Efm 520 damper question, winter settings

Update, have hot water upstairs in the radiators now. My dad came up and although he doesnt know much about stokers, he pushed water up to the upstairs via the valve above the circulating pump. But we noticed my guage is no longer working and that needs to be replaced now too. I'm also just curious as to why in the world my expansion tank was closed off, I have never touched any of the plumbing until yesterday. I'm just praying for the day all the kinks are worked out, I have a terrible time in the summer with outfires, I ran oil most of the summer. I appreciate this group and the learning experience of all of this, thanks.

Since your expansion tank was closed off your system had no point of pressure change and that is probably why the radiators were empty as the air could not be removed.

It may be that the bladder tank has become defective and the bladder is leaking water into the rest of the housing.

DO NOT buy a chinese gauge. The box they come in will typically say they are tested to national plumbing code standards BUT they do not have the name or address of the manufacturer in china and that makes them suspect.
The replacement 4 inch gauge that was sent to me by keystoker was also faulty.

If you have a Marsh Instruments reseller near you you can pick up or order an American Made square or round 4 inch Marshalltown triple gauge with a bottom or rear mount depending on how your current gauge is set up.. The Marsh instruments triple gauges come with a pedigree of being tested and certified with a warranty as well. And they can be sent back to be recalibrated if the need arises if I remember correctly.

DO NOT use Teflon tape!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Use pipe dope for the gauge threads starting one thread back from the first thread. Teflon tape will interfere with the new gauges ability to correctly sense and transmit the temperature and pressure in your steam chest to the guage face.

Thank you Izaharis! Everything is running nice as of this morning, with the expansion tank still opened. I usually get all my parts from True Value, I have to go see what kind of gauges they have there. I'll keep everyone posted.