Immergas EOLO 21 Maior User Manual

Technical documentation Technical documentation
STEM@ ed 06/01
1
EOLO MAIOR @
EOLO Maior @
Instantaneous wall-hung boilers
with sealed combustion chamber
fan assisted
EOLO 21 Maior @
EOLO 24 Maior @
EOLO 27 Maior @
- GENERAL FEATURES
The EOLO Maior @ series comprises sealed-chamber boilers with forced draught (fan assisted) for
central heating and the production of domestic hot water.
The range includes electronic-ignition versions with working outputs of 21,000 kcal/h (24.4 kW), 24,000
kcal/h (27.9 kW) and 27,000 kcal/h (31.4 kW).
Adjustment and control of the boiler are entrusted to a microprocessor-controlled electronic board
thanks to which the appliance can be connected to the Remote Friend Control (optional).
The hydraulic circuit features a copper water-gas exchanger, an automatic system by-pass and a new
brass monobloc to which is fitted the hydraulic 3-way valve which ensures, according to need,
circulation of boiler water in the heating system or in a stainless-steel plated exchanger for the
instantaneous production of d.h.w.
Combustion air flow into the sealed chamber and flue extraction are ensured by a fan, the correct
operation of which is controlled by a differential pressure switch.
All the models feature as standard an antifreeze safety device that protects down to temperatures
as low as -5°C.
- MAIN DIMENSIONS AND CONNECTIONS
DIMENSIONS (mm)
HEIGHT WIDTH
DEPTH
EOLO 21/24/27
850 450 350
CONNECTIONS
GAS
D.H.W.
SYSTEM
G U E R M
EOLO 21/24/27
1/2 “ 1/2 “ 1/2 “ 3/4 “ 3/4 “
V - power connection
G - gas supply
U – domestic hot water outlet
E – domestic hot water inlet
R - system return
M - system flow

Immergas EOLO 21 Maior Specifications

General

Brand	Immergas
Model	EOLO 21 Maior
Category	Boiler
Language	English

Summary

General Features of EOLO Maior Boilers

Main Dimensions and Connections

Main Component Parts Overview

Control Panel Functions

Hydraulic Circuitry

Primary Circuit Overview

Explains the primary circuit, its operation, and the circulator component.

Secondary Circuit (D.H.W.)

Details the secondary circuit for domestic hot water production and its exchanger.

Head Flow Graph Interpretation

Primary Heat Exchanger Details

Safety Devices and Controls

Key Safety Components

Details on automatic by-pass, filling unit, pressure switch, safety valve, air vent, and expansion vessel.

Hydraulic 3-Way Valve

Valve Idle Position (Central Heating)

Details the idle state of the 3-way valve for central heating operations.

Valve Operating Position (D.H.W.)

Describes the operating state of the 3-way valve for domestic hot water.

Gas Circuit Components

Modulating Gas Valve

Details the modulating gas valve, its coils, and settings.

Burner Assembly

Details the burner, ignition electrodes, and detection electrode.

Gas Adjustments

Valve VK 4105 M Adjustments

Minimum and maximum pressure adjustment for the VK 4105 M valve.

Valve VK 4105 M-M Adjustments

Maximum and minimum pressure adjustment for the VK 4105 M-M valve.

Changing Type of Gas

Extraction and Exhaust Systems

System Connections and Components

Describes exhaust/extraction connections, sampling, and flue pressure switch signals.

Installation Kits

Covers horizontal/vertical concentric and separator kits for exhaust/extraction.

Electrical Circuit

230 V AC Circuit and Safety Devices

Details the 230V AC circuit, including safety devices like electrodes and fuses.

230 V AC Loads

Lists the loads powered by the 230V AC circuit, such as the ignition unit.

Low-Voltage Circuit

Low-Voltage Safety Devices

Details safety devices and controls operating on the low-voltage circuit.

Low-Voltage Loads

Lists the loads powered by the low-voltage circuit, like the modulation coil.

Electrical Circuit - Central Heating Phase

Operation with Room Thermostat

How the boiler operates in central heating mode using a room thermostat.

Operation with Remote Friendly Control

How the boiler operates in central heating via remote control.

Electrical Circuit - D.H.W. Phase

Domestic Hot Water Operation

Explains the boiler's operation sequence for domestic hot water production.

Modulation Card and Operation

Heating and DHW Control

How the modulation card manages heating, DHW, and remote control requests.

Antifreeze and Special Requests

Details on antifreeze requests and specific operational modes managed by the card.

Input Signals and Sensors

Signal and Control Inputs

Details on gas valve supply, flame lock, control zone, remote control, and main switch inputs.

Sensor and Switch Inputs

Details on pressure switches, D.H.W. signals, sensors, and room thermostat inputs.

Outputs

Control Signals and Relays

Outputs related to modulation coil, zone control, remote control, pump, and request relays.

Adjustments

Temperature and Gas Settings

Settings for central heating, D.H.W. temperature, and gas type (natural gas/LPG).

Power and Timing Adjustments

Adjustments for D.H.W. modulation, central heating timing, max/min power, and soft ignition.

Safety Devices

Operational Safety Features

Circulator antilock, insufficient circulation, pump post-circulation, and NTC sensor fault protections.

Indicators

LED Status and Error Codes

Interpreting LED indicators (H1, H2, H3) and CAR error codes for diagnostics.

Operating Sequence

Heating Phase Sequence

Step-by-step process for central heating operation from power-on to burner ignition.

Domestic Hot Water Phase Sequence

Step-by-step process for domestic hot water operation from request to burner ignition.

Technical Data

Combustion Parameters

Heat Output Adjustments

EOLO 24 Maior Series Adjustments

Heat output adjustments for EOLO 24 Maior and 24 S @ models across gas types.

EOLO 27 Maior Series Adjustments

Heat output adjustments for EOLO 27 Maior @ model across gas types.