KDB-GOM
Series
- 74 -
14 - 2
Others
Failure
Heating is working but domestic water comes
out cold or does not come out at all.
No
Symptoms and Causes
Solutions
Reference
First, set the room thermostat to the
domestic water position and open the
domestic water tap.
1
The operating lamp does not light up.
- The operating lamp does not light up because
the hot water flow switch is defective. Replace it.
<Fig. 1>
2
It is operating but domestic water
does not come out.
- Open the domestic water tap and measure the
resistance of the hot water flow switch terminal.
If it shows “0” it is normal, if it shows infinite it is
defective.
<Fig. 2>
3
The operating lamp is working but the
heating pipeline is not warm and
domestic water does not come out.
- Replace the 3-way valve if the heating pipeline is
warm, meaning the transition to heating water
supply mode has not been done due to a failure
of the 3-way valve.(check whether the coil is
short circuited and the ball damaged)
- In case there is no heat exchange in the
domestic water heat exchanger, touch the heat
exchanger. One side is very hot and the other
side cold. Replace the domestic water heat
exchanger.
- If symptoms remain after the checking above, it
may be a problem of hot water supply capacity
from the boiler. Check it out.
<Fig. 3>
4
In case hot water does not come out
during operation, tap inlet and
domestic water outlet pipes are
switched, and domestic water does
not come out because hot water flow
switch is not working.
- Check the piping of the switched tap water inlet
and domestic water outlet.
<Fig. 2>
<Fig. 3>
Supply
<Fig. 1>
Room thermostat, FR-5
Operating lamp
Return
Domestic Water
Outlet
Tap Water
Inlet
Hot Water Flow Switch
Measure
resistance
