Highflow 400 ELECTRONIC RSF FLOOR STANDING COMBINATION APPLIANCE FOR CENTRAL HEATING AND MAINS FED DOMESTIC HOT WATER INSTALLATION AND SERVICING INSTRUCTIONS Worcester supports the Benchmark code of practice GC NUMBER NATURAL GAS 47 311 61 GC NUMBER LPG 47 311 64 BOILER OUTPUT Automatic Modulating Control Domestic Hot Water and Central Heating Minimum 8.8 kW DHW 11.0 kW CH Maximum 24.
Contents 1. 2. 3. 4. 5 6. 7a. 7b. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. Installation Requirements .......................................... Page 2 General Information .................................................... Page 2 Data Tables .................................................................... Page 5 Siting the Appliance .................................................... Page 8 Flue Terminal Position ................................................ Page 8 Air Supply ...............
compartment door must not be obstructed. If the appliance is to be fitted into a compartment then the compartment must conform to the requirements of BS 6798:1987: Section 6. The clearances specified for installation and servicing must be maintained. A water filter, flow turbine and regulator, nominal flow 18 l/min. to supply water at an average temperature rise of 40°C, are fitted to the mains cold water inlet on the appliance.
necessary. With the system at the temperature set by the heating temperature control, on the facia, the burner will modulate to maintain the required output to the system. If the system no longer requires heat to maintain the desired room temperature, the burner will extinguish. The pump will continue to run for about four minutes to dissipate the residual heat from the appliance through the CH circuit and then switch off. When there is another heat demand the operating sequence will re-start.
3. Technical Data See Fig. 2 and 3. The Data Plate is fixed to the top of the control box casing. Table 1 NOMINAL BOILER RATINGS BOILER ADJUSTED FOR BOILER ADJUSTED FOR (10 minutes after lighting) G20 (Natural Gas) G31 (Propane) MAX. OUTPUT kW 24.0 24.0 MAX. INPUT (net) kW 27.0 26.7 BURNER PRESSURE mbar 13.5 28.7 1.09 3 GAS RATE m /h 2.90 MIN. OUTPUT (CH) kW 11.0 11.0 MIN. INPUT (CH) (net) kW 13.5 13.0 mbar 3.5 6.4 1.45 0.54 BURNER PRESSURE 3 GAS RATE m /h MIN.
Table 4 PUMP HEAD BOILER OUTPUT HEAD MIN. FLOW RATE kW Metres L/min. FLOW/ RETURN DIFFERENTIAL °C 11.0 6.1 11.5 11°C 24.0 5.0 16.
Fig. 2. Appliance cabinet dimensions and minimum clearances required. 1200 Space required for installation 910 Space required for installation 610 Space required under fixed surface Space required for servicing Side View 1310 860 Cabinet Height Wall 10 450 Surface may be fixed after installation.
4.5 If the appliance is to be fitted in a timber framed building refer to the CORGI guidelines and BS 5440. 4. Siting The Appliance 4.6 Minimum clearances must be available for installation and for servicing. See Fig. 4 and Table 8. 4.1 THE APPLIANCE MAY BE INSTALLED IN ANY ROOM ALTHOUGH PARTICULAR ATTENTION IS DRAWN TO THE REQUIREMENTS OF THE CURRENT I.E.E.
7a.8 Water loss must be replaced. The connection should be made in the central heating return as close to the appliance as possible. See Fig. 6. 7a.9 Any make-up vessel installed must be fitted with a nonreturn valve. 7a.10 Repeated venting loses water from the system. It is essential that this water is replaced and the system pressure maintained. 7a.11 The pump is set at maximum and must not be adjusted. 7a.12 Connections in the system must resist a pressure of up to 3 bar. 7a.
7b.4 The feed and vent pipe must rise continuously from the appliance to the feed and expansion cistern. 7b.5 A pressure relief valve is not required on an open vented system. With the pressure relief valve left in position a pipe must be fitted which terminates such that any discharge does not cause a hazard to the occupants or damage to electrical components. 7b.
