thumb for systems with a cold water
supply pressure of 3.5 bars and a maximum heating temperature of 60°C is that the volume of the
expansion vessel should be at least 10% of the total DHW system volume.
The included safety group contains a non-return valve to prevent backflow to the cold water supply.
DO NOT remove the safety group.
An Anti Vacuum Valve may be installed to ensure that the water heater is vented if exposed to an
internal negative pressure.
It is recommended to install a T&P valve. This ensures that the temperature of the stored water can-
not exceed 100°C by venting the water heater under these conditions.
Installation, Usage and Maintenance Instructions
6