2000225000B.02.02 Instructions for Use Installation and Servicing 10139 To b e l e f t w i t h t h e u s e r 23c Fanned Flue Combination Boiler G.C. No. 47-047-18 This is a Cat I2H Appliance optional electro mechanical clock timer shown fitted The instructions consist of three parts, User, Installation and Servicing Instructions, which includes the Guarantee Registration Card.
Important Information Testing and Certification This boiler is tested and certificated for safety and performance. It is therefore important that no alteration is made to the boiler, without permission, in writing, from Hepworth Heating Ltd. Any alteration not approved by Hepworth Heating Ltd., could invalidate the certification, boiler warranty and may also infringe the current issue of the Statutory Requirements.
Contents CONTENTS INSTRUCTION FOR USE INSTALLATION INSTRUCTIONS SERVICING INSTRUCTIONS DESCRIPTION SECTION Important Information Introduction Controls and Lighting Clock-timer (Optional) Draining Safety Devices Servicing and Maintenance PAGE No.
Introduction The 23c boiler is a wall mounted modulating combination boiler with electronic ignition providing central heating and instantaneous hot water. and preferably adjacent to the appliance. It should supply the appliance only and be easily identifiable as so doing. Alternatively, an unswitched shuttered socket outlet and 3A fused 3 pin plug, both to the current issue of BS1363 may be used provided that they are not used in a room containing a bath or shower.
1 - On/Off switch 2 - Central heating temperature selector 3 - Domestic hot water temperature selector 4 - Pressure gauge (bar) and temperature gauge (ºC) 5 - Fault display (faults indicated by a red flashing light) 6 - Clock-timer (Optional) 2 9084 Controls and Lighting 5 4 1 6 3 Diagram 1 1. Lighting the boiler : 4. Heating temperature adjustment : Make sure that: • Winter: Set the control knob between • The boiler is connected to the electrical supply. • The gas service cock is open.
Clock-timer instructions for use Optional Clock-timers inclusive of installation and user instructions:- These are available from your nearest stockist. Electro/Mechanical Part No. 4000122022 Digital Part No. 4000120494 Draining Protection against freezing The boiler has a built in frost protection programme as long as the electricity and gas are left switched on. If the temperature within the appliance falls to 3˚C the burner and system pump are activated.
Safety Devices The 23c incorporates a visual fault display that indicates certain fault conditions, (red flashing light) should they occur. If the gas supply is interrupted Should the boiler fail to operate during Commissioning, the most likely fault is that the gas supply to the boiler has not been turned on or purged sufficiently or that there is no pressure in the heating system. Air in pipes The boiler switches over to safety mode, the red light will flash.
1 Technical Data Heating Heat input (max) NET Q Electrical 25 kW 85,300 BTU/H Electrical supply Electrical rating Level of protection Fuse rating Heat input (min) NET Q 10,4 kW 35,490 BTU/H Heat output (max) NET P 23 kW 78,480 BTU/H Heat output (min) NET P 8,7 kW 29,670 BTU/H Efficiency - Sedbuk D 79,90% Maximum heating temperature 87° C Expansion vessel effective capacity 5l Expansion vessel charge pressure 0,5 bar Maximum system capacity at 75°C 110 l Safety valve, maximum service pressure 3 bar Natu
Bypass fully shut 2 Open 1/4 turn 3 4 5 Open 1/2 turn Open 1 turn Open 2 turns 10086 1 Available pressure (kPa) between heating supply and return lines 1 Technical Data 1 50 2 40 3 30 4 5 20 10 0 500 1000 Flow rate through heating system (I/h) (10 kPa = 1 m WG) Diagram 1.
3 Heating System Design • The 23c is compatible with any type of installation. an average temperature of 75°C and a maximum service pressure of 3 bar. This pressure setting can be modified at commissioning stage if the static head differs. An additional expansion vessel can be fitted to the system if required, see diagram 8.2. • Heating surfaces may consist of radiators, convectors or fan assisted convectors.
12 - Ignition module. 13 - By-pass. 14 - Gas valve. 15 - Loss of water sensor. 16 - Domestic hot water thermistor 17 - Automatic air vent 18 - Domestic water flow sensor 19 - Filter cold water inlet 20 - Filling system 21 - Discharge safety valve (3bar) 22 - Heating filter 23 - Drain valve 9321 1 - Fan. 2 - Air pressure switch. 3 - Heat exchanger. 4 - Overheat thermostat. 5 - Combustion chamber. 6 - Expansion vessel. 7 - Ignition electrode. 8 - Burner. 9 - Flame sense electrode. 10 - Pump.
6 Boiler Location, Flue and Ventilation If the appliance has to be stored for any length of time before installation it should be kept in a safe place where it will not be a hazard to persons or obstruct any access. 6.2 Terminal guard 6.1 Clearances The position of the boiler must be such that there is adequate space for servicing. If a terminal guard is required, it must be positioned to provide a minimum of 50mm clearance from any part of the terminal and to be central over the terminal.
