Richmond Error Code E2: Dry Fire

Severity
Critical
Type
digital display
Estimated repair cost: $150 — $350 (parts + labor)
Warning: The 'E2' error indicates a 'Dry Fire' condition, meaning the burner is attempting to ignite without water flow. This can quickly lead to overheating and potential damage or fire. Shut down the unit immediately.

How to Fix Richmond Code E2

  1. Step 1: Immediately turn off the gas supply to the water heater. There should be a shut-off valve on the gas line leading to the unit.
  2. Step 2: Turn off the electrical power to the unit at the breaker box.
  3. Step 3: Check that the main water supply to the house is turned on. Then, verify that the shut-off valves on the cold water inlet line to the tankless unit are fully open.
  4. Step 4: If you suspect air in the lines, try opening a hot water faucet somewhere in the house to bleed any trapped air. Let it run for several minutes.
  5. Step 5: Do not attempt to restart the unit. Call a qualified HVAC technician or plumber to diagnose and repair the problem.

How to Reset Richmond Code E2

  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 E2 Mean?

The Richmond tankless water heater displays an 'E2' error code when it detects a 'Dry Fire' situation. This means the unit is trying to fire up the burner, but it's not sensing any water flowing through the heat exchanger. Without water to absorb the heat, the unit can rapidly overheat, potentially damaging components like the heat exchanger itself, the burner, or even creating a fire hazard. This is a critical safety issue, so it's important to address it immediately. The unit will likely lock out and stop operating until the issue is resolved. A dry fire can occur for several reasons, all related to lack of water flow or a sensor malfunction.

Common Causes

  • Water supply to the unit is shut off or restricted.
  • The flow sensor is malfunctioning and not detecting water flow even when it exists.
  • Air is trapped in the system, preventing proper water flow.
  • The water inlet filter is clogged, restricting water flow.
  • The heat exchanger is scaled or blocked, preventing water flow.

Diagnostic Steps

If... Check Expected
Unit displays E2 error. Water supply is confirmed ON. Check the flow sensor signal with a multimeter while water is flowing. Refer to the service manual for the correct voltage range. Voltage signal should correspond to the water flow rate.
Flow sensor signal is absent or incorrect. Inspect the flow sensor for debris or damage. Check the wiring harness for continuity. Sensor should be clean and undamaged. Wiring should have continuity.
Flow sensor appears functional. Measure the water pressure at the inlet of the tankless unit. Pressure should be within the manufacturer's specified range (e.g., 40-80 PSI).
Water pressure is low. Inspect the inlet water filter for clogs. Filter should be clean and free of debris.

Applicable Richmond Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Flow Sensor — — —
Inlet Water Filter — — —
Heat Exchanger — — —

Related Codes on Same Models

Other codes that affect the same Richmond model families as E2.

Code Description Severity
11 No Ignition Critical
12 Flame Failure Critical
14 Overheat Warning
16 Outlet Temp Sensor Warning
E1 Sensor Fault Warning
E3 Overheat Protection Warning
E4 High Temp Cutoff Critical
E5 Element Fault Warning