AquaStar 38B NG, 38B LP HOT WATER TEMPERATURE FLUCTUATES 1. Unbalanced pressure in waterlines

heaters, the burners of a tankless water heater must be very powerful to heat water instantaneously since they do this only at the time hot water is actually being used. It is therefore imperative that the gas pressure requirement be met exactly. Insufficient gas pressure will directly affect the water temperature at the time of usage. See pages 2 and 13 respectively for correct gas pressure settings and where gas pressures are taken.

4.Btu input is too low due to insufficient gas supply Make sure your main gas line is fully opened. If using LP gas, be sure that the size of the propane tank is adequate to supply the required gas pressure.

5.Cold water is mixing with the hot water between the AquaStar and the outlet

Compare water temperature at outlet of the AquaStar (hold the AquaStar’s outlet pipe with your hand) and at the tap. If these two are very different, check for mixing valve or plumbing crossover (see “MAIN BURNERS WILL NOT IGNITE...” paragraph #6). Where automatic “anti-scald” valves are required by code, lower the temperature setting on the AquaStar as much as possible and balance the pressure between cold and hot water after the AquaStar.

6.Parts in water flow valve are corroded so that the gas passage is not fully opening.

Contact your service person or Controlled Energy.

HOT WATER TEMPERATURE FLUCTUATES

1. Unbalanced pressure in waterlines

The added restriction caused by the Aquastar in the hot water system can result in uneven pressures between the cold and the hot. In such cases when mixing cold water at the tap, the lower hot water pressure may be overpowered by a much higher cold water pressure, which may cause the Aquastar burners to shut down. Make sure faucet aerators or shower heads are free of minerals. Do not add any flow restrictor to the shower head.

2.Cold water is mixing with the hot water between the AquaStar and the outlet

See #6 under “Burners do Not Ignite When Hot Water Turned On”.

3.Inlet water pressure is erratic due to inadequate supply water pressure or saturated pressure tank on well system

Check the inlet water pressure. On a private well, raise minimum pressure setting to 30 psi. Confirm that the pressure tank is not water logged.

4. Insufficient gas pressure

Check gas pressure requirements (page 2) and consult gas service person.

12