Safety Devices - Heatline SARGON 18S Installation, Servicing And User Instructions Manual

15.5 The maximum and minimum heat output for heating : Hot water output is dictated by
demand whilst the heating is pre-set on potentiometer 29 at 4 o'clock (fi gure 22). The C/H
may be adjusted to match your heating requirement if required.
15.7 Gas valve ignition capacity : The graduated opening of the gas valve for ignition rate
is governed by the potentiometer R30 control, which is factory set at 6 o'clock.
15.8 The boilers integral pump is factory set to its maximum speed setting to give a 1000 l/hr
fl ow on a nominal 4m head. The pump may be adjusted to a lower speed to match
the designed central heating system requirements. (See Figure 24 for fl ow rates)

16. Safety Devices

16.1 An hydraulically operated primary pressure switch monitors water pressure or water
shortage in the primary hydraulic circuit and will switch the boiler off if the pressure is below
0.8bar. The boiler will not operate until the circuit has been re-pressurised.
The recommended pressure of the system is 1.5bar when cold.
16.2 The temperature of the water fl owing from the primary heat exchanger is monitored
by an overheat thermostat located on the outlet pipe. If the water temperature gets too hot
the switch opens, cutting off the electrical supply to the gas valve and causing the boiler
to 'Lock-out', fault code F1. Once activated the boiler has to be cooled and manually re-set
by switching the control knob off for a minimum of 30sec and on again. If the boiler fails
to re-set then the Thermal Fuse described in Section 18.3 must be checked and replaced
if necessary.
16.3 The boiler's control unit has an in-built frost protection device that fi res the boiler's
burner when the temperature of the primary hydraulic water falls below 6°C. The device
works irrespective of any room thermostat setting and will protect the boiler. Once the water
temperature reaches 16°C the boiler reverts back to normal operation. If there is a risk
of pipes freezing in exposed places these should be well lagged and the system drained and
power switched off if the property is left empty for long periods during cold weather.
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