Starting at 170 is quite a shock to the wood. And who knows how accurate the control is in the oven. Might be 190? You can put an automotive trouble light in the oven and easily get it to 100 degrees with just the light bulb as a starter. The sterilization process requires 133 degrees in the center of the wood. Most sterilization cycles are run at 150 degrees. I've dried a lot of wood in my house attic. Gets real toasty up there and cools each evening. Pretty much a solar kiln up there! Also a circulating fan is the way to go for even heating of the wood. Otherwise one side closer to the heating element can go much higher than the other and set up an imbalance.