Trouble description: Facing issue with Cummins Emergency Generator. Radiator water level is going down by

Trouble description: Facing issue with Cummins Emergency Generator. Radiator water level is going down by approx 6L in a week.

No signs of external leakage and radiator leakage. Sump oil has no signs of water mixing.

Exhaust smoke looks okay and generator starts without any problem.

Only started generator for roughly 5 minutes.and coolant heater is set at 45⁰C

Present Status: Still leaking. Unable to find the leak

Update:

1. Checked both side of radiator. Confirmed no leakage.
2. Scavenge manifold checked no trace of water.
3. Preheater set to 30 to check for evaporation