AquaStar NG - Manual (Page 15)

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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 “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 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 30-50 psi (2.07-3.45 bar). Confirm that
the pressure tank is not water logged.
4. Insufficient gas pressure
Check gas pressure requirements (page 2) and consult gas
service person.
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 shut-off the gas. Rebuild the water valve assembly repair
kit from BBTNA (part#8 703 406 204).
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.