POWER VTX
®
WATER HEATER
45
PV500-68 06/16
16.1 General Troubleshooting
Symptom
Probable Cause
Corrective Action
Starting
or
Pre-purge Failure
Power Supply
Check fuse and/or circuit breaker.
On-Off Switch
Check if On-Off switch is illuminated when on. If not check panel
fuse or incoming power.
Temperature Control
Check that the operating temperature control is set higher than
the temperature of the water heater.
Remote enable/disable open Enable water heater or place jumper between terminals R1-R2.
Electronic Low Water Cut-off
Check internal ELWCO board for indication of failure. The red LED
indicates a lockout condition. Manual reset is required.
Gas Pressure Switches
(when installed)
Gas pressure switches are attached to the gas train. Check for a
tripped condition indicated by the manual reset button on the
switch. Correct low gas pressure condition at the supply.
High Temperature Limiting
Device
The high limit device is set at 200°F. This device is located at the
control flange on the top head of the tank. A high temperature
condition may be caused by a failure of the Temperature Control
sensors or the circulation pump. This failure requires manual
reset.
Combustion Air blower
Check if fan control relay is closed
Blower motor may have failed.
Air-proving Switch
(if blower is functioning)
Check switch contacts are closed.
Check for 120V at the N.O. side of air switch
Check for 120V at the common side of air switch
Check if switch tubing is connected on both ends
Remote Proving Interlock
When terminal C1 and C2 are used a proving circuit for remote
equipment, failure to close this circuit within the allotted time for
Call-for-Heat will prevent operation and cause an alarm
indication. Check for proper operation and proving of remote
equipment.
Loose Wire Connections
Check connections to all components
Flame Failure
Power Supply
120 VAC is required for operation. Low voltage can cause failure.
Voltage below 110 VAC must be investigated.
Hot Surface Igniter
Check resistance at room temperature and then the amperage
draw during heat-up. Replace if the measured amperage is not
within 3.5 to 5.0 Amps or if measured resistance is not within 40-
100 ohms (at room temperature). Also, check for overheating
condition due to damaged refractory around igniter.
Air-proving Switch
Check if switch is bouncing. Adjust or replace.
Gas Pressure
Check for proper inlet static and dynamic gas pressure, 3.5” WC
minimum.
Combustion
Inadequate flame signal may result from improper combustion.
Adjust to proper CO2 levels. Inability to achieve proper CO2 levels
may be caused by a defective gas valve, a defective regulator or
blockage in the in the burner or combustion air supply.
Grounding
Check for proper ground from flame control to burner housing.
Condensate Accumulation
Check that the condensation path from the heater to the drain is
not blocked.