Problem solving
RTG 199 HE – 6 720 811 617 (2016/01)
44
8.7
Noisy burner/heater during operation
1. Sealed combustion leak. Make sure combustion cover is securely
fastened. Ensure the exhaust vent adaptor is properly sealed with
supplied gasket. Leaky seals create improper combustion resulting
in noise.
2. Improper venting. Venting that is unsealed, the wrong material, too
big in diameter or too long in run will result in unstable burner flames
and noise. Ensure venting is in accordance with specifications in
chapter4.3, page 10.
3. Lack of adequate combustion air. Drawing combustion air from a
room area of inadequate size will result in unstable burner flames and
noise. Improper piping of combustion air to the outside or
insufficient space will result in unstable burner flames and noise.
Ensure adequate combustion air is provided from the unit in
accordance with specifications in Section 4.4, page 23 Combustion
Air Requirements.
4. Cross contamination. Ensure that intake and exhaust terminations
maintain required clearances as stated in chapter 4.3, page 10.
Cross contamination between intake and exhaust may cause
unstable burner flames and noise.
5. Lack of gas pressure. Inadequate gas pressure will cause the fuel-to-
air mixture (CO
2
) to be out of adjustment. This will result in unstable
burner flames and noise. Ensure gas pressure is in accordance with
specifications in Section4.15, page 33 Measuring Gas Pressure. A
gas pressure reading is needed to proceed further. Contact your
original installer or a local certified gas technician to obtain this
reading.
6. Verify proper CO
2
readings per chapter7.5, page 39. CO
2
adjustments must be done by a certified gas technician with a
calibrated combustion gas analyzer.
9
Problem solving
9.1
Error code diagnostics
To remove error code from the display, press the reset
button.
Display
Cause
Solution
A2
Fault in the flue gas limiter.
Temperature above 230°F (110 °C)
inside the cabinet.
1. Check continuity of the flue gas limiter (see fig. 79, #11, page 51). Go to steps two
and three to determine flue gas limiter fault and repair it.
2. Check for flue gas leakage around the top and bottom seals of heat exchanger, use
mirror to check around the rear as well as the viewing window.
3. Unplug heater and check that flue gas limiter connector and spade connections are
secure.
4. Check the wiring harness connections on the control board.
A3
Wire harness defect.
1. Check wire harness.
2. Measure resistance on wire harness nearby the rubber grommet, must be 115-120
ohm.
3. Check diagnostic menu > 1P, “Cd” must be showed on the display.
A4
Backflow temperature sensor defect -
happens if sensor is disconnected or
short circuit.
1. Check backflow temperature sensor connection. See fig. 79, #15, page 51.
2. Replace exhaust temperature sensor.
3. Check sensor (ref. page 49, chapter 11).
A7
Outlet temperature sensor fault
(Temperature below 36°F or above
210°F).
1. Check wire connection at outlet temperature sensor.
2. Sensor may trip if water temperature drops below 36°F to protect heater from
freezing conditions. Any damage due to freezing conditions is not covered under
warranty.
3. In areas where water has a high mineral content, periodic descaling may necessary.
4. Check sensor (ref. page 49, chapter 11).
A8
Outlet temperature sensor defect.
1. Check wire connection at outlet temperature sensor.
2. In areas where water has a high mineral content, periodic descaling may necessary.
3. Check sensor.
(Flashing)
A9
Outlet temperature sensor not
sensing expected output
temperature.
(Status message, not an error).
1. Check wire connection at outlet temperature sensor.
2. Check gas pressure. Low gas pressure may prevent the heater from reaching
desired output temperature.
3. Check supply voltage. It must be 120VAC and properly grounded.
4. Possible defective control unit call manufacturer for further instructions.
C5
Bypass valve solenoid damaged or
disconnected.
1. Check wire connection at the bypass valve.
Table 49
* By installer or service technician only.
