Manual 01 - Section 09

Residential Solar Information Manual
Section 9 - Optional Equipment and Accessories.


The Solahart Optimiser has been designed to meet typical hot water usage patterns and based on our forty years of field experience. The Optimiser is micro-processor controlled and provides a range of control features. A dedicated Liquid Crystal Display (L.C.D.) provides the user with information on the status of the solar hot water system whilst the control panel allows full interaction with the system

The Optimiser control unit can be connected directly to the FD15-12 Gas booster or to an electrical booster via an interface unit (TEK415). The electrical interface unit contains a transformer and electronic components to power the Optimiser control panel and to supply the controller with status information from the solar hot water system.

The interface unit also contains a heavy duty relay capable of switching 20 Amps (4.8 kW). This relay will switch the element on and off on as commanded by the Optimiser unit. The interface unit is fitted on the left hand side of the tank, and replaces the existing element access cover.


De-pressing the Off button will disable the selected booster control modes, and will blank the boost icons on the display. The Optimiser will still be communicating with the solar hot water system. Selecting one of the booster control mode buttons will return the Optimiser to full operation without the loss of previously established timer settings.


The vessel temperature is continuously monitored by the Optimiser and displayed as a bar graph to help the user decide if boosting is necessary. The user can also determine the water temperature most comfortable for their needs. The display is based on 6 bars giving 5 steps of 8ºC, this covers the approximate range of 40ºC to 80ºC. Please note that delivered hot water temperature may vary throughout the house due to heat loss in the pipe work.


The Thermostat Control dial on the Optimiser covers a vessel temperature range of approximately 55ºC to 65ºC.

The Optimiser provides to four different booster control modes:


The Continuous Boost mode allows the vessel-mounted thermostat to control the water temperature to that selected by the Thermostat Control on the Optimiser.


The Timer incorporates a time clock capable of two independent, user programmable, on/off operations per twenty-four (24) hours. At least one 'on' and one 'off' program must be selected by the user to enable operations of the timer mode.


Selecting Single Boost will enable a single, one shot boost if the water temperature is below that selected by the Thermostat Control on the Optimiser. The continuous icon will flash to indicate a single boost has been selected. The single boost will continue until the water has reached either a minimum of 60ºC or the Optimiser Thermostat Control set point. The Optimiser will then return to the previous control mode setting. The Single Boost can be used in combination with the Timer and the Optimum modes.


When the Optimum mode is selected the booster will be switched on and off according to a pre-programmed algorithm. The algorithm takes account of the time of the day, available solar energy at the collectors and the vessel water temperature. (A temperature sensor is fitted to the top collector union to determine the available solar energy.)

The following algorithm has been programmed into the unit for the Optimum mode setting:


 Between 18:00 and 00:00     Less than 40ºC              ON         
 Between 00:00 and 04:00     Less than 40ºC              ON         
      At 04:00               Less than 45ºC              ON         
      At 05:00               Less than 50ºC              ON         
      At 06:00               Less than 55ºC              ON         
 Between 06:00 and 10:00                                 NO BOOSTING    
      At 10:00               SOLAR SENSOR TEMP           ON         
                             Less than 40ºC                      
      Between                SOLAR SENSOR TEMP           ON         
  11:00 and 18:00            Less than the Time x 5

For example if at 13.00 hours the sensor temperature is 55ºC, the booster will be on. This is because the collector temperature is less than 13x5= 65ºC.

The algorithm is designed to ensure maximum energy savings for the average household with average usage patterns. The Single Boost feature is most useful when system is in Optimum mode and a short term, high volume hot water demand arises.




Optimiser Control Unit TEK 414     Operating Voltage +5V dc          
Booster Interface Unit TEK 415     Operating Voltage 216 to 264 V AC
                                   Contact Rating 20A                

                                   Operating Temperature Range 0-65ºC
Status LED inside TEK 415 unit to report 4 operating conditions                                                 

# 1 LED flashes every 3 seconds    Normal Operation Booster OFF

# 2 LED continuously on            Normal Operation Booster ON

# 3 LED flashes rapidly            Over temperature detected while boosting

# 4 LED flashes slowly             Lost communication with Optimiser control unit





This Heat Dump Kit has been designed for use on Solahart 302K units only.

A thermostatic valve, (DT100V) is fitted in the storage tank or heat exchanger tail end socket and connected to the cold water inlet socket via a 25.4 mm (1") diameter copper pipe running around the back of the vessel.

