WD51/2/1997 The Keston 170 Condensing Boiler 170,000 Btu/h (50 kW) Model Fan Powered High Efficiency Condensing Gas Boiler Installation And Servicing Instructions Keston 170 - GC No 41 930 04 CE No : 87AR50 These instructions must be left either with the user or next to the site gas meter. 34 West Common Road Hayes, Bromley, Kent BR2 7BX Tel. 0181 462 0262 Fax.
WD51/2/1997 The Keston 170 Condensing Boiler CONTENTS Section 1 Description 1.1 1.2 1.3 1.4 1.5 GENERAL INSTRUCTION Description Boiler Schematic Related Documents Performance Data General Data 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.
WD51/2/1997 4.8 4.9 5 Timing The Gas Meter Handing Over To The User 5.1 5.2 5.3 5.4 5.5 5.6 5.7 FAULT FINDING Electrical Control Sequence Fault Finding Flow Chart Continuity Checking Functional Flow Wiring Diagram Electrical Wiring Diagram Illustrated Wiring Diagram Exploded Assembly Diagrams 6.1 6.2 SERVICING Pre Service Checks Recommended Routine Service 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.
WD51/2/1997 Chapter 1 : General Instruction The Keston 170 Condensing Boiler 1. GENERAL INSTRUCTION 1.1 DESCRIPTION The Keston Condensing Boiler is unique in its concept and design. While the application for which the boiler was designed is the same as those which other boilers are used, the Keston boiler has the added advantage of very high efficiency, and small diameter plastic flue which can be extended to 15 metres horizontally or vertically.
WD51/2/1997 Chapter 1 : General Instruction The Keston 170 Condensing Boiler When the return water temperature is below 54oC, part of the water vapour in the combustion products will condense inside the heat exchanger, thus increasing the boiler efficiency by releasing the latent heat of condensation. This condensate falls to the bottom of the heat exchanger where it is separated from the flue gases and exits from the boiler through the condensate drain.
WD51/2/1997 Chapter 1 : General Instruction BS 5440.2 BS 5482.1 BS 7074.1 BS 7593 The Keston 170 Condensing Boiler Air Supply Domestic Propane & Butane Burning Installations Expansion Vessels Treatment of Water in Hot Water Central Heating Systems BS 7671 : Requirments for Electrical Installations.IEE Wiring Regulations 16th Edition. For Timber Framed Buildings, British Gas Publications DM2.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler 2. BOILER LOCATION All dimensions in mm. 2.1 254 DIMENSIONS AND MINIMUM CLEARANCES The boiler must be installed in minimum clearances shown to allow subsequent servicing, and safe operation. SERVICE CONNECTIONS 305 POSITION Figure 2.1.1 The Keston is not suitable for external installation.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler room containing a bath or shower, any electrical switch or appliance control, utilising mains electricity, should be so situated that it cannot be touched by a person using the bath or shower. Compartment installation is permitted - such compartments must be constructed in accordance with BS 6798. The wall on which the boiler is mounted must be of suitable load bearing capacity and must be non-combustible.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler unswitched three pin plug and a shuttered socket-outlet, both complying with the requirements of BS 1363. The appliance must be connected to the supply via a fused double pole switch having at least 3mm (1/8 inch) contact separation in both poles, serving only the boiler and the system. The connection point to the mains supply should be readily accessible and adjacent to the boiler, except for rooms containing a bath or a shower.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler Water treatment must be carried out to BS 7593 : Treatment of Water in Hot Water Central Heating Systems. Pump isolating valves must be positioned as close to the pump as possible. a The Keston 170 is suitable for use on open vented water systems with combined feed and vent. b It is preferable for use on sealed water systems, provided the appropriate components required (see Section 2.7.
