The Return pipe to the heat exchanger from the existing pressurised system should be
connected directly to the main/principal return pipe of the existing pressurised circuit.
The flow/return from/to the heat exchanger must be pumped.
BestpractiseistotathermostattoyourDHWcylinder,whichwilldiverttheheattothe
heating system when your DHW cylinder is satisfied. This will prevent the DHW tank from
over heating.
A pressure relief valve must be installed on the pressurised side of the unit. It cannot be
isolated from the pressurised circuit.
Bestpracticeistoconnectaheatleakradiatorfromtheverticalowandreturnpipework
of the stove as per schematic. It should be connected on the expansion pipe above the
level of the SFHE. The radiator should be 10% of the output of the stove. e.g. 12kW stove
should have a 1.2kW radiator. The heat leak radiator should have no valves, TRV, or any item
which would inhibit the flow to the radiator.
It is best practice to fit a bypass around the pump on the vented circuit. In the event of an
interruption to the power supply, the SFHE will circulate via gravity around the pump,
avoidingabuildupofpressure.AninjectorTmustbettedbetweenthepumpandthe
stove on the return side as per schematic. This will guide the water to the stove and prevent
it circulating around the bypass. If the pump is not operating, the non-return valve prevents
the flow of water through the pump and instead, takes the route around the bypass.
Only1”or28mmcopperpipemaybeusedtoconnecttheSFHEtothestove.Toensurethe
optimum transfer of heat, the SFHE should be located between 1.5m and 7m from the
stove (in one direction i.e. 14m in total). The open/vented system supply pipe must be at
least½”or15mmcopperpipe.
Plate Heat Exchanger
The SFHE includes a plate heat exchanger. This unit requires clean system water to operate
efficiently. The installer must ensure that the solid fuel and heat system circuits are clean.
BothsystemsshouldbepowerushedinaccordancewithBS7593.Aproprietaryinhibitor
should be added on commissioning. We recommend a permanent magnetic filtration filter
to be fitted on the return pipe work after the last radiator on the central heating system.
This will maintain maximum operational efficiency and protect the unit from damaging
longtermeectsof“blackironsludge”.Themagneticltershouldbeinstalledatalltimes
according to the manufacturing instructions.
TocomplywithBuildingRegulations,inparticularPartL,allsolidfuelheatingunits
must be linked directly to an open vented system and must have an open gravity
circuit.
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