well made solenoid - accurate OEM part. That wasn't my real problem. The problem was due to a poor fitting of the cylinder valve with no proper lift to start the water flow. Imo, my solution was to stick a very small piece of toothpick in the one-way seat to get the tank valve 1mm higher. Single wall ball valve in saddle works well with flat "stick" in it. The pump should provide a decent pressure from the main outlet hose "to the heater" when running. it circulates water to heat it. 20-20 hindsight - first remove yellow cap and check pump performance, exact nature of failure unknown. repair - glue.