WD51/2/1997 Chapter 2 - Boiler Connections Expansion Pipe The Keston 170 Condensing Boiler Expansion Tank Minimum 9ft Height Boiler 28mm Minimum Keston Cylinder Valve Pump L/S Valve By-pass Bal. Valve Strainer Valve Rad. 2 Rad. 1 Figure2.7.1 : Open Vented System Diagram 2.7.2 Sealed Systems Sealed systems must be designed in accordance with BS 5449 and BS 7074 Pt1. A typical sealed system is shown in Figure 2.7.2.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler Make -up vessel. Max. capacity of 3 lt. (5pt) Air Vent Hose Union bib tap Non-Return Valve Auto Air Vent Boiler L/S Keston Strainer Pressure Guage Drain Cock RETURN By-pass Bal. Valve HEATING CIRCUIT FLOW Safety Valve Expansion Vessel Hosepipe (disconnected after filling) Pump Double Check Valve Test Cock BS 1010:2 Stop Tap Hose Connector Figure 2.7.
WD51/2/1997 Chapter 2 - Boiler Connections 2.7.5 The Keston 170 Condensing Boiler Air Elimination In the initial charge of water to the boiler system and in all subsequent additions of water to the system some air will be dissolved in the water. As the water is heated the air is driven out of the solution and will collect in high spots in the system. These air bubbles can interfere with pumping and heat transfer and must be eliminated.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler system and a pump selected that is capable of meeting the flow rate required at the total pressure loss generated by the boiler and the rest of the system. The selected pump must comply with BS 1394. It is important to note that the minimum flow rate must be maintained whenever the boiler is firing.
WD51/2/1997 Chapter 2 - Boiler Connections 2.8.3 The Keston 170 Condensing Boiler Slope FLUE c AIR d b a Keston Figure 2.8.2 : Flue & Air Maximum Length Example 'Horizontal' flue outlet pipework MUST slope at least 5 degrees (80 mm per metre run) downwards towards the boiler. Pipework can be vertical. Only swept elbows can be used.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler adapted to face in any direction BUT must not be directed in the region of the air inlet. Dimensions (mm) Flue Terminal Air Inlet A Below openable window, air brick, etc. 300 50 B Below gutters, soil pipes, drain pipes. 75 75 C Below eaves. 300 50 D Below balconies or car port roof. 200 50 E From vertical drain or soil pipes. 75 50 F From internal or external corner. 600 50 G Above ground or balcony or roof.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler All joints other than push-on or plastic compression connectors must be made and sealed with solvent cement suitable for muPVC pipes and conforming to BS 6209: 1982. External wall faces and any internal faces of cavity walls must be made good. 2.9 AIR SUPPLY The Keston is a room sealed appliance and therefore does not require purpose provided ventilation for combustion air. 2.
WD51/2/1997 Chapter 2 - Boiler Connections The Keston 170 Condensing Boiler If only a portion of the boiler's available output is to be used for radiant floor heating a thermal storage tank will improve the boiler's operation and give adequate control of temperature for the distribution system.
The Keston 170 Condensing Boiler WD51/2/1997 Chapter 3 : Installation 3. INSTALLATION OF THE BOILER Read Chapter 2 - Boiler Location and decide upon the position of the boiler. Installation of the boiler is straightforward but consideration must be given to access to allow flue and air pipes to be pushed through walls and ceilings.
WD51/2/1997 Chapter 3 : Installation The Keston 170 Condensing Boiler The combustion air filter will prevent plugging of the burner caused by dirt being trapped in the burners outer mesh. The filter element supplied with the boiler is obtainable from Keston Boilers or its distributors. 3.4 INSTALLING FLUE AND AIR PIPES Remember the flue pipe must slope downwards back towards the boiler and this is best achieved using 92.5o bends.
The Keston 170 Condensing Boiler WD51/2/1997 Chapter 3 : Installation = c. 88 mm Measure, cut and check the air and flue pipes to pass to the exit from the wall(s) or ceiling. Always thoroughly deburr all pipes and, most important, remove shavings from within the pipe. 3.5 d. Assemble, using adhesive, the pipework from the boiler connections to the exit from the first wall/ceiling (remount the boiler if removed). When pushing pipe through walls, ensure grit and dust is not allowed to enter the pipe.
WD51/2/1997 Chapter 3 : Installation 3.6 The Keston 170 Condensing Boiler WATER SYSTEM Connect the flow and return pipework to the boiler. Ensure a detachable coupling is used at connection to the boiler (ie compression fitting) to enable heat exchanger removal if required. Details of system requirements are given in Chapter 2 - Section 2.7 Water Systems. Connections: 3.7 35 mm compression X 35 mm compression. GAS SUPPLY Connect the gas supply to the appliance.
