You may want to have a spare on hand but I wouldn't bother actually replacing it until you have to. The others may go for years before failing.

Yeah, I actually bought one extra. The thing is, this burner is the 2nd one that I use the least, that's why it's weird that it was due to natural worn.

 

this burner is the 2nd one that I use the least,

It is even possible that that is why this one died. There is some cleaning of contacts that can happen when they are operated and bang into each other. It is also possible that that relay had some slight fault from manufacture that led to its early demise. Without a careful autopsy I can't tell.

 

Yeah, you are totally right. I meant, by the way, that it is almost the one I use the least, but that doesn't mean it is not used for weeks. I probably use all of them 4 once a week, but there are 2 that I use the most.

Now that I think about it, there's this one "click" sound or snap that happens if I have one burner on but not at maximum power, in which case it will turn off and on in a cycle. Thanks to all of this problem and the autopsy I did on the relay I believe that snap is these contacts becoming activated by the coil. I guess the one that could wear more is the one that controls a burner that's always below maximum power and is used a lot, meaning it's constantly hitting the contacts.

I guess this is so random, after all.