Johnson & Starley WARMCAIR C20DW User guide

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INSTALLATION, COMMISSIONING
& SERVICING INSTRUCTIONS
WARMCAIR C20DW
Condensing Air & Water Heater
High Efciency Downow
Condensing Air & Water Heater
WarmCair C20DW - G.C. No. 43-417-61
These instructions are to be left with the User
Publication No. ZZ 1448-4
December 2016

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CONTENTS
The Benchmark Scheme 2
1 Features 3
2 General Description 3
3 Building Standards & Regulations 4
4 Safety, Electrical & Gas Information 4
General Safety Information
Power Flushing
Electrical Connections
Handling the unit
Operating the Appliance
Gas Supply
Water Supply
5 Technical Data 6
Technical Data
Performance Data
6 Heater Positioning 7
7 Heater Compartment Clearances 7
8 Duct System 7
Return Air
9 Heating System 8
Warm Delivered Air System
Additional Radiator System If Fitted
Schematics
Pipework Sizing
Water Treatment
Hot Water System For DHW
10 Flue Instructions 10
Types of Flue Systems
Flue Terminal Positions
Flue Requirements & General Information
Extended Horizontal Flue Configuration Examples
Vertical Flue Configuration Example
Optional Roof Outlets
Plume Terminal Outlets
Conventional 60/100mm Flue Accessories Part No.s
11 Condensate Pump & Drain Tube 15
Condensate Pump
Condensate Tube Routing Options
12 Electrical 16
13 Warm Air Fan Performance 16
14 Operating Modes 16
15 Domestic Hot Water Heating Commissioning 17
Check Gas Installation
Check the Operational Gas Inlet Pressure
Air Purge Function
Reset Procedure
16 Initial Lighting 18
Warm Air Central Heating
Water Circulation System
Balance the System
Central Heating Water Temperatures
17 Warm Air Heating Commissioning 19
With Thermista-stat Fitted
With No Thermista-stat Fitted
18 Handing Over 19
19 Servicing & Maintenance 20
Service Schedule
Initial Inspection
Servicing Sequence
Flue Inspection & Checks
Gaining Access to the Appliance
Air Filter Removal
Upper Panel Removal
Control Panel
Combustion Air Fan
Burner Assembly
Water Heat Exchanger
Servicing the Warm Air Heating
Gaining Access for Servicing the Heat Generator
Lower Panel Removal
Air Circulation Fan
Air to Water Heat Exchanger
Condensate Pump
Condensate Trap
20 Parts Replacements 24
Part Replacements without Draining the System
Control Panel
Burner Injector
Combustion Air Fan
Burner Assembly
Flow & Return Thermistor Sensors
Ignition/Detection Electrode
Gas Valve
Warm Air PCB
PCB Interface
Air Circulation Fan
Condensate Pump
Condensate Trap
Diverter Acuator Head
Parts Replacement By Draining the System
Draining the Appliance
Pump Head
Diverter Cartridge
Automatic Air Vent
Air To Water Heat Exchanger
21 Fault Finding 28
22 Wiring Diagram 34
23 Dimensions 35
24 Exploded Spares Diagram 36
25 List of Spares 38
26 List of Ancillaries 39
27 Benchmark Checklist and Service Record 41
Code of Practice
Commissioning Checklist
Service Record
In the interest of continuous development Johnson and Starley reserve the right to change specication without prior notice.
Johnson and Starley prides itself on it’s ability to supply spare parts quickly and efciently.
PLEASE READ THESE INSTRUCTIONS CAREFULLY BEFORE STARTING INSTALLATION.
LEAVE THESE INSTRUCTION WITH THE USER OR AT THE GAS METER AFTER INSTALLATION
The Benchmark Scheme
Benchmark places responsibilities on both manufacturers and installers. The purpose is to ensure that
customers are provided with the correct equipment for their needs, that it is installed, commissioned and
serviced in accordance with the manufacturer’s instructions by competent persons and that it meets the
requirements of the appropriate Building Regulations. The Benchmark Checklist can be used to demonstrate
compliance with Building Regulations and should be provided to the customer for future reference.
Visit www.centralheating.co.uk for more information.
Installers are required to carry out installation, commissioning and servicing work in accordance with the Benchmark Code of Practice which is available
from the Heating and Hot water Industry Council who manage and promote the Scheme.

