Troubleshooting; General - Takagi T-K4U-IN Installation Manual And Owner's Manual

TROUBLESHOOTING

PROBLEM
It takes long time to
get hot water at the
fixtures.
The water is not hot
enough.
<How to connect the remote controller to the water heater>
All pipes, pipe fittings, valves and other components, including soldering materials, must be suitable for
potable water systems.
1. A manual shutoff valve must be installed on the cold water inlet to the water heater between the main
water supply line and the water heater.
The water is too hot. • Is the set temperature set too high? (p. 36-37,39)
2. In addition, a manual shutoff valve is also recommended on the hot water outlet of the unit. If the
The hot water is not
water heater is installed within, or subjected to, a closed loop water system, a thermal expansion tank
available when a
must be installed.
fixture is opened.
The hot water turns
cold and stays cold.
The water heater has a high-temperature shutoff switch built in as a standard safety feature (called a
Hi-Limit switch) therefore a "pressure only" relief valve is required.
• This unit does not come with an approved pressure relief valve.
• An approved pressure relief valve must be installed on the hot water outlet.
• The pressure relief valve must conform to ANSI Z21.22 or CAN 1-4.4 and installation must follow local
codes.
• The discharge capacity must be at least 140,000 BTU/h for the 110U (T-KJr2U) models, 190,000 BTU/h
Fluctuation in hot
for the 310U (T-K4U) models, and 199,000 BTU/h for the 510U (T-D2U) models.
5. Pull the remote's wires through the hole at the bottom of the water heater's casing.
water temperature.
• The pressure relief valve needs to be rated for a maximum of 150 psi (1 MPa).
6. Properly attach the remote's wires to the remote controller terminal on the computer board
• The discharge piping for the pressure relief valve must be directed so that the hot water cannot splash
(No polarity).
on anyone or on nearby equipment.

GENERAL

WATER CONNECTIONS
• The time it takes to deliver hot water from the water heater to your
fixtures depends on the length of piping between the two. The longer
the distance or the bigger the pipes, the longer it will take to get hot
water.
• If you would like to receive hot water to your fixtures quicker, you may
want to consider a hot water recirculation system. (p. 30)
• Compare the flow and temperature. See the charts on p. 54.
• Check cross plumbing between cold water lines and hot water lines.
• Is the gas supply valve fully open? (p. 32)
• Is the gas line sized properly? (p. 19)
• Is the gas supply pressure enough? (p. 20)
• Is the set temperature set too low? (p. 36-37,39)
• Make sure the unit has 120 VAC, 60 Hz power supply.
• If you are using the remote controller, is the power button turned on?
• Is the gas supply valve fully open? (p.32)
• Is the water supply valve fully open? (p. 32)
• Is the filter on cold water inlet clean? (p. 41)
• Is the hot water fixture sufficiently open to draw at least 0.5 GPM
(1.9 L/min) through the water heater? (p. 36)
• Is the unit frozen? (p. 40)
-Pressure relief valve-
• Is the flow rate enough to keep the water heater running? (p. 36)
• If there is a recirculation system installed, does the recirculation line have
enough check valves? (p. 30)
• Is the gas supply valve fully open? (p. 32)
• Is the filter on cold water inlet clean? (p. 41)
• Are the fixtures clean of debris and obstructions?
• Check if the flow rate is too low. (p. 36)
• Is the filter on cold water inlet clean? (p. 41)
• Is the gas line sized properly? (p. 19)
• Is the supply gas pressure sufficient? (p. 20)
• Check for cross connection between cold water lines and hot water lines.
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Troubleshooting
SOLUTIONS
Owner's Guide