PILOT LIGHT GOES OUT DURING OR IMMEDIATELY AFTER HOT WATER HAS BEEN USED
1. Gas pressure too low
Very low gas pressure may be caused by low delivered gas pressure, a jammed gas regulator or undersized gas lines. If the gas lines are undersized, there may still be the specified static gas line pressure. However when the water valve opens,and gas enters the burners, the pressure could drop sharply, causing the pilot flame to go out. Have a gas technician confirm the gas pressure both static and at maximum Btu output. Specifications for your heater are on page 2.
2. Pilot may be dirty or weak
See Page 12 for instructions on pilot maintenance.
3.Burners are not shutting down immediately when hot water is turned off
Note: If burners don’t shut down immediately when the hot water is turned off, the heater will overheat and the ECO will
4.Water is too hot causing overheat sensor to shut heater down
Reduce burners by sliding gas control to single flame position or set control knob to a lower setting.
WATER IS TOO HOT
1. Burners are too strong
Note: If the inlet water is quite warm, slide gas valve control to single flame symbol ( 
) and the heater will function on a minimum burner output.
2. Temperature selection is too hot
Turn the temperature adjustment knob to the left.
WATER IS NOT HOT ENOUGH
1.Temperature adjustment knob is set too low. Change the setting. Turn the temperature adjustment knob clockwise (to the right).
2.Water flow through the heater is higher than the capacity of the AquaStar to heat it
Reduce the flow demand at the faucet. See flow rates at specific temperature rises on page 2.
3.Btu input is too low due to insufficient gas pressure It is extremely important for a tankless instantaneous water heater to have the right size gas line to obtain the correct gas pressure
See specifications on page 2. Unlike storage tank water 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 10 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 “BURNERS DO NOT IGNITE WHEN HOT WATER IS TURNED ON” paragraph # 6). Where automatic
6. Parts in water valve are dirty or damaged, which will prevent the gas valve from being fully opened.
Water valve maintenance needs to be performed, see #7 under BURNERS DO NOT IGNITE WHEN HOT WATER IS TURNED ON
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 is Turned On”.
3.Inlet water pressure is erratic due to inadequate supply water pressure or saturated pressure tank on well system
For installation on a private well system with the use of a pressure tank, the lowest pressure range setting recommended is
4. Insufficient gas pressure
Check gas pressure requirements (page 2) and consult gas service person.
6 720 606 446 | 15 |