Miura E-01: Miura EX-300 Error Code E-01

Symptoms

Panel display shows E-01, indicating a low water level alarm from the primary level sensor. The boiler has been shut down immediately as this is a critical safety condition. The water level has dropped below the minimum safe operating level.

Possible Causes

Feedwater pump failure or loss of pump suction pressure
Conductivity probe in the water column is coated with scale giving false high reading
Make-up water supply interrupted - city water pressure dropped or valve closed
Blowdown valve malfunction - continuously draining water from the boiler

Troubleshooting Steps

Step 1: Check the water level sight glass on the side of the boiler
If no water is visible, immediately stop all heat input and allow boiler to cool before adding water
Step 2: Check feedwater pump operation - verify pump is running and building pressure
Check pump motor amperage and discharge pressure against nameplate
Step 3: Clean or replace the conductivity probe that monitors water level
Remove probe, clean with fine abrasive, verify resistance reading
Step 4: Verify make-up water supply pressure and valve operation
City water pressure should be above 30 psi for proper operation

How to Reset

To reset E-01: 1) Restore water level to the normal operating level using the manual feed valve. 2) Clean the level sensor probe. 3) On the control panel, navigate to Alarm List and press Enter to acknowledge. 4) Press the Reset button. 5) The boiler will enter its normal start sequence after pre-purge.

Common Replacement Parts

MI-EX-1001: Miura EX-300 water level conductivity probe (Clean quarterly, replace if resistance is unstable)
MI-EX-1005: Feedwater pump assembly, 1 HP, 3-phase (Verify motor rotation direction on installation)
MI-EX-1010: Make-up water solenoid valve, 1 inch NPT (Check strainer for debris if valve is slow to open)

Frequently Asked Questions

Q: How do I clean the water level probe on a Miura boiler?
Shut down the boiler and allow it to cool. Isolate the probe from the water column. Remove the probe and gently clean the electrode surface with fine emery cloth or Scotch-Brite. Do not scratch the Teflon insulator. Reinstall and verify proper operation.
Q: Is it safe to restart the boiler immediately after adding water?
If the boiler has been hot and dry, do NOT add cold water immediately as thermal shock can crack the pressure vessel. Allow the boiler to cool, then add water slowly. If the boiler was recently fired with low water, inspect the vessel for damage before restarting.

Miura EX-300 Error Code E-01