Rheem RTG74 User Manual

SVC 810 Tankless Troubleshooting Manual
32
Error Code 65 (RTG66 Only)
Explanation: Water Volume Control fault. At a minimum check the following:
1. Verify there is water flow thru the unit even if the unit does not fire.
2. Access maintenance information to determine flow rate.
3. Check all wiring connections to the water control and connector B on the Printed Circuit
Board.
No
Yes
The water heater appears to be
normal. Attempt to operate
again.
Is there any
pulse output
from the Fan
Motor?
Re
p
lace Fan Assembl
y
Is there any pulse output from the
Fan Motor? To measure the pulse
output, turn on the fan by pushing
"MAX" (SW2) Button. Measure the
voltage of connector G between
Blue and Yellow wires:
4 to 10 VDC
(p
ulse
)
Re
p
lace Printed Circuit Board
Measure the voltage at connector C between the
Red#7 and Black#8 wires for: 8 to 16 VDC
Measure the voltage at connector C between the White#2 and
Black#8 wires for: 8 to 16 VDC
Is the voltage to
the water
control OK?
No
Replace the Printed Circuit Board
Turn power off;
unplug unit and
then on again.
When motor
operates, is the
voltage to the
water control
OK?
No
Re
p
lace the Printed Circuit Board
Re
p
lace the Water Control Assembl
y
Yes

Rheem RTG74 Specifications

General

Brand	Rheem
Model	RTG74
Category	Water Heater
Language	English