Temperature Switch

[s/v Jedi]

I'm helping somebody who has some issues with a Northern Lights genset. It shuts down for over temperature. It's probably the thermostat but while troubleshooting, I decided to test the 95C temperature switch and a spare he has using a pot of water on the stove with thermometer and multimeter. I noticed that there is a wax-like substace used as an insulator and there seem to be some "windows" in the housing to check it. This wax is dark red on the old switch and light beige on the new one.

Is this some kind of indicator?

cheers,
Nick.

[s/v Jedi]

Bump... somebody reading this must know the answer

cheers,
Nick.

Originally Posted by s/v Jedi

I'm helping somebody who has some issues with a Northern Lights genset. It shuts down for over temperature. It's probably the thermostat but while troubleshooting, I decided to test the 95C temperature switch and a spare he has using a pot of water on the stove with thermometer and multimeter. I noticed that there is a wax-like substace used as an insulator and there seem to be some "windows" in the housing to check it. This wax is dark red on the old switch and light beige on the new one.

Is this some kind of indicator?

cheers,
Nick.

[S/V Antares]

The "Wax snap switch" is common but you would not see the wax unless you opened it up. Does your friends unit have a switch in the exhaust elbow for the raw water as well? Some do. (see attached)

[s/v Jedi]

Originally Posted by S/V Antares

The "Wax snap switch" is common but you would not see the wax unless you opened it up. Does your friends unit have a switch in the exhaust elbow for the raw water as well? Some do. (see attached)

I don't know if he has but I have that genset on your photo.. at least, the 6kW version.

The problem he had with his genset turned out to be the thermostat as expected. But I was stupid enough not to make photo's of the sensor and the wax visible. The new ones have the same just a different color. It is screwed into the coolant reservoir close the the pump.

ciao!
Nick.