Hi all, about 2:00am this morning I was awaken by the noise of my oil burner running indicating that there was something wrong with the OWB. I get dressed, walk to the basement to look at the temp guage coming from the OWB and it shows a water temp of less than 150. Dang, something going on with the OWB most likely the fire was out. Get my heavy coat and gloves on, go outside to look at the controller and it shows F.O., meaning the fire is out. Open the by-pass door, wait couple of seconds and then open the main door to inspect the firebox. At first I thought the firewood had bridged so I removed it all and noticed a few red hot coals still active so I was careful not disturb them. I press the switch that activates the primary air and I heard try opening but no air flow. I then go the back of the OWB, remove the panels and open the combustion box. Everything looked okay but when I lifted the solenoid arm the plate that's supposed to lift to allow air into firebox did not lift. The bolt that connects to the solenoid was missing, thus the plate couldn't lift so it snuffed out the fire. I go to my work shop where I have extra stainless steel nuts and bolts and replace it. It took all of perhaps 20 minutes to get it going again. Because I didn't disturb those hot coals, it took seconds to have a roaring fire going but it took 2 hours for the water temp to reach 190 from a bit lower than 150. I had turned off the heat in the house to allow the water to heat to the level I chose. After 2 hours I turned everything back on and I'm to report all is warm again. Roger