The System - Potterton Envoy System 30 Installation & Service Instructions Manual

Installation Requirements - Page 8
Flow Return
(22mm) (22mm)
Boiler
Fig.4

The System

The Envoy System boiler has an aluminium alloy heat
exchanger, therefore all systems must be thoroughly
cleansed and the correct treatment added to the system
water.
The only system additives recommended by Potterton
Myson Ltd. are FERNOX-COPAL or GRACE
DEARBORN - SENTINEL X 100 and should be used in
accordance with the manufacturers instructions. This will
include use of the appropriate system cleanser.
The boiler must only be used on INDIRECT FULLY
PUMPED SEALED Systems.
To ensure sufficient pump head is available on the 80
model to overcome system resistance, a system
differential of 14°C should be allowed for when sizing
radiators.
Where the the D.H.W & C.H circuits are controlled by
two 2 port zone valves as illustrated or where all
radiators may be controlled by thermostatic radiator
valves a by-pass must be fitted.
Supplied By www.heating spares.co Tel. 0161 620 6677
Optional
3 Port
Valve
Alternative By-pass
Arrangement Using
By-pass
Radiator Fitted With
Balancing
Two Lockshield Valves
Valve
Filling
Point
Vent
Optional
Zone
Valves
The Bathroom
Fully Pumped
Sealed System
Drain off taps should be fitted in the pipework close to
the boiler and at all low points of the system.
Note: Although the system can be emptied using the
drain off taps installed in the pipework around the
system, to empty the heat exchanger it is necessary to
remove the drain off cap positioned within the boiler
case.
Installation
The installation must comply with the requirements of
BS 6798: 1987 and BS 5449: Pt 1.
The British Gas publication "British Gas Specification for
Domestic Wet Central Heating Systems" should also be
consulted.
The following components are incorporated within the
appliance.
a) Circulating pump.
b) Diverter valve (Optional Extra).
c) Pressure Relief valve with a non-adjustable pre-set
Cylinder
Make Up
Vessel