Ideal Boilers Classic FF 250 P Installation And Servicing Manual

8 Classic FF - Propane InstallationGENERALThe system should be vented directly off the boiler flowpipe, as close to the boiler as possible. The cold feed entryshould be inverted and MUST be positioned between thepump and the vent, and not more than 150mm (6") awayfrom the vent connection.There should be a minimum height - 450mm (18") of openvent above cistern water level. If this is impossible referbelow.The vertical distance between the highest point of thesystem and the feed/expansion cistern water level MUSTnot be less than 450mm (18").The pump MUST be fitted on the flow side of the boiler.A suitable pump is a domestic circulator capable ofproviding an 11°C (20°F) temperature differential (e.g.Grundfos UPS 15/50 or equivalent). The vertical distancebetween the pump and feed/expansion cistern MUSTcomply with the pump manufacturers minimumrequirements to avoid cavitation. Should these conditionsnot apply, either lower the pump position or raise thecistern above the minimum requirement specified byCaradon Plumbing Limited.Note.A cold water feed must be available back to the boiler,when all automatic valves are in the closed position (ReferBS. 6798) and when close coupled the feed must not be ina vertical leg.Minimum Requirements3 OPEN VENT SYSTEM REQUIREMENTS - FULLY PUMPED.SystemreturnConnectionsto 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 ventThe Classic range of boilers can be installed inlow head situations by fitting a 'surge arrester'in the expansion pipe as shown.The following conditions MUST be observed:1. The surge arrester must be at least 42mmin diameter x 150mm long, thus ensuring aMINIMUM air gap and a MINIMUM depth ofwater below the static water level (cold) of75mm.2. The static water level (cold) must be at least200mm above the top of the horizontal flowpipe, fitted as shown. The vent connectionMUST NOT be made immediately off thetop of the boiler, as venting is made lessefficient.3. The maximum practical length of 15mmcold feed pipe should be used in order toreduce the effective volume of system waterexpanding into the feed/expansion cistern toa minimum.Note. The pump manufacturers minimumrequirements must be complied with. All dimensions in mm (in.). NB. Imperial dimensions are approximate.4 LOW HEAD INSTALLATIONS