8. Domestic Water Supply 9. Gas Supply 8.1 The final 600mm of the mains cold water connection to the appliance should be made in copper tube only. 9.1 The boiler requires a gas flow of 2.9m 3/h (NG-G20) or 1.09m 3 /h (LPG-G31). Check that the supply system can accommodate this together with any other appliances connected to it. 8.2 The appliance is suitable for a mains pressure of up to 10 bar. 8.3 The appliance is fitted with a mains supply isolating valve.
10.4 The wiring between the appliance and the electricity supply shall comply with current IEE wiring regulations (and any local regulations which apply) for fixed wiring to a stationary appliance. NB It must be possible to completely isolate the appliance with at least 3mm contact separation in both poles. 10.5 If a room thermostat and/or frost thermostat is to be fitted, refer to Fig.10. These must be suitable for mains voltage operation. 10.
Remove link Neutral Live return Room thermostat Live supply X1 PIN N LIVE IN X1 PIN L Fuse F1 2A Slow Fig. 10. Room/frost thermostats.
The maximum flue length when measured from the RIGHT OR LEFT HAND SIDE of the appliance casing is 950 mm. See Fig. 12.2. The following items are included in this flue kit: 1 – Air duct 1170 mm long (including fixing length inside appliance casing.) 1 – Flue duct 1170 mm long (including fixing length inside appliance casing.) 1 – Balanced Flue Terminal. 1 – 90° Flue Bend. 4 – Fixing screws. 1 – Tube of silicone sealant. 11.
Extension flue lengths may be added horizontally and include a second 90° flue bend providing the total straight length does not exceed 2300 mm when measured from the side of the casing. The flue system must be assembled from the Standard Horizontal Side Flue Kit, extension flue kits and a second 90° flue bend. See Fig. 12. 5. The flue including the second 90° flue bend may be positioned in any horizontal direction to suit the installation. 11.1.
FLUE OPTION 4. See Fig. 12. 4. Draw a horizontal line from the Rear Flue centre point position, previously marked, in the appropriate direction along the wall/walls. If the flue system extends through other walls or the appliance is not installed close to a wall, ensure it remains horizontal. Measure 94 mm from the junction of the walls if the appliance is installed against a wall and make a short vertical line.
Fig. 13. Marking the flue positions for all flue options. Flue Option 6. Centre-line position for horizontal duct Extend the vertical line 250mm approx. above the position for the flue bend Corner Corner Side flue application: Draw a horizontal line from the rear flue centre point position in the appropriate direction Flue Option 3. Rear flue extension centre point position ALL INSTALLATIONS MUST BE COMMENCED BY MARKING THIS POSITION Flue Option 1. Rear flue centre point position.
Fig. 14. Cabinet, facia, control box and flue assembly fixing screws. Fit the flue adaptor into the flue sealing grommet, fully against the stop, located on the rear of the inner casing. Tighten the clamping screw (D) located on top of the inner casing. See Fig. 14. When assembling extension ducts ensure that the ducts are correctly located in the socketed joints. See Fig. 23. Measure the length of the air and flue ducts from the end that will be fixed into the adaptor or flue bend fitted to the appliance.
Fig. 16. Layout of components with expansion vessel in service position. 1 24 2 23 22 21 3 20 19 4 18 17 5 16 15 6 14 13 7 12 11 10 8 9 Facia. Control box. Inner casing cover fixing screws (4). Expansion vessel fixing screw. Expansion vessel flexible hose. Pressure gauge. Expansion vessel hinge. Expansion vessel. Heat bank. Tank temperature sensor. Unvented system thermostat. Domestic water drain cock. Gas service cock. Gas valve. Water diverter valve. Pump. By-pass adjustment screw.
