AquaStar 170 VP manual Gas pressure too low, Water is TOO HOT, Temperature setting is too high

2. Gas pressure too low

Very low gas pressure may be caused by low delivered gas pressure, by a jammed gas regu- lator or by 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, the pressure will drop sharply, causing the pilot flame to go out. Have a gas service person confirm the gas pres- sure both statically and at maximum Btu input. Specifications for your heater are on page 3.

3.Burners are not shutting down immedi- ately when hot water is turned off

If burners don't shut off immediately when hot water is turned off, the heater will overheat and the ECO will shut off the gas. Replace both parts in the water valve assembly (part #38475, 33071). (See Letter R, Fig 2, page 6).

WATER IS TOO HOT

1. Temperature setting is too high

Unlike storage tank heaters which need to be set at a higher temperature than is needed in order to stretch the volume of hot water by mix- ing in cold water, an AquaStar can be set for the exact temperature needed and give endless hot water without need for mixing in cold water. We recommend setting the temperature selector dial on #4 or #5. For more information, see section on Setting Water Temperature, Page 12.

2.Thermostat is not functioning properly (See #1 under PILOT LIGHT GOES OUT DUR-

ING OR AFTER HOT WATER USE)

WATER IS NOT HOT ENOUGH

1.Temperature dial is set too low Change the setting.

2.Water flow through the heater is higher than the capacity of the AquaStar to heat it

If the AquaStar flow restrictor has been removed, the flow through the heater might be higher than its capacity to heat it. Reduce the flow to a range

within which the heater can maintain tempera- ture. See flow chart on Page 18. AquaStar water heaters have a (removable) flow restrictor to assure that the maximum volume flowing through the heater remains in the range that the heater can heat to a suitable temperature, regardless of how many faucets are being used. This is to ensure that the flow is never higher than what the heater can heat to a suitable temperature. The AquaStar model 170 flow restrictor is set for a maximum of 4 1/4 gallons per minute. Note: In private well installations, the high and low cycling control of your water pump may be set too low or the pressure tank may be water logged.

3.BTU input is too low due to insufficient gas pressure

It is extremely important for a tankless wa- ter heater to have the right size gas line to obtain the correct gas pressure.

See specifications for correct gas pressures on page 3. 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 actu- ally being used. It is imperative that the gas pressure requirement be met exactly. Insuffi- cient gas pressure will directly affect the water temperature. Static gas pressure in the line can be measured at the pressure test nipple located on the AquaStar manual shut-off valve (Letter L, Fig 2, Page 6). Manifold pressure may be tested at the manifold pressure test nipple (Letter G).

4.BTU input is too low due to insufficient gas supply

Make sure your main gas line is fully opened. If using LP gas, minimum size of the propane tank should be 100 pounds for best results.

5.Cold water is mixing with the hot water between the AquaStar and the outlet Check for possible automatic mixing valve in the line or a plumbing crossover (see #6 - MAIN BURNERS DO NOT IGNITE WHEN HOT WATER IS ON).

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