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Sales/Spares & Replacement Help Line 01604 762881
1. FEATURES
Appliance Classification:
The WarmCair C20DW has been tested
and CE certified by B.S.I Ltd for use with
NATURAL gas G20.
FEATURES
1. Flue Adapter (shown fitted but not supplied)
2. Flue Test Point
3. Inspection Glass
4. Ignition Detection Electrode
5. Burner Injector
6. Flow & Return Sensors
7. Pressure Differential Tube
8. Gas Valve
9. Air Filter
10. Condensate Trap
11. Gas Cock
12. Circulation Fan
13. Pump/Diverter Assembly
14. Return Water Temperature Sensor
15. Heat Exchanger
(Warm Air)
16. Drain Cock
17. Access Panel
18. Condensate Pump
19. Condensate Pipe
20. Condensate Drain Tube
21. Electronic Air Filter & LED
22 PCB Interface
23. Combustion Fan
24. Warm Air PCB
25. Heat Generator
(water)
26. Flue Sensor
2. BRIEF DESCRIPTION
2.1 The WarmCair C20DW is a highly efficient combined condensing gas fired water to air downflow forced
convection air heater and water heater. Significant reductions in Carbon and NOx emissions are achieved.
This appliance has been designed with two compartments, one to provide the user with Warm Air Central
Heating and one to provide Domestic Hot Water. Using sophisticated controls and enabling it to provide a warm
air heat output of 16.0kW and hot water output of 24.2 fully modulating down to 4.8kW. It is room sealed, with a
stainless steel heat exchanger, using a vertical or horizontal Concentric Flue System.
The WarmCair C20DW combinds air heater is ideally suited for new built dwellings and the replacement of
existing non-condensing air heaters. For Indirect system applications only.
2.2 “Summer Air Circulation” of unheated air is available by manual selection (see the user’s instructions)
2.3 The air is drawn in through the air filter or air cleaner (if fitted) and the heat exchanger by a centrifugal fan, and is
discharged through the base of the unit. A Summer Air Circulation switch (optional) provides the facility to supply unheated
air to the air outlets during warm weather. Modairflow control is incorporated for modulating of the air circulation fan.
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FIGURE 1. CONTROL PANEL

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3. BUILDING STANDARDS & REGULATIONS
STATUTE LAW DEFINES THAT ALL GAS APPLIANCES MUST BE INSTALLED BY
COMPETENT PERSONS, i.e. GAS SAFE REGISTERED INSTALLERS.
GAS SAFE MEMBERSHIP ENQUIRIES TEL: [phone] IN ACCORDANCE WITH
THE GAS SAFETY (INSTALLATION AND USE) REGULATIONS (CURRENT EDITION).
FAILURE TO COMPLY WITH THESE REGULATIONS MAY LEAD TO PROSECUTION.
3.1 INSTALLATION REGULATIONS
• Building Standards (Scotland) (Consolidation) Regulations
• Building Regulations Part L
• Gas Safety (Installation and Use) Regulations (as amended)
• The Water Fittings Regulations or Water bylaws in Scotland
• Model and Local Authority Byelaws
• Health & Safety Document No. 635.
• The Electricity at Work Regulations, 1989.
• Institute of Electrical Engineers (I.E.E) Wiring Regulations
• EU Regulation No 811/2013 and No. 812/2013 supplement Directive 2013/20/EU
This appliance has been Tested and Certified in order to meet the necessary European Directives and
comply with the latest Building Regulations.
• Efciency of Hot Water Boilers Directive 92/42/EEC
• Gas Appliance Directive 2009/142/EC
• Low Voltage Directive 2006/95/EEC
• Electromagnetic Compatibility Directive 2004/108EC
3.2 BUILDING STANDARDS AND REGULATIONS
Where no specific instructions are given, reference should be made to the relevant British Standard Code of Practice.
BS 5440:1 Flues (for gas appliances of rated input not exceeding 70 kW).
BS 5440:2 Ventilation (for gas appliances of rated input not exceeding 70 kW).
BS EN 12828 Heating Systems in buildings: Design for water based heating systems.
BS EN 12831 Heating Systems in buildings: Method for calculation of the design heat load.
BS EN 14336
Heating Systems in buildings: Installation and commissioning of water based heating systems.
BS 5546 Installation of gas hot water supplies for domestic purposes (2nd Family Gases)
BS 6798 Installation of gas fired hot water boilers of rated input not exceeding 70 kW.
BS 6891 Installation of Low Pressure Gas Pipework of up to 28mm (R1) in domestic premises
(2nd family gases).
BS 7671 Institute of Electrical Engineers (I.E.E) Wiring Regulations
IMPORTANT: This appliance is CE certificated for safety and performance. It is important that no modifications are
made to this appliance, unless fully approved in writing by Johnson & Starley Ltd. If in doubt please Ring Johnson &
Starley Ltd on Telephone [phone].
4. SAFETY, ELECTRICAL, GAS & WATER INFORMATION
PLEASE READ THESE INSTRUCTIONS CAREFULLY BEFORE COMMENCING WITH THE INSTALLATION
4.1 GENERAL SAFETY INFORMATION
4.1.1 Only use WarmCair original spare parts on this appliance. Failure to do so will invalidate the guarantee.
4.1.2 The manufacturers instructions supplied must not be taken as overriding any statutory requirements.
4.1.3 No artificially softened water must not be used to fill the central heating system.
4.2 POWER FLUSHING - When a radiator system is also connected.
4.2.1 The system can be damaged by debris entering the heat exchanger and reduce efficiency. It is
recommended that the appliance is flushed, follow these guidelines as this will protect the unit and prolong
its life.
4.2.2
It is important that the system is flushed thoroughly before the appliance is left to operate (as recommended
in BS 7593) in order to maintain an efficiently operating heating system. For replacement installations, the
system MUST be flushed with the old unit in situ, in order to prevent the appliance becoming a trap for
system debris. Once the system has been flushed, an inhibitor (suitable for stainless steel heat exchangers)
should be added. Appropriate inhibitors are available, for example Sentinel, Fernox and Salamader. We also
recommend a Magnetic & Non Magnetic Filtration system is fitted between the last radiator and the boiler.
4.2.2 Failure to carry out the above procedure will invalidate the guarantee!