Air duct length = A + 244 mm. Flue duct length = A + 284 mm. Cut the air and flue ducts to length. Do not cut the drilled end of the air duct. IMPORTANT: Fit the flue restrictor ring marked 75 into the flue terminal. See Fig. 24. Assemble the air duct to the flue terminal. Ensure it fits fully into the flue terminal and the restrictor ring is located firmly between the end of the air duct and flue terminal. See Fig. 24. Drill through the holes in the flue terminal into the air duct with the drill provided.
firmly between the end of the air duct and flue terminal. See Fig. 24. Drill through the holes in the flue terminal into the air duct with the drill provided. Apply a smear of silicone sealant to the end of the air duct and fix into the flue terminal using the screws provided. See Fig. 23. Note: Do not apply a smear of silicone sealant around the end of the flue duct that fits into the flue terminal. Fit the flue adaptor to the air and flue ducts and assemble the flue system.
Fig. 20. Flue Option 3. Standard horizontal side flue. Flue Option 4. Extension horizontal side flue. Flue duct = (A + 284) mm Air duct = (A + 244) mm Base outline of appliance marked on floor 90° flue bend 25 A Standard horizontal side flue – Flue Option 2: Dimension A = 1000 max. Front of appliance Distance from the side of the base outline of the appliance to the outside surface of the wall 65 Outside of wall Extension horizontal side flue – Flue Option 4: Dimension A = 3000 max.
Fix each end of the air duct to the flue bends with the screws provided. The flue duct must fit correctly between the flue bends. The duct is trapped between the flue bends and does not require fixing screws. See Fig. 26. Follow the procedure for fixing the assembly to the appliance as described in Section 11.6.2. First flue length from the appliance to the second flue bend. The first flue bend will fit into the flue position located on the rear of the inner casing. See Fig. 25.
ii) A flue restrictor ring may be required. Refer to Section 11.3 to determine the size or whether the restrictor is necessary. iii) A flue adaptor MUST be fitted to connect the flue system to the appliance. Refer to the instructions in Section 11.4. Measure accurately the distance from the rear of the appliance, previously marked on the floor, to the centre of the first 90° flue bend. Dimension D. See Fig. 30. The minimum dimension must not be less than 105 mm. Air duct length = D + 82 mm.
Continue the installation by following the procedure for the flue option chosen. Refer to Section 11.4.1, 11.4.2, 11.4.3. 11.4.3.1, 11.4.3.2, 11.4.3.3, 11.4.3.4, 11.4.3.5, 11.4.3.6 or 11.4.3.7. 11.6 FINAL INSTALLATION. Check that all the water connections and the gas connection have been tightened. Facia Mounted Programmer (where applicable). 11.5 INTERNAL FLUE FITTING. If it is required to install the flue system from inside the building the hole in the wall must be 150 mm diameter.
Fig. 24. Fixing the flue restrictor ring into the flue terminal. Flue terminal Flue restrictor ring. Refer to Section 11.3 for correct size Air duct Fit the flue restrictor ring into the flue terminal. Ensure the air duct is fully engaged in the flue terminal and the restrictor ring is located firmly between the end of the air duct and flue terminal. Drill through the holes in the flue terminal into the air duct with the drill provided.
Fig. 27. Flue Option 6. Extension flue upwards and horizontal using a second 90° flue bend. The two flue lengths, when added together, must not exceed 2300mm Second 90° flue bend Outside wall C Air duct = (B – 166) mm Flue duct = (B – 152) mm Air duct = (C – 58) mm Flue duct = (C – 14) mm B 210mm minimum First 90° flue bend Appliance Fig. 28. Flue Option 7. Extension flue horizontal using a second and third 90° flue bend.
Fig. 29. Flue Option 8. Extension flue upwards and horizontal using a second and third 90° flue bend. The three lengths, when added together, must not exceed 1000mm Second 90° flue bend Outside wall C Air duct = (B - 166) mm Flue duct = (B - 152) mm B 210mm min imum Air duct = (C - 58) mm Flue duct = (C - 14) mm Air duct = (B - 166) mm Flue duct = (B - 152) mm Third 90° flue bend 210mm minimum B First 90° flue bend Appliance Fig. 30. Flue Option 9.
