Maintenance; Troubleshooting - Takagi T-KD20 Installation Manual And Owner's Manual

TURNING OFF THE
APPLIANCE
Close the manual valve on the gas inlet line. Turn off
the power supply.
.

Maintenance

WARNING: Turn off the electrical power
supply, the manual gas control valve, and
the manual water control valve before
servicing.
The unit should be checked once a year or as
necessary by a certified and trained technician.
If repairs are needed, the repairs should be
done by a certified and trained technician.
The following systems and parts should be
checked at least once a year:
1. Venting systems
2. Burners
3. Manual operation of the pressure relief
valve to ensure correct operation.
4. Periodic cleaning of the water filter, refer to
figure below.
5. Heat exchanger. Remove the thermistor
and check for a mineral coating. A mineral
coating on the thermistor requires flushing
the heat exchanger with a descaling
solution. Scale build up will void your
warranty and shorten the life of your water
heater.
GAS SUPPLY TO
Manifold pressure tap
THE

Troubleshooting

Water Isn't Hot Enough
The T-KD20 can burn gas at a maximum input
rate of 195,000 BTUH. This puts a limit on the
possible
capabilities (See flow chart on the last page of
this manual). If the water doesn't seem hot
enough, compare the flow and temperature
that is being attained to the T-KD20 flow vs.
temperature chart. If the unit is not performing
according to the chart, first check that the gas
supply line is sized properly, and that the gas
pressure is within the required range. If the
gas line is fine, check the plumbing for mixing
valves, thermostatic valves, scald protection,
single handled valves or crossed connections.
If the unit is performing in accordance with the
flow chart, then it may be undersized for the
application. If the unit is performing according
to the chart, the output temperature can be
adjusted using the TK-RE01 or with the
dipswitches on the unit (See pgs. 22-23)
It Takes Too Long to Get Hot Water
The T-KD20 takes three seconds to ignite, and
three more to get up to temperature. The rest
of the time needed for hot water to get to a
fixture is due to the length of piping between
the water heater and the fixture. If the unit
seems to be taking longer than six seconds to
initiate, check the filter and flow sensor for any
debris or damage.
The T-KD20 Will Not Initiate
First check the flow rate through the unit. If
the flow is not .75 GPM or greater, the unit will
not initiate.
sensor for any debris or damage.
output temperature
Check the filter and the flow
and flow