Technical documentation Technical documentation EOLO Star Instantaneous wall-hung room sealed fan assisted boiler with compact dimensions EOLO Star - GENERAL FEATURES EOLO Star is a wall-hung boiler with sealed chamber and forced draught for central heating and the production of domestic hot water. The boiler.
Technical documentation Technical documentation HYDRAULIC CIRCUIT 1 - Hot water NTC probe 2 - Hot water flow switch 3 - Gas valve 4 - Flow limiting device 5 - System draining cock 6 - Burner 7 - Rapid bithermal exchanger 8 - Gases expulsion fan 9 - Sealed chamber 10 - Venturi...
Page 6
Technical documentation Technical documentation - CIRCULATOR This operates on the primary circuit return and is located on the brass header assembly. It is connected to the enbloc and exchanger by means of threaded connecting pieces. The body features a threaded connecting piece to which is fastened the automatic outlet valve (1).
Page 7
Technical documentation Technical documentation - SAFETY DEVICES AND CONTROLS Automatic system by-pass (4) This ensures circulation in the central heating circuit even when this is prevented by the high resistance of the system. It operates between the supply and return of the heating circuit and is accessible after unscrewing the brass cap (5) on the side of the header (1).
Page 8
Technical documentation Technical documentation HYDRAULIC CIRCUIT HOT WATER CIRCUIT - OPERATION Running the hot water results in transit of cold water inside the flow switch (3) and consequent closing of the electrical contact coupled to this (see electrical circuit). As a result, the regulation circuit begins an operating stage with hot-water priority that starts the burner and, if a central heating request is under way, switches off the boiler pump.
Page 9
Technical documentation Technical documentation The closing of the contact, which is positioned outside the duct through which the water flows, enables the regulation board to start the hot-water priority operating mode. This consists of two blocks (one made of brass and one in plastic) which are joined by a clutch and secured by a pin (3).
Technical documentation Technical documentation GAS CIRCUIT The circuit consists of an atmospheric burner and a modulating type valve for gas combustion and gas flow adjustment respectively. - OPERATION When the main coils (3) are supplied, both inner valve shutters open, allowing the gas to flow towards the burner.
Technical documentation Technical documentation GAS ADJUSTMENTS Max and minimum gas pressure adjustments can be made by means of the gas valve respecting the values shown on the tables relating to each boiler for the type of corresponding gas. The features of this appliance are such as to make it possible to differ minimum pressure adjustments during operation in heating and hot water phases.
Page 12
Technical documentation Technical documentation FLUE GAS CIRCUIT - OPERATION The products of combustion, after investing the water-gas exchanger (1), are conveyed to a hood (2) on top of which the gas extractor (3) is fitted. Fan operation ensures forced expulsion of the gases and, at the same time, creates a vacuum in the sealed chamber (6) so the combustion air can be aspirated from outside.
Technical documentation Technical documentation - FLUE PRESSURE SWITCH (5) This is positioned in the upper internal part of the sealed chamber and, by means of the special points, detects the difference in pressure between the outlet of a special venturi pipe fitted in the fan exhaust (negative signal) and the inside of the sealed chamber itself (positive signal).
Page 14
Technical documentation Technical documentation EXTRACTION AND EXHAUST SYSTEMS (see extraction and exhaust end instructions ) EOLO Star is set for connecting to the special intake/exhaust coupling pipes. - EXHAUST Connection to the exhaust ducts is done by means of a flange (1) or a curved flange to be fitted to the connector (4) on the top part of the sealed chamber, placing in between a special shaped seal (6).
Page 15
Technical documentation Technical documentation Coupling type vertical concentric kit 60 /100 The exhaust pipe (φ 60 mm) is fitted inside the extraction pipe (φ 100 mm). Connection to the boiler is made using a flange (1) that, by means of the necessary extensions, must be connected to the special 60/100 extraction and exhaust end with aluminium tile.
Technical documentation Technical documentation LOADS This is powered by the adjustment board whenever there is a demand for heating or Circulator antifreeze. (MP) Permits circulation of water in the heating circuit. Ignition electrode This is controlled by the ignition circuit of the adjustment board which provokes an electric spark between its end and the burner surface that ignites the air/gas mix.
Page 18
Technical documentation Technical documentation Operates on adjustment board, enabling operation of the boiler during heating at selected times. Programmer clock switch If this is mounted singly, connection is made on terminals 6 and 9 of Double-contact (OP) connector M3 after removing pre-existing jumper P1. switch (optional) When fitted together with an ambient thermostat (TA) it must be...