Fig.31. Terminal assembly for internal fitting of the flue. Fig. 32. Rubber sealing gasket Duct and terminal assembly for internal fitting of the flue. Flue centring ring Flue terminal Seal Flue duct Flue terminal Duct assembly Air duct Clamping ring External wall Fig. 33. Gas control valve adjustment. 2 Rubber sealing gasket 1 1 2 3 3 4 4 5 6 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 8 Gas valve. Outlet union. O-ring. Pilot gas pipe. Burner pressure test point. 11 Gas valve solenoid connection.
Primary water will circulate around the appliance. Allow the appliance to operate in this condition for a few minutes. Set the room thermostat (if fitted) to maximum. The water diverter will open to central heating and the appliance will operate. See Fig. 16. Primary water will now circulate around the central heating system. Allow the appliance to operate in this condition for a few minutes. Vent all radiators again during this period until air is cleared from the system.
supplying the hot water to the tap. Shut the tap and the burner will go out, possibly after a short period of time filling the heatbank. Set the programmer, if fitted, to central heating ON, the hot water temperature control to MIN, the heating temperature control to MAX and the room thermostat to MAX. Check that the system is pressurised , the burner will light and, after a possible short period topping-up the heatbank, will supply heat to the radiators. Check that the radiators heat up evenly.
Expected measurements should be between: CO: 0.001 and 0.003%. CO2: 6.7 and 7.0%. After taking the measurement: Disconnect the gauge Replace the sealing cap. Put the facia back in to its normal position. Reset the controls. 13. Instructions to the User Fig. 35. Facia Controls. 6 1. 2. 3. 4. 1 2 5 3 SAFETY: Disconnect the electrical supply at the mains and turn off the gas supply at the gas service cock on the appliance before servicing the appliance. See Fig.16.
14.3 Servicing of Components. When replacing components that use clip fixings, the connections must be fully entered so that the clips can pass completely into the locating groove. The clips must not be forced into place. When a component is replaced or disturbed it is recommended the “O” ring is replaced. The “O” rings can be lubricated with a silicon based grease or glycerine which is non-reactive with the ethylene - propylene nitrile “O” rings. Clean the Fan.
Fig. 36. Inner casing assembly.
side, rear and front sections and discard. Fit replacement fibre insulation pads in the reverse order. Note: The fibre pads are fragile so take care they are not damaged. Ensure the insulation pad fitted to the combustion chamber cover has the pilot observation hole correctly aligned. Reassemble the appliance in the reverse order. Open the valves, fill and re-pressurise the system as described in Section 12.2 Fig. 37. Gas to water heat exchanger.
The spark electrode is held in position with a clip. Ease the clip backwards and remove the spark electrode. Pull off the spark electrode cable at the gas valve and discard the spark electrode assembly. Fit a replacement spark electrode in the reverse order. Check the pilot burner settings and spark electrode gap is 4 to 5mm, as shown in Fig. 40. Reassemble the appliance in the reverse order. Fig. 40. Pilot burner setting. Main burner Main burner centre line 10. Flame Sense Electrode. See Figs.
16. Heat Bank Overheat Thermostat. See Figs. 16 and 41. Surface thermostat with horizontal 4.8mm tabs. Check that the electricity supply to the appliance is turned off. Remove the cabinet front panel as described in Section 14.2 a. Unscrew the two screws and remove the cover. Carefully pull-off the leads at the thermostat. Fig. 41. Tank Sensor and heatbank overheat thermostat. 4 3 2 1 Unscrew the two screws and remove the thermostat. Fit a new sensor in the reverse order.
transferred to the special body. Take care not to mark the mating surfaces. Reconnect the cable and refit the cable clamp. Open the valves, fill and repressurise the system as described in Section 12.2. Reassemble the appliance in the reverse order. 21. Water Diverter Valve and Coil. See Figs. 16, 46 and 47. Check that the electricity supply to the appliance is turned off. Remove the cabinet front panel and lower the expansion vessel as described in Section 14.2 a.