When the tail end socket (centre of the tank) reaches 65 to 73°C, water circulates (by thermosiphon) through the valve and pipe, dissipating about 10°C on its passage from the tail end socket back to the cold inlet socket. In this manner heat is only dissipated from the lower half of the container and the hot water outlet temperature remains at a useable level. The Heat Control Valve and Pipe may operate 24 hours a day if necessary or until the tail end socket temperature falls to below 65C.

Each kit contains a thermostatic valve (DT100V) and a Copper Heat Control Tube.

For locations with very high radiation levels, J Collectors should be considered to reduce excessive hot water temperatures.


A vandal resistant, steel mesh guard is available to protect the collector glass. The guard clips over the sides of each collector and is fitted after installation of the solar hot water system. The Stone Guard locks in place without the use of additional fixings.

The Stone Guard for the HotTop unit has four lugs attached to allow the guard to be screwed onto the casing.

Screen material................. Galvanised steel
mesh size....................... 50 x 50 x 4 mm
Collector aperture reduction.... 16 %


Cyclone frames are available for 1 and 2 collector systems. All the hardware required to assemble the frame and the parts to fit the solar unit to the frame are supplied in the Frame Kit. Hardware required to fit the frame to the roof must be supplied by the installer.

The Cyclone frame is press formed from 2 mm zinc plated steel sheet. Rivet nuts are fitted into the base plate for ease of assembly. Aluminium extrusions are supplied to support the collector(s) on the frame, the top aluminium extrusion captures the front tank foot and acts as a spacer between the tank and collector.

If the Cyclone Frame is to be installed on a tiled roof, the frame must be mounted clear of the roof surface by using 12 mm diameter threaded rods. (Refer to the installation leaflet for detailed drawings regarding the different fixing methods).

The Cyclone Frame has been approved for use in areas susceptible to cyclonic conditions with a wind velocity of up to 57 m/s.

(Australian Cyclone Terrain Category 2)


17.5° and 30° "A"-Frames are available. The A-Frames should not be used in cyclone or very high wind areas.

A-Frames are designed to enable a solar unit to be mounted on a flat roof or against the pitch on a sloping roof.

The frames are made of welded steel angle with a galvanised finish. The base plate and top had sections are pressed from 2 mm zinc plated steel. The A-Frame kits are supplied with heavy duty aluminium extrusions to support the collector(s) and 4 aluminium tank clamps.

Pipe legs are provided in the A-Frame kit for side pitch and against pitch installations.

These legs are to be cut to length on site.


In areas with very hard water conditions, build up of calcium on conventional immersion elements can cause premature failure due to over heating. The built up calcium layer insulates the element and prevents conduction of heat into the water.

A Bobbin Style Element can be fitted to overcome this problem. The heat output of this element is spread over a greater surface area reducing the rate of heat exchange. This minimises build up of calcium.

The Bobbin Element tube is protected with a vitreous enamel lining.

The Bobbin Element consists of a ceramic core wound with spiralled resistance wire and placed into the Bobbin Element tube. The ceramic element core can be replaced without the need for draining or de-pressurising the vessel.


The manual Solahart Booster Switch provides a double pole switch with 20 Amp rating and is capable of switching 4.8 kW elements.

The red indicator light has a supply rating of 250 V.

The red indicator light will be 'on' when the electrical supply to the booster thermostat is on. The Booster Switch assembly is used for installations where the user requires manual control of the booster from within the residence.


The HotTop Energy Saver Kit contains an energy saver relay, element gasket and a thermostat. The parts are supplied with a stepped metal cover to replace the existing cover plate.

The booster element is not supplied. Straight single hair pin elements with a maximum rating of 2.4 kW may be used..

The HotTop Energy Saver Kit is pre wired and the only wiring required on site is the electrical supply and the element wires.

The energy saver relay will ensure that only one boost is performed at a time. If another boost is required, the booster switch needs to be switched again to reset and start a new boost cycle.


The Commissioning Kit, (part number 105602) is designed for closed circuit systems with conetite fittings and contains all the components necessary to commission or service closed circuit systems. Individual parts can be ordered by their part number as shown below.

The Commissioning Kit for the O'Ring type fittings is available under part number 105601. Separate items can not be obtained from this kit.

The testing procedure for the closed circuit is described in Technical Bulletin 97 (December 1992)