22TemperatureTroubleshooting-2The water is cold when only asingle fixture is open.• The unit will not heat the water if the flow rate is less than0.5 gallons per minute.Open the fixture more or open other fixtures so that a greaterflow passes through the unit, and the unit should beginheating again.Amount of Hot WaterThe amount of hot water at acertain fixture is not constant.• When hot water is demanded at other fixtures, theamount available may be reduced. The maximum flowavailable from this unit is a 45°F temp. rise.for N-069M=6.9 GPM / for N-063S=6.3 GPM• Pressure fluctuations and other plumbing conditions cancause the temperature and pressure at a fixture to beunstable, but it should stabilize after a short time.• There are some types of hot water taps that discharges largevolumes of hot water at first but stabilize after time.• To keep the temperature stable, the heater limits theamount of water that can flow through it to a smallamount initially, but the amount increases over time.The amount of hot water in the tubis less/more than the set amount.• When hot water is used for other fixtures while filling thebath tub, the tub will not fill as much.• If there is water in the tub already, or when filling is stoppedand restarted, the tub will fill more.The flow meter alarm does notsound even when filled to the setamount.• The flow meter alarm is set to sound when hot wateris continuously discharged for the set volume of water.If mixing valves are used, or if cold water is mixed with hotwater at the fixture, the tub will fill more than the settingof the flow meter alarm.Amount of hot water availablehas decreased over time.• Is the water filter clogged? ( p.20)Fluctuations in hot watertemperatures.• Set water temperature at 115°F to 120°F. This will allow youto use a higher flow of hot water thus meeting the minimumflow requirement of 0.5 gpm.• Clean the water filter of any debris ( p.20)