Hunter Herald 14 CE V.II Installation And Operating Instructions Manual page 8

INSTALLATION OF BOILER MODELS
We strongly recommend that a knowledgeable, experienced and qualified plumbing and heating
engineer is responsible for the design and installation of the heating and hot water system. Hunter
Stoves Ltd cannot accept responsibility for any consequential loss, however caused, due to under or
over specification of the appliance in any installation.
Do Not –
Under any circumstances connect the stove to a sealed (pressurised)
heating system or unvented hot water cylinder.
Do Not –
Link the stove into a heating or hot water system with an existing boiler without the
use of suitable equipment such as a neutralizer. When fitting this type of system the
neutralizer manufacturers instructions must be followed.
Do –
Fit an open cold feed and expansion cistern with separate cold feed and vent pipes.
The cold feed and vent pipes must be unvalved. The open vent pipe should have a
diameter of 22mm and rise continuously from the boiler. It is common practice to
form the vent pipe from an extension of the primary flow (see diagram).
Do –
Connect the stove to a double feed, indirect hot water cylinder via 28mm copper
flow and return pipework, rising continuously from the boiler to the cylinder. The
cylinder and heat leak radiator must be sited higher than the stove.
Semi pumped systems should be used on heating and hot water systems with gravity circulation to
the hot water cylinder and one unvalved 2 KW radiator to act as a heat leak when the central
heating is switched off.
All four tappings on wraparound boilers should be used for systems incorporating separate gravity
and pumped heating loops. Each flow and return should be taken from diagonally opposite sides of
the boiler.
If a common flow and return is used, these should also be taken from diagonally opposite sides of a
wraparound boiler, and plugs inserted into the sockets not used.
Systems using a common flow and return to the boiler should incorporate an injector tee on the
primary return connection from the central heating pump (see diagram).
A HIGH LIMIT thermostat should be fitted to the gravity flow pipe close to the boiler and set at
90°C. This should override any pump control, switching the pump on and dissipating any excess
heat around the radiator circuit.
To prevent boiler corrosion due to condensation it is necessary to maintain the return water
temperature above 45°C. This can be achieved by the use of a LOW LIMIT thermostat on the return
pipe from the hot water cylinder, close to the boiler. The thermostat should make on temperature
rise, preventing the circulating pump from operating until the gravity circuit is up to temperature.