BURNERS DO NOT IGNITE WHEN HOT WATER IS TURNED ON
1. Pilot is not on.
Light the pilot. See lighting instructions.
2.Pilot lighting push button not turned to proper position
Be sure that once the pilot flame is on, that the gas valve button ( 
) is slid all the way to the right to the ON position
( 
).
3.Cold incoming water connection made to wrong side of heater
Make sure cold water inlet connection is on the right side of heater when you are facing heater.
4. Water flow rate at hot water tap is too low.
Note: The AquaStar models 38 B require 1/2gallon per minute flow to activate the burners. This is a flow which would fill a quart jar in 30 seconds.
5. Cold water inlet filter on heater is dirty.
Remove the filter and clean. This screen filter is located at the inlet side of the brass water valve (fig. 10, #25). Check and clean faucet aerators too.
6. Crossover in household plumbing
The AquaStar burner activates when there is sufficient water pressure drop in the AquaStar water valve assembly
—ie. when a hot water faucet is opened. If there is a crossover in the plumbing, the necessary pressure drop in the AquaStar will be insufficient, or totally eliminated. A plumbing crossover can be caused by a bad washer at a single lever faucet or incorrect plumbing or a mixing valve in the line, etc. which permits hot and cold water to mix in the plumbing. The crossover will create a back pressure in the system preventing the pressure drop in the Aquastar (i.e. cold water is entering the water heater from both sides and the burners will not come on). To confirm there is no crossover in the plumbing, shut off the cold water supply to the AquaStar. Open your hot water taps. There should not be any water flowing. If there is water flowing, there is a crossover in the plumbing. This is a plumbing problem, not an Aquastar problem. Please contact your plumber.
7.Water valve parts may be dirty or components damaged.
Water valve and component parts must be totally free of dirt. First check that the venturi is free of dirt particles. In hard water areas, mineral deposits can eventually (3 to 5 years in hard water areas) corrode the water valve parts to a point where they will need replacing. Any sign of moisture or corrosion at the joint of the water valve and the gas valve is a sign that the water valve assembly components need to be replaced immediately. Note: Water valve for model 38B is part# 8707002497 for both LP and NG models. (Contact service person to clean water valve or replace if corrosion is present).
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 9 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.
WATER IS TOO HOT
1. Burners too forceful
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
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