Sealed Primary Systems - Heatrae Sadia ELECTROMAX Installation & Servicing Instructions Manual

3.5 Sealed Primary Systems

The Electromax boiler must be installed in a
sealed primary system. All necessary primary
system controls are supplied fitted to the
Electromax. The sealed system expansion
vessel fitted has a capacity of 12 litres which, as
a general guide, will be suitable for a heating
system of up to 107 litres. If in doubt the total
primary system volume must be calculated to
determine if additional expansion volume is
required.
The Electromax initial primary system cold fill
pressure is 1.0 bar. The expansion vessel size =
0.11 x the total system volume. The boiler and
pipework within the Electromax hold approx.
2 litres of water, therefore additional system
expansion volume will only be necessary for
systems that exceed 107 litres.
The Electromax boiler
automatic air vent at its highest point (fitted
to the pump housing, see diagram 6, page
11). If any primary pipework is routed above
the level of the Electromax additional air vents
must be fitted to the highest points of the flow
and return pipes and at any point where air is
Primary System
Expansion Vessel
Primary System
Pressure Relief
Valve
Automatic
Bypass Valve
Primary
Flow
Primary
Isolating
Return
Valves - to Radiators
or Undefloor System
Diagram 6 System Schematic - Primary Circuit
Diagram 6 System Schematic - Primary Circuit
likely to collect.
An automatic bypass valve is fitted to the
Electromax to allow thermostatic radiator
valves to be fitted to the system.
incorporates an
Automatic
Air Vent
Circulating
Pump
Electric Boiler
Filling Loop
Primary System
Drain Valve
Installation & Servicing Instructions
Electromax Housing
Primary System
Unvented System
11