WD51/2/1997 Chapter 3 : Installation 3.9 The Keston 170 Condensing Boiler EXCHANGING A BOILER Before removing an existing boiler add Fernox Supafloc , or equivalent cleaning agent, in accordance with the manufacturers instructions. Open all radiator valves and fire the boiler. When the system is fully heated, shut off the gas supply and drain down the central heating system. Important The Keston condensing boiler contains components which could be damaged or blocked by grease, dirt or solder etc.
WD51/0/1997 Chapter 4 : Commissioning The Keston 170 Condensing Boiler 4. COMMISSIONING OF THE BOILER Important: This condensing boiler contains components which could be damaged or blocked by grease, dirt, solder etc., from the water system. The following commissioning procedures must be followed precisely. 4.1 INITIAL FLUSHING All waterways within the Keston are either copper or high alloy stainless steel.
WD51/0/1997 Chapter 4 : Commissioning The Keston 170 Condensing Boiler c. Loosen the screw in the burner pressure test point (Figure 5.7.3 item 105) on the gas valve and attach a suitable gauge. d. Turn on the electrical supply, setting any external controls to call for heat. e. ON/OFF switch - select 'ON'.
WD51/0/1997 4.6 4.7 Chapter 4 : Commissioning The Keston 170 Condensing Boiler HOT FLUSHING a. Allow the system to heat up, checking for water soundness. b. Follow instructions provided with the cleaning agent, ie Fernox Supafloc. Turn off the boiler and flush the water system while still hot. Thoroughly flush the system with clear water. c. Refill the system using a quality water treatment such as Fernox CP3. For sealed systems, fill to the required Initial Design Pressure.
WD51/0/1997 Chapter 4 : Commissioning The Keston 170 Condensing Boiler Carbon dioxide is a colourless, odourless gas produced by all combustion processes. When the Keston condensing boiler is operating properly carbon dioxide (CO2) levels will be between 8.2 and 8.9% CO2 for natural gas. To measure CO2 levels in the Keston boiler remove the 1/8" plug from the flue outlet pipe inside the boiler (Figure 5.7.2 item 69).
WD51/2/1997 Chapter 5 : Fault Finding The Keston 170 Condensing Boiler 5. FAULT FINDING 5.1 ELECTRICAL CONTROL SEQUENCE When the external controls are calling for heat, power will be fed to the boiler connection strip at terminals L (Live) and N (Neutral). If the ON/OFF switch is also in the ON position the boiler ON lamp (amber) will be illuminated.
WD51/2/1997 Chapter 5 : Fault FindingThe Keston 170 Condensing Boiler 5.2 FAULT FINDING FLOW CHART START Apply Power To Boiler. Is amber switch light on? yes no Is there 230V between terminals SL & N? no Check External Controls. yes no Is the boiler switched on? Switch On Boiler. yes Faulty Switch Neon -Replace. Is the f an running? yes no no Is the boiler thermostat closed? Boiler return is too hot. Allow to cool. OR faulty thermostat Replce.
WD51/2/1997 Chapter 5 : Fault Finding The Keston 170 Condensing Boiler Continued from sheet 1 Does ignition sequence start? yes no no Is lockout light on? Switc h off & if problem persists replace control box. yes Has the Air Press. Switc h changed over? yes Blocked air filter - replace OR Faulty control box - replace no Are tubes and connections to the Air Press. Switch sound? no Correct tube connection yes Is the air press. across the Air Press.
WD51/2/1997 Chapter 5 : Fault FindingThe Keston 170 Condensing Boiler Continue d fro m Sheet 2 Contin ued o n sh eet 2 ye s Is there 230V at val ve Faulty Gas V alve - Replace. no Is there 230V at Gas Low Press. Sw itch ye s Faulty Gas Low P ressure Switc h - Repl ac e no Faulty C ontrol B ox - Replace. Is there a spark present? yes no Is the H T v ol tage present at top of igni tion electr ode? no Faulty C onrtrol B ox - R eplace. ye s no Is the s park gap 4 m m? Replace/Adjust S park Plug.
