HeatStar XF EC, Product Manual, Page: 30 / 55

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BOILER DEMAND SWITCH (Super Plus only)
This would apply to Heatstar
‘Super Plus’ versions only.
To completely switch off the boiler and/or circulation pump during periods when heating is not required, an
electrical switch is provided in the Heatstar, see electrical connections.
This is a 230v 3 Amp live electrical signal switch, which is an extension of the auxiliary contacts located within
the internal motorised valves. A zero volt contact switch is also provided within the unit as an alternative facility.
The switch signal is present when the Heatstar requires heat from the boiler to heat either air, pool water or both.
The signal is not present when no heat is required from the boiler.
It is recommended that boiler is dedicated solely to the Heatstar.
However, if other separate heating systems are fed from the same fuel boiler, i.e. radiators etc, then this switch
would have to be wired in parallel, via an electrical relay, with the contacts of any other motorised heating valves
linked to the same fuel boiler.
The boiler demand switch is a safety protection device and helps guard against excessive over-heating of the
pool water in the event of a fault condition. Therefore the switch should be connected and confirmed to be
operating correctly.
The use of the boiler demand switch will also contribute to energy efficiency by switching off the boiler
completely during period of no demand of heat.
The boiler supplying heat to the Heatstar should not be governed by any form of time clock control. The
Heatstar may call for heat from the boiler at any time, day or night, and, if that heat is not available, then control
of the pool room environment will be compromised.
The electrical supply to the boiler should be routed from the Heatstar, via an MCB and local isolator switch.
To aid future maintenance to the boiler system, it is advised that the boiler MCB & Local isolator are marked and
labelled to clearly indicate that the electrical supply is routed via the Heatstar and will only be present
intermittently.
WIRING THE BOILER WATER CIRCULATING PUMP
It is advised that the boiler water circulating pump is wired to only operate on demand of heat, in line with UK
building control regulations.
To prevent the possibility of the pump operating against a dead end, it should be confirmed that :
- A by-pass pipe / valve facility has been included within the boiler water pipe circuit to the Heatstar.
Or, that any external motorised heating valves are 3 way in type i.e. simply divert, as opposed to shut
off, the flow of water from the boiler.
WIRING AN EXTERNAL BY-PASS VALVE (Super Plus only)
If it is not practical to dedicate the function of the boiler and boiler pump to the Heatstar, it may be necessary to
install a motorised by-pass valve. This valve should remain closed when the Heatstar was demanding heat but
should automatically open when the Heatstar is no longer demanding heat and the motorised valves within the
Heatstar have closed.
A 230v electrical supply is available from the Heatstar for the purpose of powering open the by-pass valve when
heating is no longer required.