I have a 840 sg ft garage that already has 1/2"pipe in the floor.Want to put in a Electric Hydronic Heater. Wall mounting only. All ready with 110 outlet. I dont know what is needed. Can anyone help with specific details? Picture would help. Thank You

Hello, I live in Duluth MN, and have a heating problem that has been ongoing for a week. It has been looked at by both a plumber and the Water and Gas service department with only partial results. We just had our first night below zero, so I must get this fixed asap. I am a complete novice here, so I will do my best to describe everything. We have a 120 year old, two story farmhouse with a full basement. The heating system is a Wells Mclein natural gas hotwater boiler with Cast iron radiators split into three zones. The zones are controlled by Honeywell Valves. Our first floor kitchen, and a bedroom directly above it is zone 3. Zone 2 is the remainder of the second floor. Zone one is the remainder of the first floor. All of the radiator supply pipes that run to the second floor are inside and exposed in the living spaces. The house is poorly insulated, and in need of new windows. The system was inspected last year with no problems, and generally worked well last year. Before the conclusion of winter last year, I removed the old mercury thermostats and replaced them with new square non digital Honeywell thermostats, and had no problems for the remainder of the season. Anyway, I resisted turning on the furnace for as long as I could, using some nice space heaters that seemed to work pretty well, which is why it is just in the last couple of weeks that I discovered the problem. I finally turned it all on about a couple of weeks ago, and everything seemed ok, but the heat was real weak upstairs, even after bleeding the radiators. After a few days I came home from work and there was no heat at all upstairs, and downstairs was like chernobyl. It was about 110 degrees even though the thermostats were all set at 60. The local Water and Gas service came out and replaced the pump motor. I told them that the upstairs had been very weak, and they told me that I would probably have to bleed more air out of the second floor radiators, but should have heat within a few hours. This was last Friday. I am still not getting any heat at all to my second floor. I bleed the radiators 5-6 time a day and still get air out, but no water. The radiators are stone cold, top to bottom. Everything seems ok on the first floor. I contacted the Water and Gas service again, and asked about the likelyhood of the valve controlling the second floor being faulty. He told me to manually adjust the slide lever at the bottom of the box hard right to see if it helped, and then call back in a couple of hours. I noticed that there was zero resistance to the slide lever on that zone valve, and that the others were very tight. After a couple of hours and still no heat I called back and asked if I could run a multimeter to the valve to see if it is functioning and he mentioned 24 volts. By the way, the other valves are warm/hot to the touch. This valve is BURNING HOT to the touch. I was unable to get a reading for the valve and they agreed to come out the next day. When they came in the next day the repairman spent all of two minutes looking at the valve and told me that because the pipes above and below the valve were hot, that it was functioning correctly. I asked about the tank or anything else that could be the problem, and he said they could do nothing more and that I should call a plumber, because maybe the pipes are frozen? The pipes are all inside the living space, so I highly doubted that. The pressure dial on the boiler looks sort of like a clock. One hand showed 50+ Psi, and the larger hand is on 10. I am not sure exactly what that means. Also, while standing in the basement with only the 2nd floor zone turned on, I could hear and feel a slight vibration in the zone valve. I called a Plumber in, and he told me that because the pipes that supply the water to the second floor radiators were cold on the first floor, that it was most likely not a plumbing problem and it was the mechanical system. I am going freaking CRAZY here. I am getting very concerned because I can not with a good conscience allow my wife and daughter to sleep upstairs with the use of space heaters alone. I am getting desperate because no one seems to know what to do, and I have to get this fixed fast. I don't have a ton of money, and I have already paid out twice and still don't have a solution. Any help or information that anyone could provide would be greatly appreciated.