Page 19
Technical documentation Technical documentation ELECTRICAL CIRCUIT HEATING PHASE When the main switch (IG) is in WINTER position, it powers the low-voltage circuit and enables board operation during heating. If the water pressure switch (SP) reads a pressure in the heating circuit above minimum value (SP switch closed), on closing the room thermostat contact (TA), the adjustment circuit starts circulator (MP) and powers the RELAY PUMP.
Page 20
Technical documentation Technical documentation ELECTRICAL CIRCUIT HOT WATER PHASE Operation When the main switch (IG) is in SUMMER or WINTER position, this powers the low-voltage circuit and enables operation in hot water phase. When the hot water is run, the microswitch contact (SS) of the hot water flow switch closes. This way, if the water pressure switch (SP) measures a pressure above minimum value in the heating circuit (SP switch closed), operation in hot water phase is enabled, during which the circulator (MP) is not started or is switched off in the event of heating request under way.
Page 21
Technical documentation Technical documentation MODULATION BOARD Inside the EOLO STAR control box is a microprocessor controlled electronic board that integrates ignition and adjustment functions and, by means of LEDs, shows the operating condition of the appliance, indicating any tripping of safety devices. - OPERATION Heating request When the main switch (IG) is in WINTER position and the system water pressure switch (SP) is closed,...
Page 22
Technical documentation Technical documentation Domestic hot water request With the main switch (IG) in SUMMER or WINTER position, when the hot water microswitch (SS) is closed, operation is enabled in hot water phase during which the circulator (MP) is not started or is switched off in the event of heating type request under way.
Page 23
Technical documentation Technical documentation INPUTS Enables the ignition circuit of the board to detect the presence of a flame on the burner. If this does not operate, the no ignition lock trips, signalled by the lighting up of LED LD2 Detection electrode (red).
Technical documentation Technical documentation OUTPUTS This is a positive square-wave signal with variable ON-OFF ratio (duty-cycle) that controls Modulation coil the modulation coil of the gas valve and makes it possible to alter gas pressure to the (MOD) burner. Ignition electrode This is a high voltage signal (about 16 kV) for energising the ignition electrode on the (E1) boiler.
Technical documentation Technical documentation SAFETY DEVICES With the master switch (IG) in SUMMER or WINTER position, the circulator (MP) is Circulator antilock operated for 30 seconds after 24 hours of inactivity. To restrict the formation of mineral deposits (limestone) in the event of leaks in the hot water circuit (taps not closed, hot water circuit leaks, etc.), the temperature of the boiler is restricted to 57 ºC if the NTC hot water probe (NS) detects a temperature increase during Hot water anti-leak...
Page 26
Technical documentation Technical documentation INDICATORS (yellow led) (red led) Depending on their condition, these indicate: - boiler off (no power) flashing - boiler in stand-by ON = 0.05 s (request standby) OFF = 3 s flashing - NTC hot water sensor breakage (NS) or heating (NM) ON = 1.5 s OFF = 1.5 s - burner operating...
Page 27
Technical documentation Technical documentation EOLO Star operation sequence Heating phase Hot water phase STARTING STARTING Main switch in WINTER position Main switch in SUMMER or WINTER position ⇓ ⇓ POWER TO ADJUSTMENT CIRCUIT POWER TO ADJUSTMENT CIRCUIT The closing of main switch contact (WINTER position) The closing of main switch contact (SUMMER position) powers the adjustment circuit and enables operation in powers the modulation board and enables operation in hot...
Page 28
Technical documentation Technical documentation EOLO Star TECHNICAL DATA Nominal heating capacity kW (kcal/h) 25.7 (22124) Minimum heating capacity kW (kcal/h) 11.2 (9674) Nominal heat output (useful) kW (kcal/h) 23.3 (20000) Minimum heat output (useful) kW (kcal/h) 9.3 (8000) Working thermal performance at rated power 90.4 Working thermal performance at 30% load of rated power 88.5...
Technical documentation Technical documentation COMBUSTION PARAMETERS (with combustion air temperature 15 ºC ) Rated power fume mass flow kg/h Minimum power fume mass flow kg/h at rated power at minimum power CO at 0% of O at rated power CO at 0% of O at minimum power at 0% of O at rated power...