Boiler display shows LOW WATER or LWCO; burner is locked out and circulators may be disabled.

Safety: Never add cold water to a very hot boiler. Allow the boiler to cool if it has been firing recently. Turn off power before working on controls.

• 1. Check system pressure: On hydronic Energy Kinetics boilers, verify the pressure gauge reads within the normal range (typically 12–20 psi when cool). If pressure is very low, the system may need water.
• 2. Inspect for leaks: Look around the boiler, near baseboards, radiators, and near the plate heat exchanger for signs of water leakage. Repair visible leaks before refilling.
• 3. Restore water level: If equipped with an automatic fill valve, ensure the supply valve is open. For manual fill, slowly add water while monitoring pressure. Do not exceed the recommended pressure.
• 4. Reset LWCO: Some low water cutoff controls have a manual reset button. After restoring water and pressure, press reset once.

If LOW WATER returns or you cannot maintain pressure, contact a technician to check the low water cutoff and expansion tank.