15
11112014GW
Code 14 Troubleshooting Procedure
Thermal Fuse or Overheat
Inspect the internal components inside the water heater’s casing especially around the heat exchanger
where the copper section meets up with the combustion box. You are looking for discoloration of the
heat exchanger surface in that area.
Note; Code 14 is an indication of overheating and should be taken seriously. There are two components
(bi-metal switches & thermo-fuses) within the product that will cause a code 14. The overheat bi-metal
safety switch is mounted on the heat exchanger either on the top right or left front of that component,
the thermo-fuses wrapped around the heat exchanger. The bi-metal switch in most cases will reset itself
after cooling down once tripped. After the bi-metal switch resets the unit will operate again. If the fault
that caused it to trip is not corrected it will trip again once the temperature range for that switch is
exceeded. The thermo-fuses on the other hand are a one shot device, meaning once blown they must
be replaced. This will require removing the heat exchanger at which point you need to perform a
detailed inspection of all items listed below.
1.
Verify dip switch #5 in the SW2 bank of dip switches is in the “OFF” position. If in the “ON”
position this will cause a code 14 as this switch is used to de-energize (disconnect) the gas valve
circuit. This applies only to the VC, KB models. It does not apply to V, VA, VB or KA products.
2.
Verify the unit is connected to the proper gas type; see rating plate for gas type of unit.
3.
Check to ensure this unit has ever been converted from one gas type to another? If it was
converted verify conversion was performed per manufacturer’s specifications. See conversion
procedure for the model number unit at your location.
4.
Verify proper clearances were maintained around unit and vent terminals.
5.
Inspect the safety circuit wiring harness for loose connectors, damage or broken wires.
6.
Ohm out safety circuit to determine if the bi- switch is open or if the issue is a blown thermo-
fuse.
7.
Verify all dip switches are set per manufacturer’ recommendations, contact Rinnai for details on
proper settings if you need assistance.
8.
WARNING:
You must be qualified to service gas systems before proceeding. Verify force low and
high fire manifold gas pressures, check using a manometer. Procedure for checking these
pressures can be found on the back side of the front cover. If you need assistance contact Rinnai
technical services 24/7 for details on now to check these pressures. You must have a
manometer to check operating gas pressures.
