Noritz ecoTOUGH NRC98-DV Installation Manual

Also see for NRC83-DV: Owner's guide Field manual Installation manual

Contents

Noritz ecoTOUGH NRC98-DV Installation Manual Manual pdf 27 page image

27Recirculation SystemCombination Potable Water and Space Heating SystemCold Water SupplyIsolationKit(*4)Gas SupplyAquastat(*3)Pump Control Signal(*2)Relay for Pump(if larger than 85 Watts)Hot WaterOptional 8-10 GallonStorage Tank(To alleviate cold water sandwich)GlobeValvePump(*1)Expansion Tank(Install accordingto local code)FixturesHot Water ReturnRBWPump120VAC105NeutralGroundLiveSIsolationKit(*1)Gas SupplyBackflow Preventer(optional)CheckValve(*3)Cold WaterSupplyOptionalExpansion Tank(*6)Mixing Valve(*5)Hot WaterPump(*2)Flow Switch(*4)FixturesAir HandlerNotes:1. Size the pump to provide a maximum of 2 GPM(7.5 L/min.) through the system at 10 ft (3m) ofhead plus piping losses.Adjust the flow using a globe valve and verify theflow rate with the maintenance monitors.2. Pump Control Signal is the preferred methodto control the recirculation pump.For pumps larger than 85W, a relay connectionmust be used. If the Pump Control Signal is notused, an Aquastat may be used to control thepump.3. Use an Aquastat if the water heater is not control-ling the pump.Set the Aquastat to 10°F (5°C) below the setoutput temperature.4. Noritz recommends the use of an Isolation Kitwith the installation.These kits include an integrated shut-off and serv-ice valve with unions and a pressure relief valve.Notes:1. Noritz recommends the use of an Isolation Kit withthe installation.These kits include an integrated shut-off and servicevalve with unions and a pressure relief valve.2. Size the pump to provide a maximum of 3 GPM(11.3 L/min.) with a head pressure equal to the lossthrough the water heater and Air Handler.3 . Check valve required if it is not included with the pump.4. Set the flow switch to deactivate the Air Handler whenthe domestic hot water flow reaches 3 GPM (11.3 L/min.).Adjust as necessary to prevent cycling.5. If the system requires water for space heating at a highertemperature than for other uses, means such as amixing valve shall be provided to temper the water forthe other uses to help prevent scalding.7. The water heater cannot be used for space heatingapplications only.6. Expansion tank required if a backflow preventer is installed.Use Honeywell Aquastat(Model L6006A or L6006C)Aquastat WiringNORITZCondensingTankless GasWater HeaterNORITZCondensingTankless GasWater Heater12. Plumbing Applications