7 Fixing Jig Pack LEFT HAND SUPPORT BRACKET Other components within the fixing jig pack. F - Hanging bracket G - wall template H - copper connections J - sealing washers and screws 9717 9897 The fixing jig is made up as follows: A - Heating return fitting with isolating valve (v). B - Cold water inlet fitting with isolating valve (m). The cold water inlet restrictor supplied with boiler is fitted when the boiler is installed. Refer to Section 9. C - Heating flow fitting with isolating valve (q).
8 Piping System Installation 8.1 Fixing jig, see diagram 7.1 10038 • Remove the contents of the fixing jig pack. • Secure the left and right hand support brackets to the isolating valve plate with the securing screws (2 OFF) supplied. • Connect the five copper connections and sealing washers to the isolating valves. 1 Heating system connections - Pipe diam. 22mm 165mm 2 Hot water system connections - Pipe diam. 15mm 3 Gas connection - Pipe diam. 15mm 8.2 Wall template 20mm MIN.
8 Piping System Installation To avoid low gas pressure problems, it is recommended that the 15 mm gas supply on the boiler is connected to using 22 mm pipe (as close as possible to the boiler within 1 metre). Gas Safety (Installation and use) Regulations In your interests and that of gas safety, it is the law that ALL gas appliances are installed and serviced by a competent person in accordance with the above regulations.
10 Flue Installation Telescopic and Standard The Telescopic flue, (adjustable without cutting) is suitable for installations that require a flue length from 425 minimum to 659.5 maximum. There are no extensions or bends available for this flue. 10.3 Flue systems side Telescopic Flue Extend to suit flue length required. Standard Flue, Refer to diagram 10.1. 10.4 Flue cutting.
10 Flue Installation Telescopic and Standard 10.5 Installation of telescopic flue assembly • For flue systems less than 1,5 m long, fit the restrictor (a) in the fan outlet, see diagram 10.7. • The elbow must be removed from the air and flue duct pipes. • Remove the backing from the self adhesive gasket (H) and carefully fit gasket to base of flue elbow.
10 Flue Installation Telescopic flue system (rear and side) The maximum permissible length (L) for the telescopic flue system is 659.5mm. The restrictor (a) must be fitted to inside the fan outlet. L FLUE RESTRICTOR (a) 10094 GASKET 65 165 Diagram 10.6 Standard flue system (side only) The maximum permissible length (L) for the standard flue system is 3.0m. For flue systems up to 1.5m. the flue restrictor (a) must be fitted inside the fan outlet.
11 Electrical Connection Warning. This boiler must be earthed 11.2 External controls - Mains Voltage All system components must be of an approved type. Remove the MAINS VOLTAGE HEATING CONTROLS CONNECTION PLUG from the fittings pack and install on the 230V interface control board as shown on the instruction sheet, also provided in the fittings pack and diagram 11.2 Electrical components have been tested to meet the equivalent requirements of the BEAB.
12 Commissioning Please ensure the “Benchmark” logbook is completed and left with the user. The commissioning and first firing of the boiler must only be done by a qualified registered person. Gas installation It is recommended that any air is purged from the supply at the gas inlet test point on the gas valve, see diagram 12.1. 9972 Filling the system 1 to 8 1. GAS INLET TEST POINT Make sure that: • The boiler is connected to the electrical supply. • The gas service cock is open.
6. • Leave cap on automatic air vent on top of pump open. Ins 061a 5. • Bleed each radiator to remove air, ensure all bleed screws are re-tightened. • If necessary repressurise the system, refer to procedure 4 9973 12 Commissioning ➜ 8. • Ensure the display indicates a system pressure of 1.5 bar adjust if necessary. Ins 062a 7. • Open various hot water taps to bleed system 9696 ➜ • Adjust heating temperature to maximum .
14 Settings 9975 Bypass A The 23c boiler has a built-in bypass. This must be adjusted according to the requirements of the system, refer to the flow rate pressure curve (diagram 1.1). The boiler is supplied with the built-in bypass open a half a turn. It is adjusted by turning the bypass screw (a), see diagram 14.1. Turn the screw clockwise to close the bypass.
15 Routine Cleaning and Inspection To Drain the Domestic hot water circuit • Turn on one or more hot water taps. To Drain the boiler • Close isolating screws on the isolating valves (b), (c) and (d) turn from vertical to horizontal to close. • Turn on one or more hot water taps. (d) (c) COLD WATER IN (b) HEATING RETURN Diagram 15.2 9977 Note: Isolating cocks water and gas are shown in the: OFF position 9976 HEATING FLOW (a) 9836 • Open the boiler drain valve (a).