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Sales/Spares & Replacement Help Line 01604 762881
4.3 ELECTRICAL INFORMATION
4.3.1 Ensure the mains supply voltage, frequency, number of phases and power rating comply with details on the
rating label.
4.3.2 All wiring must be in accordance with the appropriate standards. The equipment must be supplied with a
double pole isolator switch.
4.4 HANDLING THE UNIT
4.4.1 Ensure safety regulations and practices are adhered to when installing and using this equipment
4.4.2 The weight of this appliance exceeds that recommended for a one-man lift. It will therefore be necessary to
gain assistance at times during the installation procedure.
4.4.3 It should be noted that this appliance may contain sharp edges. Care MUST be taken when handling the
appliance to prevent injury.
4.4.4 Once the appliance has been fired beware that certain parts will be hot to the touch.
4.4.5 Do not install flues during rain, high winds or in severe weather conditions.
4.5 GAS SUPPLY
4.5.1 It is the responsibility of the Gas Installer to size the gas installation pipework in accordance with BS 6891.
Whilst the principle of the 1:1 gas valve ensures the WarmCair Combined DHW range is able to deliver
it’s full output at inlet pressures as low as 14mb, other gas appliances in the property may not be as toler-
ant. When operating pressures are found to be below the minimum meter outlet of 19mb these should be
checked to ensure this is adequate for correct and safe operation.
4.5.2 Allowing for the acceptable pressure loss of 1mb across the installation pipework, it can be assumed that
a minimum permitted operating pressure of 18mb will be delivered to the inlet of the appliance. (Reference
BS 6400-1 Clause 6.2 Pressure Absorption).
4.5.3 The external gas cock could further reduce the operating pressure when measured at its test point. The
pressure drop is relative to the heat input to the boiler (kW), refer to graph below.
IMPORTANT: Installation pipes must be fitted in accordance with BS 6891. In IE refer to IS.813.
4.6 WATER SUPPLY
4.6.1 Water connections to the unit should be by 22mm compression fittings that are suitable for the duty.
NOTE: UNDER NO CIRCUMSTANCES SHOULD ISOLATION VALVES BE FITTED.
IMPORTANT: It is recommended that the water system be drained and flushed prior to the installation of the
unit. A strainer should be fitted upstream of the unit. See Paragraph 4.2.
FIGURE 2. GAS COCK PRESSURE DROP
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2
1.5
1
0.5
0
PRESSURE DROP (mbar)
0.0 0.5 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0
HEAT INPUT TO BOILER (kW)
GAS LEAKS
DO NOT OPERATE ANY ELECTRICAL SWITCHES, OR USE A NAKED FLAME
TURN OFF THE GAS SUPPLY. VENTILATE THE AREA BY OPENING DOORS AND
WINDOWS. CALL THE NATIONAL GAS EMERGENCY SERVICE ON
0800 111999