6
Drain Point
A drain point should be fitted at the lowest point of the system. It is not acceptable to drain the boiler through the
safety valve as debris and deposits will prevent correct operation of the valve.
Heating System By-pass
The heating water flow switch requires a minimum flow rate through the boiler of 7 L per minute for correct
operation. Systems fitted throughout with Thermostatic Radiator Valves will require provision of a System By-pass
to maintain sufficient flow should all the valves be closed. (see 7.3 HEATING SYSTEM FLOW SWITCH – E3
ERROR).
System Expansion
An integral 6 L expansion vessel provides for expansion of the heated system water under normal conditions
however a system with larger volumes of water may require extra expansion capacity to be provided.
Cold Water Inlet
A ½” connection is provided for connection to 15mm pipe. An internal non-return valve prevents possible back-
flow should the water main fail.
CAUTION: If the incoming water pressure exceeds 5 bar it is necessary to install a Pressure Reducing
Valve set at 2.5 bar on the water main into the dwelling. This will protect the boiler and prevent constant opening
of the 7 bar relief valve.
Hot Water Outlet
A ½“ connection is provided for connection to 15mm pipe. To ensure economic operation the pipe run between
the boiler and taps should be in not more than15 mm dia. pipe and the distance as short as possible. The pipe-
work should be insulated to reduce heat loss.
4.8 SAFETY VALVE CONNECTIONS
The 7 bar pressure relief valve on the domestic hot water store may discharge boiling water and should be piped
to a safe but visible drain point e.g. a gulley where any discharge will not cause damage or injury.
CAUTION: A tundish should be incorporated close to the appliance where any discharge will be visible
but not hazardous. The pipe-work should have a continuous fall to the drain and should be of minimum 22mm dia.
if more than one discharge is connected to it.
The 3 bar pressure relief valve may discharge boiling water and should be piped with a continuous fall to a safe yet
visible point where any discharge cannot cause damage or injury.
CAUTION: The discharge pipe-work from the T&P relief valve must be installed by a competent person.
•
The discharge pipe material must be capable of conveying water / steam at 100ºC.
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All installations must be fitted in accordance with all local regulations in force at that time. Failure to
comply with these regulations will invalidate the manufacturers’ warranty.
4.9 PUMP DUTY
Boiler equipped with a high efficiency circulation pump, with a maximum impulsion height of 6.2 m and a maximum
flow of 3.3 m³ / h.
There are selectable operation modes with the built-in knob. You can select constant operating speeds I, II and III.
A LED indicator informs about the operating status of the pump:
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Green: correct operation.
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Green / red flashing: Lower voltage U<180V; overvoltage U>253V; Module overheating
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Red flashing: pump blocked.
