Review on The MotoRad 7302-170 Fail-Safe Thermostat: Reliable Temperature Control You Can Trust by James Prizgint

The temperature control in my 2011 Ridgeline has been stable for 4 months. Then the "fail-safe" mechanism kicked in when the truck was parked in the garage after an hour on the freeway and wasn't even driving. The photo shows that the "fail-safe" mechanism is clamped on one side, leaving the thermostat partially open. This is how it should work when the engine overheats, but at that time there was no such condition: there was not enough coolant, and the temperature during operation was normal. The temperature of the coolant must rise just enough to activate the "fail-safe" when the circulation stops. That "wrong" answer is the problem. Replaced "fail-safe" with a normal thermostat and no more problems.