To cut to the chase...do the thermostats function like all the others I know of? Full open or full closed are the only two possibilities or is there now a partial open function? TIA!
The thermostat operates on a termanally sensitive spring. It softens when it warms up; allowing fluid pressure on the other side to pass as it gets up to the designated temperature. Any contaminants or rust can impair it's operations. (ie. get it stuck closed, open, or partially open) Hope this help
If you're talking about the one in the hose elbow down by the water pump, I think it functions like all the others I know of. A spring holds it closed, and a pellet of wax trapped in a cylinder expands with heat and pushes it open. It's a slowish effect, nothing sudden about it. The thermostat starts to lift a bit above 80 ℃, definitely opening by 85 ℃. It should be fully open (10 to 14 mm lift) by 95 ℃. House thermostats on the wall, now those frequently are just on / off (though even that has been changing in these modern days of variable-rate furnaces, A/Cs, and heat pumps),