15 Routine Cleaning and Inspection 15.6 Side panels (for ease of access if required), refer to diagram 15.4. 15.13 Central Heating Filter, refer to diagram 15.11. • Support the side panels as you remove them. Remove the filter retaining clip and filter clean or renew if necessary. • Unscrew and remove the three retaining screws from front of each side panel. Refit the filter, ensuring the correct orientation. The flat and hole in the filter as shown. Secure with retaining clip.
BURNER RETAINING SCREWS FLUE HOOD 9985 9983 9982 15 Routine Cleaning and Inspection 9986 9981 BURNER GUIDE EARTH LEAD HEAT EXCHANGER DOMESTIC WATER INLET FILTER HOUSING Diagram 15.9 CLIP 9987 POWER SUPPLY LEADS 9984 Diagram 15.7 AIR PRESSURE SWITCH SENSING TUBE ➜ PULL DOWN FILTER Diagram 15.8 RETAINING CLIP Diagram 15.10 9835 9834 FAN RETAINING SCREW FLAT FILTER Diagram 15.
16 Fault Finding Before trying to operate the boiler make sure that : • All gas supply cocks are open and that the gas supply has been purged of air. • The heating system pressure is at least 1 bar. • There is a permanent mains supply to the boiler. • The fuse on the PCB is intact. WARNING. Always isolate the boiler from the electrical supply before carrying out any electrical replacement work. Always check for gas soundness after any service work.
16 Fault Finding COMPONENT NORMAL MEASURE CHECK Gas control valve Resistance of coil 116Ω Under demand during ignition sparks: 24V dc for 1 to 2 seconds, then 12Vdc (constant) at the gas control valve electrical connection. If 0 Volt: the gas control valve is not faulty. If 24 Volts and then 12 Volts but no gas at the burner: Check if the gas control valve is stuck. If not, check the stepper valve. Adjustment valve ( step motor) Close the gas inlet: Dismantle the step motor (screw not sealed in).
16 Fault Finding FAULT: NO HEATING, BUT HOT WATER AT TAPS Is the heating set high enough ? NO The setting is too low or the boiler is set to summer mode. YES Turn the setting up by turning the central heating temperature control knob clockwise. YES Is the room thermostat in demand ? NO Adjust the setting. YES Check by overriding the room thermostat at the connector. Does the fault persist ? YES Check the thermostat, the line, the connections both to the room thermostat and the control board (PCB).
16 Fault Finding FAULT: NO HOT WATER, BUT THE HEATING IS WORKING Is the cold water inlet tap fully open ? NO Open it. YES Is the water pressure greater than 0.5 bar ? Insufficient water pressure. The appliance will not operate. Find out why the pressure is so low. NO YES Check the cold water inlet filter for dirt. Is the cold water tap fully open ? Check the heat exchanger for scaling. Is the water flow rate greater NO than 1.7l/min. (threshold figure).
16 Fault Finding FAULT: THE BURNER LIGHTS, THEN GOES OUT. The flame is spreading across the whole burner, but not being detected. CHECK THE PROBE CHECK THE MAINS With the power turned off, check the resistance between the spark electrode and terminal H23 on the control board (PCB). Check the connector on the end of the wire. Check that the spark electrode is pointing towards the flame. Check the spark electrode. Change it.
16 Fault Finding FAULT: THE RADIATORS ARE LUKE-WARM. Is the installation fitted with a external sensor? YES The temperature of the radiators depend on the outside temperature. If the room temperature is not sufficient, adjust. YES The radiators will only be hot if the thermostat is demanding heat. If the room temperature is not sufficient, turn the setting of the room thermostat up. NO Is the installation fitted with a room thermostat? NO Is the heating setting high enough? NO Turn it up.
16 Fault Finding FAULT: THE FAN DOES NOT START. Does the warning light flash 45 seconds after the start of the demand? Check the power from the room thermostat. Replace the interface board or control board (PCB). NO YES Check the fan (loose terminal connector, windings burnt out). Interface board or control board (PCB). FAULT: THE FAN RUNS BUT THERE ARE NO SPARKS. Does the warning light flash 45 seconds after the start of the demand? NO Thermistor. Control board (PCB).
bk AIR PRESSURE SWITCH FAN g/y 10016 17 Wiring Diagram PLUG br b IGNITOR UNIT IGNITION ELECTRODES SENSE ELECTRODE 3 1 3 4 w WATER PRESSURE SENSOR OVERHEAT THERMOSTAT THERMISTOR CH g w 1 w gn b CHASSIS EARTH GAS CONTROL VALVE br g/y gn or w p y g or gn gn 2 PUMP b THERMOSTAT 2 INPUT (FROST STAT) w g g p w w 230V CONTROLS BOARD FLOW SENSOR THERMISTOR DHW THERMOSTAT 1 INPUT (ROOM STAT) MAINS VOLTAGE EXTERNAL CONTROLS CONNECTION PLUG b FREE * VOLTAGE HEATING CONTROLS CONNE
18 Replacement of Parts To Drain the central heating circuit BOILER DRAIN VALVE • Allow air into the system by opening a radiator bleed screw or the boilers drain valve (a). 9839 • Open drain valve fitted at the lowest point in the system. To Drain the Domestic hot water circuit • Close boiler isolating valve (c). • Turn on one or more hot water taps. To Drain the boiler • Close isolating screws on the isolating valves (b), (c) and (d) turn from vertical to horizontal to close.