replacement valve. Two of the “O” rings are identical in diameter and cross - section and are required for the outer ports. The third “O” ring is smaller in diameter and cross-section and will seal the centre port. IMPORTANT: Fit the two larger diameter “O” rings into the outer locations on the replacement valve. Fit the smaller diameter “O” ring over the centre spigot on the bottom manifold. Ensure the “O” ring is located correctly against the shoulder on the centre spigot.
pump inlet pipe upwards 10 mm approx. and remove from the bottom manifold. Retain the pipe, plate and screws. To access the water to water heat exchanger the top manifold must first be removed: Unscrew locating screw Nos. 6, 7 and 8 in the top manifold two full turns. Unscrew and remove screws Nos. 9 and 10 securing the manifold to the water to water heat exchanger support bracket. Retain the screws. See Fig. 50. Unscrew the flat faced union securing the manifold to the inner casing pipework. See Fig. 50.
rings to replace any “O” rings which have been disturbed. Use new sealing washers where appropriate. Ensure that all clips and screws are correctly refitted. Open the valves, fill and repressurise the system as described in Section 12.2. Reassemble the appliance in the reverse order. washers. Ensure the orientation of the hose fittings does not cause twisting or crimping of the hose when the expansion vessel is repositioned in the boiler.
Unscrew the L and N mains connection and carefully unplug all the other connections from the board not forgetting the earth tag. Unscrew the 6 fixing screws and lift out the board. Re-assemble the facia assembly in the reverse order ensuring that the control knobs are correctly aligned.. 29. Pressure Gauge. See Fig. 16. Check that the electricity supply to the appliance is turned off. Remove the cabinet front panel as described in Section 14.2 a. Drain the heating circuit as described in Section 15.2 a.
Fig.50. Water to water heat exchanger. CAUTION: There will be a small quantity of water remaining in the pipework and waterto-water heat exchanger. Note: Screw Nos. 1 2 , 5 6 7 8 , 11 12 unscrew two full turns – Do not remove. Screw Nos. 3 4 (Refer to Fig. 31) 9 10, 13 14 15 remove and retain. Ease top manifold downwards 10mm approx. to clear pipework 6 8 7 Unscrew flat face union securing top manifold to inner casing pipework. Remove sealing washer.
Fig. 51. Water to water heat exchanger. CAUTION: There will be a small quantity of water remaining in the pipework and water-to-water heat exchanger Domestic drain clip Ease water to water heat exchanger and bottom manifold out of support bracket and clear of appliance Move assembly upwards 10mm approx.
Fig. 53. Flow turbine, water filter and hot water flow regulator. 1. Mains cold water inlet valve 1. 2. Water filter housing 3. Flat face union fitting 4. Water flow regulator 5. Flow turbine 7. 2. 6. Pipework to bottom manifold 7. Water filter 3. 8. Fibre washer 9. Ensure arrow points downwards 8 10. Fibre washer 11. Flat face union fitting 4. 9. 5. 10. 11. 6. 3 Fig. 54. Control Box. 2 6 1 4 5 1. 2. 3. 4. 5. 6.
16. Operational Flow Diagrams CENTRAL HEATING MODE 230V mains supply to the boiler. 3 minute wait AND Frost thermostat and CH control knob ON OR Room thermostat ON (or link) CH temperature 4°C below set point. AND Green power light ON. CENTRAL HEATING DEMAND CH programme ON (or link) AND Gas valve OFF. CH light ON. Pump ON. Diverter valve ON. CH temperature control ON CH light ON. Pump ON. Diverter valve ON. Ignition Sequence at minimum heat input. CH temperature 5°C above set point.
TANK MODE Pump continues for 3 seconds. Pump pulse for 3 seconds if primary temperature is above 82°C. 230V mains supply to the boiler. Gas valve OFF. HW programme ON Green power light ON. Tank 1°C above set point OR Primary temperature above 89°C. AND HW temperature control ON (NO DHW demand) Tank 8°C below set temperature AND Primary temperature below 90°C. Ignition sequence at minimum heat input. Pump ON. Maximum heat input until tank temperature 3°C below set point then 80% heat input.