WD51/2/1997 Chapter 5 : Fault Finding 5.3 The Keston 170 Condensing Boiler CONTINUITY CHECKING T o c h e c k c o n t in u it y c o n ne c t o n e pro b e t o a n e u tr a l an d us e th e o th e r pro b e to c he c k f o r 23 0 V . ST A R T no Is th er e 2 3 0 V a t te r m in a l L ? C h e c k e x te r na l c o n tro ls . ye s Is th er e 2 3 0 V a t th e O N / O F F s w itc h ( b o t h te rm in a ls )? no F a u lty s w itc h - R e p la c e .
WD51/2/1997 Chapter 5 : Fault FindingThe Keston 170 Condensing Boiler 5.
WD51/2/1997 Chapter 5 : Fault Finding 5.
WD51/2/1997 Chapter 5 : Fault FindingThe Keston 170 Condensing Boiler ILLUSTRATED WIRING DIAGRAM ILLUSTRATED WIRING DIAGRAM 7W 51PK Thermal Fuse RAM Control 56R 52BK 53W Flow High Limit Stat G/Y 9 10 92OR 93OR Low Water Pressure Switch Gas Low Pressure Switch 95G G/Y G/Y 91OR 54G Air Pressure Switch Flue Overheat Stat 11W 8W 8W 12B BR PL (room stat ) 91OR G/Y 6BR 5BR 4B 9G 3BR ON/OFF SWITCH FILTER Lockout Lamp Run Lamp 90R W B 12V 8W 7W 6B 10 9 8 7 6 5 4 3 2 1 Relay BR 5R
WD51/2/1997 Chapter 5 : Fault Finding 5.7 The Keston 170 Condensing Boiler Exploded Assembly Diagrams 5.7.1 Boiler Controls Asembly 154 SCREW 04.1.00.78.0 BOILER CONTROLS 158 TR2 THERMOSTAT 17.4.11.00.0 OPTIONAL 106 IGNITION CONTROL 1 PACTROL 04.4.01.00.0 RAM 04.4.01.00.1 156 K170 - 17.4.00.00.0 FUSE ISOLATOR 145 04.4.20.00.0 SECTION 1 SOCKET 112 FUSE 04.4.19.00.0 SCREW 04.1.00.84.0 122 IGNITION CABLE PACTROL 04.4.11.00.0 RAM 04.4.11.00.1 SOCKET 124 RELAY 17.4.04.00.0 RELAY 123 17.4.03.
WD51/2/1997 Chapter 5 : Fault FindingThe Keston 170 Condensing Boiler 5.7.2 Waterway, Condensate & Flue Assembly 51 SCREW 04.1.00.80.1 WATER WAY, CONDENSATE & FLUE ASSEMBLY K170 - 17.2.00.00.0 50 IGNITER 04.2.13.00.1 GASKET 49 IGNITER 04.2.00.28.2 55 GASKET 17.2.00.05.2 56 SCREW 04.1.00.79.1 TEST FITT. 53 PRESS. 04.2.28.00.0 52 SCREW 04.2.00.29.1 47 MANIFOLD 17.2.00.27.2 82 SECTION 3 EXHAUST PIPE 65 17.2.06.00.0 COMBUSTION PLUG 69 TEST 04.2.00.49.1 GLASS 48 SIGHT 04.2.12.00.1 46 GASKET 17.2.
WD51/2/1997 Chapter 5 : Fault Finding 5.7.3 The Keston 170 Condensing Boiler Air - Gas Assembly TEST FITT. 53 PRESS. 04.2.28.00.0 94 SCREW 04.3.00.28.0 AIR-GAS ASSEMBLY K170 - 17.3.00.00.0 100 GAS TEE 04.3.00.34.1 LOW GAS SWITCH 101PRESSURE 04.3.09.00.0 90 GAS VALVE 91 REGULATOR 04.3.07.00.0 SOLENOID 149 MAIN 04.3.07.01.0 92 AIR HOSE CLAMP 17.3.00.07.0 85 AIR INLET FLEX. CONNECTOR 17.3.00.02.0 BLOCK 150 CONNECTOR 04.3.07.02.0 GAS INLET TUBE 93 FLEXIBLE 17.3.07.00.5 ADJ. SCREW 103 AIR 17.