18.2 Fan, refer to ‘Section 15.10 Routine Cleaning and Inspection’. 9646 18 Replacement of Parts RETAINING CLIPS 18.3 Air pressure switch Before starting refer to the front of Section 18 Important information. AIR PRESSURE SWITCH • Remove the front panel, refer to Section 15.3. • Lower the control panel, refer to Section 15.4. ELECTRICAL CONNECTORS • Remove the sealed chamber cover, refer to Section 15.5.
18 Replacement of Parts 18.13 Flame sense electrode 18.9 Burner injector assembly, refer to diagram 18.6. Before starting refer to the front of Section 18 Important information. Before starting refer to the front of Section 18 Important information. • Remove burner, refer to Section 15.9. • Remove burner from boiler, refer to Section 15.9. • Remove the right hand side panel, refer to Section 15.6. • Undo the gas supply union nut from under the sealed chamber.
18.14 Heat exchanger, refer to diagram 18.8. 9988 18 Replacement of Parts ELECTRICAL LEAD Before starting refer to the front of Section 18 Important information. CENTRAL HEATING THERMISTOR • Remove the front panel, refer to Section 15.3. • Lower the control panel, refer to Section 15.4. • Remove the sealed chamber cover, refer to Section 15.5. OVERHEAT THERMOSTAT 9994 9995 ELECTRICAL LEADS • Remove the combustion chamber cover, refer to Section 15.7.
PCB (CONTROL BOARD) 10001 10000 18 Replacement of Parts ➜ 10019 230V CONTROLS INTERFACE BOARD ➜ ➜ CONTROL PANEL Diagram 18.10 ➜ ➜ ➜ 9762 ➜ CONTROL BOARD COVER USER INTERFACE BOARD MAINS SWITCH Diagram 18.11 • Unclip control panel user interface and hinge forward . Do not strain the cables. 18.17 User interface board, refer to diagram 18.11. • Disconnect the electrical connections from the mains switch. Before starting refer to the front of Section 18 Important information.
18.20 Central heating pump head, refer to diagram 18.12. 10005 18 Replacement of Parts PUMP ELECTRICAL CONNECTION BOX Before starting refer to the front of Section 18 Important information. • Remove the front panel, refer to Section 15.3. • Lower the control panel, refer to Section 15.4. PUMP HEAD • Drain down central heating water circuit of the boiler only, refer to relevant part of diagram 18.1. Note: it is not necessary to drain down the entire heating system to carry out this work.
18 Replacement of Parts 10008 ➜ ➜ Before starting refer to the front of Section 18 Important information. ➜ 18.24 Water flow sensor, refer to diagram 18.15. • Remove the front panel, refer to Section 15.3. • Lower the control panel, refer to Section 15.4. Drain down the boiler, refer to relevant part of Section 18.1. WATER FLOW SENSOR • Undo the union on the cold water inlet isolating tap. • Pull out slotted metal clip securing filling system tap into housing, swing the tap forwards.
18.27 Automatic air vent, refer to diagram 18.18. 9973 18 Replacement of Parts AUTOMATIC AIR VENT Before starting refer to the front of Section 18 Important information. • Remove the front panel, refer to Section 15.3. • Lower the control panel, refer to Section 15.4. • Drain down the boiler only, refer to relevant part of diagram 18.1. • Unscrew to remove automatic air vent. • After fitting replacement automatic air vent ensure the cap is open. 18.28 Gas Control valve, refer to diagram 18.19.
18 Replacement of Parts • Remove the front panel, refer to Section 15.3. • Lower the control panel, refer to Section 15.4. ➜ IGNITER UNIT • For ease of access remove the left hand side panel, refer to Section 15.6. ➜ ➜ Before starting refer to the front of Section 18 Important information. 10012 18.31 Igniter unit, refer to diagram 18.22. • Disconnect electrical connections. • Remove ignition unit securing screw. ➜ Before starting refer to the front of Section 18 Important information.
19 Spare Parts When ordering spare parts, quote the part number and description, stating the appliance model number and serial number from the data badge. Short parts list No.
Notes Because of our constant endeavour for improvement details may vary slightly from those in the instructions.