17. Fault Finding Note: This fault-finding information is for guidance only. Worcester, Bosch Group cannot be held responsible for costs incurred by persons not deemed to be competent. The electronic control system for this boiler incorporates three lights on the facia. These are used to show normal operating status. But as a secondary function, by flashing, they can also be used to help provide fault diagnostics.
Is there a 230Vac live supply across connector X1 pins L&N? No Check electrical supply to boiler. FAIL POINT C FAIL POINT B FAIL POINT A Yes Has fuse F1 blown? No No Has fuse F2 blown? Yes Transformer likely to be faulty. Replace control board. Yes Likely to be caused by mains 230V parts external to the control board, e.g cable damage, connections to (or faults within) pump, fan (RSF only), gas valve / ignitor or external 230V controls.
Choose the appropriate category below. All water cold in all operating modes. Suspect: Pilot flame only. Remove ignitor unit from gas valve. Measure the resistance across the two outer pins on the gas valve. Is resistance between 6kohm and 9kohm? No Replace gas valve. Yes Replace ignitor unit. Note: It is not possible to reliably check the cross light performance of the burner. In the unlikely event of such a fault, investigate flue problems, burner and injector.
Is the gas supply connected and at the correct pressure? Note: If gas supply has been interrupted it may take some time to purge gas to the pilot assembly. No Rectify gas supply problem. Yes Does the fan run at the start of a demand? No Is there 230Vac at connector X6 pin 4 ? No Is there 230Vac at connector X6 pin 2 ? Yes Yes FAIL POINT F (Ignition Sequence Lockout) No Replace control board. Yes Air pressure switch not resetting. Replace air pressure switch. Repair or replace fan or fan cable.
Does sparking stop when flame is established? Is the pilot flame of good size and covering the sense electrode tip? No Yes Yes Inspect flame sense lead. If o.k. replace control board. Replace control board. Visually inspect all three temperature sensors on the appliance (combustion chamber cover needs to be removed to see the central heating / primary sensor). Are they electrically connected and look o.k.
FAIL POINT I Storage tank has overheated. This is a serious fault. Call Service Engineer. Flue gas detected inside boiler. FAIL POINT J Note 1: It is possible that during extreme weather conditions this fault may occur intermittently. Note 2: Lights will flash until detector thermostat self resets. Is flue correctly installed and free of blockages? No Yes Check air/gas channels in gas/water heat exchanger. Are they free of restrictions? No Yes Replace flue gas safety device (TTB).
18. Component Parts List Key No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 GC No.
6. Re-assemble the appliance using the new injectors and the new burner. 7. Remove the facia and remove the link from the terminals marked LPG on the control board. Refer to Fig. 54. 8. Re-commission the appliance as described in Section 13 and reset the burner pressures. Refer to Table 1. and Fig. 33. IMPORTANT: Set the maximum burner pressure before the minimum burner pressure. The minimum burner pressure to be used is that for the hot water. 19.
BENCHMARK No. GAS BOILER COMMISSIONING CHECKLIST COLLECTIVE MARK BOILER SERIAL No. CONTROLS NOTIFICATION No.
SERVICE INTERVAL RECORD It is recommended that your heating system is serviced regularly and that you complete the appropriate Service Interval Record Below. Service Provider. Before completing the appropriate Service Interval Record below, please ensure you have carried out the service as described in the boiler manufacturer s instructions. Always use the manufacturer s specified spare part when replacing all controls SERVICE 1 DATE SERVICE 2 DATE ENGINEER NAME COMPANY NAME TEL No.
www.worcester-bosch.co.uk Bosch Group Worcester, Bosch Group, Cotswold Way, Warndon, Worcester WR4 9SW. Telephone: 01905 754624. Fax: 01905 753130. Technical Helpline 08705 266241. Worcester, Bosch Group is a trading name of BBT Thermotechnology UK Limited. This booklet is accurate at the date of printing but will be superseded and should be disregarded if specifications and/or appearances are changed in the interests of continued improvement.
