Richmond Error Code E1: Sensor Fault

Severity
Warning
Type
digital display
Estimated repair cost: $100 — $250 (parts + labor)
Warning: Your Richmond water heater has detected a sensor fault and has likely shut down to prevent damage. You will have no hot water until this is resolved.

How to Fix Richmond Code E1

  1. Step 1: Turn the water heater off and then back on. This may reset the system and clear a temporary error.
  2. Step 2: Check the wiring connections to the water heater. Make sure nothing is obviously loose or damaged. Do not open the unit.
  3. Step 3: If the error persists after resetting, contact a qualified HVAC technician to diagnose and repair the problem.

How to Reset Richmond Code E1

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. Turn the unit back on. If the error returns, the underlying issue needs repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Richmond Error Code E1 Mean?

The E1 error code on your Richmond water heater indicates a problem with one of the temperature sensors. These sensors are vital for monitoring the water temperature and ensuring the unit operates safely and efficiently. The system relies on these sensors to prevent overheating and to modulate the burner for consistent hot water delivery. When the control board detects a faulty sensor signal (open circuit, short circuit, or out-of-range reading), it displays the E1 error and typically shuts down the unit to prevent potential damage or unsafe operation. There are typically multiple temperature sensors in a Richmond tankless water heater. The E1 code doesn't tell you *which* sensor is the problem. It could be the inlet water temperature sensor, the outlet water temperature sensor, the exhaust temperature sensor, or even the thermistor on the heat exchanger itself. A technician will need to diagnose which sensor is at fault to resolve the issue. Because the unit has shut down, you will not have hot water until the problem is fixed.

Common Causes

  • Faulty outlet water temperature sensor
  • Faulty inlet water temperature sensor
  • Wiring issue (loose connection or damaged wire) in the sensor circuit
  • Defective control board
  • Sensor wire harness disconnected

Diagnostic Steps

If... Check Expected
E1 error is displayed Measure the resistance of the outlet temperature sensor at the control board connector. Resistance should be within the range specified in the Richmond service manual for the measured water temperature. Typically around 10k ohms at room temperature.
Outlet sensor resistance is out of range Inspect the wiring harness and connector for damage or corrosion. Wiring and connector are in good condition.
Wiring is good, and sensor resistance is still out of range Replace the outlet temperature sensor. E1 code clears after replacement.
E1 error persists after replacing the sensor Check the voltage at the control board that supplies the sensor. Stable DC voltage as specified in the service manual (typically 5VDC).

Applicable Richmond Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Outlet Temperature Sensor
Inlet Temperature Sensor
Control Board

Related Codes on Same Models

Other codes that affect the same Richmond model families as E1.

Code Description Severity
11 No Ignition Critical
12 Flame Failure Critical
14 Overheat Warning
16 Outlet Temp Sensor Warning
E2 Dry Fire Critical
E3 Overheat Protection Warning
E4 High Temp Cutoff Critical
E5 Element Fault Warning