elec oil heater tstat

You are better off adding an in line thermostat that is remote from the heat source. I prefer mechanical ones to computerized as it takes not much of an electrical interruption for the "electronic" controls to turn off.

I had a space heater (Hot wire, ceramic and oil don't matter for this post) T-Stat fail due to a power surge.. I got a plug in "In-line" 125 volt T-Stat for about 30 bucks (Since I really liked that heater) and used it till the heater finally bit the final dust.

This unit consists of a plug/outlet body (15 amp) a cord and a box which is the actual T-Stat

I also got a 2nd one (Same source) that's mounted on the outside of a heater that had no T-Stat, Works better, and I mean FAR better than any built in T-Stat I've ever seen.. It is on the air-intake side of the heater (Cool side) so positioned that it is NOT warmed by the heater itself. (Both of them are so positioned) only by the air in the room.. Nice big way overkill rated Micro-Switch comes out the back of the thing.. Works great.

Originally I had it in my house, and it seemed to "honor" the thermostat setting, but the room at home is a lot bigger than the cabin of my trailer.

I know the mass of the oil makes the response slower than a forced air type heater.

Thinking about it more, my new plan is to put a digital thermostat and relay in a box with an outlet and a short cord to plug into the wall. then I can plug the heater into it. That was I don't have to modify the actual heater itself, I'll just turn the tstat to max and let the external thermostat turn it on and off as needed.

Did it ever work better?

Often the thermostats on portable heaters are not very precise because they are so heavily influenced by the heat from the heater rather than the actual temperature of the air in the general area. There's not a whole lot that can really be done about it short of having the temperature sensor located rather farther from the heat source. It may help a good bit to have a fan blowing on the heater to circulate the air around it more.

Since the heater is cycling on and off in response to the thermostat setting, I rather doubt it's damaged.

It would not be an impossibly difficult project to put together a remote thermostat cord setup. You could either wire it through a residential thermostat for electric heating directly, or use a battery-powered digital residential thermostat hooked up with a solid state (or I suppose mechanical) relay and possibly some appropriate power source for the relay control line. The latter setup would allow you to use a small, low-voltage and low power wire between the thermostat and the rest of the setup; a telephone wire, for instance, would work fine and be readily available in various lengths.