Ideal Boilers Classic FF 340 LF Installation And Servicing Manual

Also see for Classic FF 340 LF: User guide

8Classic FF 340 - 360 LF - Installation & ServicingGENERALMinimum RequirementsNote.The pump manufacturers minimumrequirements must be complied withSystemreturnConnectionsto boiler Inverted coldfeed entrySystemflow topump150 (6")Max15mmColdfeed450 (18")Mimimum450 (18")Mimimum22mmOpen ventFeed / expansioncisternWaterlevel(cold)Surgearrester75 (3)Min.450(18)Min. 200(8)Min.Highestpoint offlow orreturn150(6)MaxMax. practicallengthTo pumpColdwaterlevelFeed / expansioncistern75 (3) Min.FlowReturn22 (3/4)Open ventAll dimensions in mm (in.). N.B. Imperial dimensions are approximate4 LOW HEAD INSTALLATIONSThe system should be vented directly off the boiler flow pipe, asclose to the boiler as possible. The cold feed entry should beinverted and MUST be positioned between the pump and the vent,and not more than 150mm (6") away from the vent connection.There should be a minimum height - 450mm (18") - of open ventabove cistern water level. If this is impossible refer below.The vertical distance between the highest point of the system andthe feed/expansion cistern water level MUST not be less than450mm (18").The pump MUST be fitted on the flow side of the boiler.A suitable pump is a domestic circulator capable of providing an11°C (20°F) temperature differential (e.g. Grundfos UPS 15/50 orequivalent). The vertical distance between the pump and feed/expansion cistern MUST comply with the pump manufacturersminimum requirements to avoid cavitation. Should theseconditions not apply, either lower the pump position or raise thecistern above the minimum requirement specified by CaradonIdeal Limited.Note.A cold water feed must be available back to the boiler, whenall automatic valves are in the closed position (refer to BS. 6798)and when close coupled the feed must not be in a vertical leg.The Classic range of boilers can be installed in lowhead situations by fitting a 'surge arrester' in theexpansion pipe as shown.The following conditions MUST be observed:1. The surge arrester must be at least 42mm indiameter x 150mm long, thus ensuring a MINIMUMair gap and a MINIMUM depth of water below thestatic water level (cold) of 75mm.2. The static water level (cold) must be at least200mm above the top of the horizontal flow pipe,fitted as shown. The vent connection MUST NOTbe made immediately off the top of the boiler, asventing is made less efficient.3. The maximum practical length of 15mm cold feedpipe should be used in order to reduce theeffective volume of system water expanding intothe feed/expansion cistern to a minimum.3 OPEN VENT SYSTEM REQUIREMENTS - FULLY PUMPEDELECTRICAL SUPPLYWARNING. The appliance MUST be efficiently earthed.Wiring external to the appliance MUST be in accordance with thecurrent I.E.E. (BS.7671) Wiring Regulations and any localregulations which apply. For Ireland reference should be madeto the current ETCI rules for electrical installations.The point of connection to the mains should be readily accessibleand adjacent to the boiler, except that for bathroom installations;the point of connection to the mains MUST be situated outside ofthe bathroom.Note.Where a room sealed appliance is installed in a room containing abath or shower then the appliance and any electrical switch orappliance control utilising mains electricity should be so situatedthat it cannot be touched by a person using the bath or shower.See Frame 39 for details.