Wiring Diagrams - gledhill Torrent GreenHeat OV TGH140 Design, Installation & Servicing Instructions

INSTALLATION
Gravity Flow Solid Fuel Boiler Pipe Layout
Feed and expansion tank sized to include
the expansion of solid fuel boiler, open vented
boiler and open vented central heating
Control
stat 2
Heat sink radiator
(ensure lockshields
are left fully open)
Solid
fuel
vent
Normally
closed
2 port valve
Normally open
Pipe
2 port valve
stat 1
This circuit usually uses gravity circulation.
Good circulation depends on the system
height and the temperature difference
between the hot flow and the cool return
to provide the motive force to overcome
the frictional resistance in pipe and
fittings and provide circulation.
Multi-fuel stove
Solid Fuel Option
All models of the Torrent GreenHeat shown in this installation manual have the tappings
included as standard for a solid fuel boiler. In the absence of recommendations from
HETAS or the solid fuel boiler manufacturer, we would advise the following pipe layout
to achieve the best performance from your solid fuel system and our thermal store.
This diagram represents a good example of a gravity circulation pipe layout. Points to
note are;
• All pipework rises towards the cylinder and the heat sink radiator and fall back
towards the solid fuel burner.
• The heat source is below the cylinder which gives the layout a good system height.
• All gravity circulation pipework is recommended to be 28mm or above pipe
diameter, at low ow speeds the pipe resistence is negligible in this pipe diameter.
• Avoid long horizontal runs and try to make the ratio horizontal:vertical to be a
maximum of 20:80.
To ensure that the solid fuel boiler does not overheat the thermal store during its
operation and prevent gravity circulation cooling the thermal store when it is not, the
following controls can be used. Other methods of control can be used; HETAS and/or
the solid fuel boiler manufacturers instructions should be consulted. This control system
is fed from a dedicated fuse spur to enable safe isolation for changing components. All
wiring should comply with BS7671 Requirements for Electrical Installations 17th edition.
Typical components (not supplied but available to purchase from Gledhill Spares Ltd);
• 1 x Honeywell V4043B1265 - 28mm compression normally open 2 port valve
• 1 x Honeywell V4043H1106 - 28mm compression normally closed 2 port valve
• 1 x Honeywell L641B1012 - High limit pipe thermostat
• 1 x XC010 control thermostat
When the boiler is lit, the water temperature raises. When the temperature is above
SOLID FUEL BOILERS
pipe thermostat 1 set point, the contacts
close signalling the normally closed valve to
move open. Once it is fully open, it signals the
normally open valve to motor there by closing
it. The thermal store now receives heat from the
Min. 250mm solid fuel boiler via gravity circulation.
If control stat 2 set point is exceeded then
the power to the normally closed valve is cut
which in turn cuts the power to the normally
open valve. Excess heat from the solid fuel
boiler is then circulated around the heat sink
radiator. Careful selection of the pipe thermostat
switching temperatures should be made during
commissioning to get the best performance from
the system. 85°C is the maximum temperature
that the control stat 2 should operate at.
There are 2 solid fuel returns on the Sol
cylinder range to enable the whole store water
volume to be used to store heat when the solar
contribution is negligible. For example, a solid
fuel boiler that is used for space heating would
only be used in the winter months when the
solar contribution is small. Connecting it to
lower return enables the store to hold more
heat when the sun cannot provide as much.
Alternatively an Aga which runs 24 hours 365 days
a year would need to be connected to the upper
return when the solar contribution is greatest and
the lower when the solar contribution is least. A
pair of simple isolation valves may be used to
switch from summer to winter mode or more
sophisticated control methods used.
To ensure e ective operation of the thermal
store it must not be overheated. The overheat
thermostat should be set at a temperature
which operates before or at 85°C. Please see
page 23 for further information .
Feed and Expansion Tank
A feed and expansion cistern supplying a system
heated by wet solid fuel appliance should either
be of metal construction (copper, stainless
steel etc.) of manufactured of a material
that has been certi ed as being suitable for
temperatures up to 110°C. These are available
to order from Gledhill at the time of purchase.
The capacity of the cistern should be at least
one twentieth of the total system volume.
The cistern should be tted with a brass oat
operated valve that is manufactured to BS1212
Pt. 2 and is tted with an appropriately sized
copper oat. The over ow pipe should be either
made of metal or manufactured from a material
that has been certi ed as being suitable for
temperatures up to 110°C. The over ow pipe
must have appropriate support – for plastics
this may require continuous support.
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INSTALLATION

WIRING DIAGRAMS

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