WD51/2/1997 Chapter 5 : Fault FindingThe Keston 170 Condensing Boiler 5.7.4 Casing Assembly 13 SCREW 04.1.00.40.0 14 SCREW 04.1.00.41.0 6 BURNER ACCESS COVER 17.1.00.01.0 CASING ASSEMBLY K170 - 17.1.00.00.0 VALVE 38 GAS 17.1.13.00.0 21 35mm GROMMET 17.1.00.05.0 26 FLOW LABEL 04.1.00.53.1 20 56mm GROMMET 17.1.00.04.0 FLUE LABEL 25 EXHAUST 04.1.00.52.0 2 TOP COVER 17.1.04.00.0 LABEL 28 WARNING 04.1.00.55.0 39 INLET LABEL 24 AIR 04.1.00.51.0 PR. ADAPT. 36 NEG. 04.1.00.62.
WD51/2/1997 Chapter 5 : Fault Finding 5.7.5 The Keston 170 Condensing Boiler Exploded Diagrams Parts Reference List Boiler Controls Assembly (Fig. 5.7.1) GC Number Code E01 074 106 170 084 109 114 076 111 114 077 113 114 078 114 114 079 115 114 080 116 Description Ignition Control Box Air Pressure Switch Electrical Terminal Block On/Off Switch Green (Run) Lamp Red (Lockout) Lamp Pressure Gauge Waterway, Condensate & Flue Assembly (Fig. 5.7.
WD51/2/1997 Chapter 6 : Servicing The Keston 170 Condensing Boiler 6. ROUTINE (ANNUAL) SERVICING To ensure the continued safe and efficient operation of the boiler it is necessary to carry out routine servicing at regular intervals. The frequency of the servicing will depend upon the particular operating conditions, but it is recommended that an annual service should be carried out by a qualified engineer.
WD51/2/1997 Chapter 6 : Servicing The Keston 170 Condensing Boilers Flue Pressure Test Point A Pressure Test Point B Heat Exchanger Shell Flue Overheat Thermostat Combustion Test Point & Pressure Test Point C Burner Heat (From Above) Fig 6.1.1 Pressure Test Point Locations 6.2 vii) Turn on the electrical supply to the boiler (gas still off), wait for the fan to reach full speed. viii) The pressure difference should be below 17 mbar. If not, clean heat exchanger.
WD51/2/1997 Chapter 6 : Servicing The Keston 170 Condensing Boiler d. If necessary, either from visual inspection or a high pressure differential between points B & C in the pre-service checks, clean the heat exchanger using a suitable stiff plastic bristle brush, vacuum out any large particles and flush the heat exchanger with fresh water until the water flowing from the condensate drain is clear.
WD51/2/1997 Chapter 7 : Replacement Of Parts The Keston 170 Condensing Boilers 7. REPLACEMENT OF PARTS INDEX 7.0 GENERAL 7.1 PRECAUTIONS 7.2 ACCESS 7.3 PROCEDURES - GENERAL 7.4 ELECTRICAL 7.4.1 ON/OFF SWITCH 7.4.2 BOILER THERMOSTAT 7.4.3 NEONS 7.4.4 FLOW OVERHEAT, FLOW HIGH LIMIT & FLUE PROTECTION THERMOMSTATS 7.4.5 WATER PRESSURE SWITCH 7.4.6 IGNITION CONTROL BOX 7.4.7 AIR PRESSURE SWITCH 7.4.8 COMBUSTION BLOWER 7.4.9 GAS CONTROL VALVE 7.4.10 GAS LOW PRESSURE SWITCH 7.
WD51/2/1997 Chapter 7 : Replacement Of Parts 7.0 The Keston 170 Condensing Boilers GENERAL The following must always be carried out by a competent/qualified person. 7.1 7.2 7.3 7.4 PRECAUTIONS i) Always switch off the mains electricity supply and disconnect the plug at the isolating switch and socket. (If a switch only is used then remove the fuse.) ii) Gain access to the appliance (Section 7.2) and turn off the gas supply at the appliance service cock.
