Thermalec Products
– 24THR Instruction Manual (rev 2)
Page 5 of 5
Colour
Meaning
Action
1
RED
Mains supply OK
Check main supply MCB or RCD has not tripped.
Check control fuse (inside unit), spare is provided.
2
AMBER
Pump Interlock
supply OK
Check that filter pump running (may be controlled by timer)
Check that 230V is present across terminals A and B.
3
RED
Heater supplies OK
Check that unit circuit breaker is switched on.
4
WHITE
Temperature safe
Reset Safety Thermostat by pressing red button.
If Thermostat trips again, check for insufficient water flow
caused by blockages or air in the system.
5
AMBER
Pump Interlock
relay OK
Check that pump interlock relay (inside unit) is securely
plugged in and switching
6
GREEN
Heating in progress
Check that Control Thermostat is set to desired pool
temperature.
Controller Drift.
The calibration of the controller drifts over time, requiring the value set on the dial to be
gradually increased to maintain the same actual temperature in the water. Thermostat should be replaced.
Contactors Frequently Switching.
Switching of the contactors every few minutes indicates that the direction
of water flow is incorrect.
Heater Circuit Breaker Trips.
Check if red reset button from Safety Thermostat has popped out. If so reset
and wait, if thermostat trips again check for sufficient water flow and air in system. If trip is not associated with
this check individual heating elements for insulation resistance.
Protective Devices on Supply Trip.
If RCD has tripped, first check that other equipment in the installation
has not caused the trip, then check heating elements for insulation resistance. If MCB has tripped, check it is
correctly rated (section 2).
Noise.
Exces
sive “buzzing” when heating indicates small amounts of rust on the pole faces of the contactor.
As mentioned in section 4, WD40 should be applied to the affected area.
Pool Not Reaching Desired Temperature.
If the status lamps are lit as described above and the contactors
can be heard engaging, then the heater can be said to be operating correctly. If the pool does not reach the
required temperature after an appropriate number of hours then the current drawn by the heater should be
checked using a clip-on ammeter. An alternative method is to set the temperature control several degrees
above normal and use the main supply meter to check how many Units (kWh) the heater consumes in an hour.
This figure should be slightly above the kW rating of the heater, allowing for the filter pump and other domestic
equipment on the same supply. If the consumption is less than the rating of the heater then the issue is
elsewhere in the system, for example:
Low voltage supplied to the heater, indicating that cable diameter is too small or run is too long.
Inadequate mixing of the warm water from the heater with the cooler water in the pool, leading to a layer of
warmer water forming at the height of the inlets. To cure, alter the direction of the pool inlet jet downwards.
Incorrect setting of any timeswitches fitted to heater or filter pump.
Timeswitches are not synchronised with the main electrical supply meter
Lack of water flow caused by insufficient pump head, or blockages in the pipe-work.
Warranty.
The heater is guaranteed for two years against faulty workmanship or materials. This does not
cover damage caused by incorrect commissioning & maintenance or by other neglect of the heater.
