3
D420 Service Manual
Table of Contents
1 Introduction 5
1.1 Using this Manual 5
1.2 Understanding Fault Codes 6
1.3 The Control Panel 6
1.4 Setup Mode 7
1.5 Machine Supplied User Settings 7
2 Engineer Configurable Settings 8
2.1 Making Changes 8
2.2 Putting the D420 into Engineer Setup mode 8
2.3 The Engineer Menu Structure 9
2.4 Machine Supplied Settings 9
3 Obtaining Replacement Parts 10
3.1 Illustrated Parts Catalogue 10
3.2 Using Web Site 10
3.3 Obtaining User name and Password 10
3.4 Locating Part Illustration, Description and Number 10
3.5 On-line Parts Enquiry Form 10
3.6 Exploded View Assembly Drawing 10
4 Preparing the D420 for Servicing 11
4.1 Preparing a Suitable Work Area 11
4.2 Noting Machine Settings 11
4.3 Removing the Casing Panels 12
4.4 Refitting the Casing Panels 12
4.5 Disconnecting / Reconnecting Power Supply 13
4.6 Disconnecting / Reconnecting Water Supply 14
4.7 Draining the Tank 14
4.8 Draining Water Inlet Hose Pipe 15
5 Servicing Tank and Water Supply 16
5.1 Replacing the Water Inlet valve 16
5.2 Replacing Water Outlet Valves 16
5.3 Setting Water Outlet Valve Flow Rate 17
5.4 Replacing Heating Elements 19
5.5 Replacing Boiler Temperature Control Thermister 21
5.6 Calibrating the Thermister 21
5.7 Replacing Boiler Over Temperature Thermostat 23
5.8 Replacing a Float Microswitch 23
5.9 De-scaling the Tank 24
5.10 Cleaning Water Outlet Valves 25
