Biasi GARDA M90F.24S - User Manual

Wall hung, fan flue, room sealed gas boiler
SERVICE MANUAL
GARDA
Models: G.C. Appl. No.
M90F.24S 47--970--19
M90F.28S 47--970--20
M90F.32S 47--970--22
M90F.24SR 41--970--10
M90F.28SR 41--970--11
Leave this manual adjacent to the gas meter
Biasi UK Ltd
Newman Park, Western Way
Wednesbury, WS10 7BJ
Sales Tel No: 0121 506 1340
Sales Fax No: 0121 506 1360
Service Tel No: 0121 506 1350
Service Fax No: 0121 506 1370
www.biasi.co.uk

Summary

Fault Finding

Components to Check for Faults

Lists components for troubleshooting specific boiler faults.

Primary Heat Exchanger

Removal and Cleaning

Step-by-step instructions for removing and cleaning the primary heat exchanger.

D.H.W. Heat Exchanger

Pump

Three Way Diverter Valve

Removal of the Electric Actuator

Steps to remove the diverter valve's electric actuator.

Diverter Group and Internal Parts Removal

Removal of the Diverter Group

Detailed steps for removing the diverter valve assembly.

Electronic Starting Control PCB

Selection and Adjustment Devices

PCB Temperature Control

Checking the Temperature

PCB Dip-Switch Selectors

Dip-Switch Selector Functions

PCB Adjustments and Checks

Ignition Gas Pressure Adjustment

Procedure to adjust gas pressure for ignition.

Max C.H. Power Adjustment

Modulating Gas Valve

Adjustment

Procedures for adjusting gas pressure settings on the valve.

Gas Valve Checks and Removal

Removal of the Gas Valve

Step-by-step instructions for removing the entire gas valve.

Primary Circuit Flow Switch

Expansion Vessel and Temperature-Pressure Gauge

Removal of Expansion Vessel

Temperature-Pressure Gauge Removal

Removal of Temperature-Pressure Gauge

D.H.W. Flow Switch, Filter and Flow Limiter

Removal of Flow Switch Sensor

Flow Switch Group and Filter Removal

Removal of Flow Switch Group and Filter

Temperature Probe

By-Pass Valve

Ignition and Detection Electrodes

Function

Explains the role of ignition and detection electrodes in the burner sequence.

Safety Thermostat

Function

Describes the safety thermostat's role in preventing overheating.

Checks

Procedures for checking overheat temperature settings and electrical function.

Removal

Step-by-step instructions for removing the safety thermostat.

Biasi GARDA M90F.24S Specifications

General

Type	Combi
Mounting	Wall-mounted
Output Power	24 kW
Central Heating Output	24 kW
Domestic Hot Water Output	24 kW
Fuel Type	Natural Gas
Max working pressure	3 bar
Flow rate at ΔT 35°C	9.8 l/min
Dimensions (HxWxD)	700 x 400 x 290 mm