WD51/2/1997 Chapter 7 : Replacement Of Parts v) 7.4.3 iv) v) vi) vii) iv) v) vi) Isolate the appliance (Section 7.1) Gain access (Section 7.2) Remove the push on connectors from the thermostat taking note of the correct positions. Unscrew the two retaining screws and remove the thermostat. Flue protection thermostat only The thermostat seal is maintained via a small 'O' ring between thermostat and flue pipe. If this is damaged on removal it must be replaced. Reassemble (Section 7.
WD51/2/1997 Chapter 7 : Replacement Of Parts vi) 7.4.7 The Keston 170 Condensing Boilers Reassemble (Section 7.3) Air Pressure Switch (Fig. 5.7.1 item 109) i) ii) iii) iv) v) vi) Isolate the appliance (Section 7.1) Gain access (Section 7.2) Remove the push on connectors from the air pressure switch taking note of the correct positions. Disconnect the union to one plastic tube connection and pull off the second plastic tube from the air pressure switch.
WD51/2/1997 Chapter 7 : Replacement Of Parts ii) iii) iv) v) 7.5 viii) Isolate the appliance (Section 7.1) Gain access (Section 7.2) Unscrew and remove the brass plug from the gas outlet block. Remove the rubber seal from the injector housing. Insert a flat blade screwdriver into the exposed hole and unscrew the gas injector. Check the injector is the correct size for the boiler size and fuel type. Reassemble (Section 7.
WD51/2/1997 Chapter 7 : Replacement Of Parts 7.8 The Keston 170 Condensing Boilers HEAT EXCHANGER (Fig. 5.7.2 item 42) i) ii) iii) iv) v) vi) vii) viii) ix) x) xi) xii) xiii) xiv) xv) xvi) xvii) xviii) xix) xx) xxi) 7.9 Isolate the appliance (Section 7.1) Gain access (Section 7.2) Shut of the water supply to the appliance. Remove the burner head (Section 7.7) Drain the system to below the level of the appliance using the drain off tap at the base of the heat exchanger.
WD51/2/1997 Chapter 7 : Replacement Of Parts 7.11 PRESSURE GAUGE (Fig. 5.7.1 item 116) i) ii) iii) iv) v) vi) vii) 7.12 Isolate the appliance (Section 7.1) Gain access (Section 7.2) Unscrew the sight glass fitting from the burner head. Reassemble (Section 7.3) HT IGNITION LEAD (Fig 5.7.1 item 122) i) ii) iii) iv) 7.14 Isolate the appliance (Section 7.1) Gain access (Section 7.2) Shut off the pressure measurement point at the return drain valve located at the base of the heat exchanger.
WD51/2/1997 Chapter 8 : Spare Parts Listings The Keston 170 Condensing Boiler 8.
WD51/2/1997 Chapter 8 : Spare Parts Listings Item GC No 90 91 Part Denomination The Keston 170 Condensing Boiler Item GC No Part Denomination 375 535Gas Valve Outlet Gasket 375 536Gas Valve 104 114 122Flexible Hose Gasket 106 E01 074 Ignition Control Box 109 170 084Air Pressure Switch 122 E01 075 HT Ignition Cable Installation & Servicing Instructions Page : 49
WD51/2/1997 Chapter 8 : Spare Parts Listings The Keston 170 Condensing Boiler SHORT SPARE PARTS LIST FOR THE KESTON CONDENSING BOILER RANGE Item GC No 19 45 46 49 50 55/104 63 67 71 72 90 91 106 109 122 114 105 114 117 114 118 375 527 114 120 114 122 375 530 375 532 375 533 375 534 114 139 375 536 E01 074 173 084 E01 075 Part Denomination Air Filter Burner Burner Manifold Gasket Ignitor Gasket Ignitor/Sensor Probe Flexible Hose Gasket Boiler Thermostat Flue Thermostat Flow Overheat Thermostat Flow Hi
WD 93/0/1997 KESTON CONDENSING BOILERS IMPORTANT KESTON 170 INSTALLATION KEY POINTS † † † † † † † † † † † † † † † † Read Installation Manual Carefully Ensure that there is at least 9 feet head of water pressure at the top of the boiler. DO NOT remove the dust caps from the air and exhaust pipes until ready to connect. Ensure that ALL dust particles, filings , plastic chips etc. are removed from the inlet pipe. If the installation is a replacement the system must be flushed clean.
