Okay, finally I have success! I'll detail what I did as it might save someone a lot of headache. First off, hot water pipes are thinner than cold water. I think cold water is type M and hot is type L or vice versa. No matter how many times I look that up, I still forget! Anyway, I got pretty good at cutting the thick one but was having MAJOR difficulty cutting the thin one. To make a long story short, I had to use a hand held key saw. Annoying, slow but that worked. Next, stick bread in the lines on both sides to block the water. You think you get all of the water out of the line, but you don't. With water in the line, soldering will be impossible. You'll have to heat the joints three times as long and the solders won't be good. I had leaks by not following this. A step which I knew but still didn't do. Stupid on my part. Okay, no more leaks. Now, I'm supposed to bleed the lines. Although my house was built in the 1930s, we added a large addition and the house is pretty new, including the heating system. It seems that the plumbers are no longer putting bleeders on the line. Mine don't have any. No problem. I should just open up point 1 in pic 2, and the valve on point 9, pic 1 (which you can't see) then open the garden house valve on line 1, pic 2. When the water flows out smoothly with no sputtering, the air is out, right? Well yes, but things just weren't working that way. I did everything I just said and water came out. Within 10 seconds, however, all the water came out and it just dried up! Uh, is that supposed to happen? Confused, I shut the line and waited about 30 minutes while I did other things. I came back and tried again. Same results!!! I had about enough of this plumbing project. Looks like it won and I lost. After about 10 successful projects, I was going to have to call in a plumber. I tried getting the job taken care of with my normal service contract, convinced that it was just a lack of knowledge on my part. I was told that since it was the weekend and they weren't sure the project fell under my normal service agreement, they might have to bill me...at the more expensive weekend rate...of $165 per hour!!! I quickly told the lady I'd figure it out myself. Searching this site, I found the answer. I did everything right except one thing. You have to continually add water to the line so that it keeps flushing the air out. You do that by flipping the little handle on point 5, pic 2. That automatically ensures that the pressure in the baseboards remains at the setting on the reducer by adding water when need be. However, if you open it manually, it will just let the water flow (also pushing the air out with it). If there's air in the line, the pipes aren't going to get hot, so you've gotta get the air out. With each bucket of water I let flow through, more of the line got hot. Three buckets of water later, the water was flowing smoothly and I had heat! Note that by me doing what I did, I introduced air into another zone, so I had to repeat the process for that zone as well. No biggie. Three more buckets later, that zone was working again! Now I don't know if there's a way to work on one zone while not affecting the others. I'll have to examine what I did a little and see if there's a sensible way of doing it. Anyway, hopefully this helps someone.

you’re either referring to the law (in Washington State, anyway) regarding rental properties, or you live in some place that has uber nanny legislators. And seriously? YOU don’t think YOU are smart enough to know what temperature YOU want YOUR hot water in your home? Any who, I don’t want the dishwasher to turn the electrical heating element on. Electricity (unless your using magnetic induction) is an inefficient way to heat water. It is better for my house to use hot water from my tankless HWH. I have a tankless HWH that will produce 190° hot water if I set it correctly. I have a dedicated line from the manifold that natal led between the heater and the Case Acme temperature regulator. I send 160° water to my dishwasher, and washing machine. (I also have a dedicated line that supplies 160° to a separate faucet on my sink that takes the place of the under sink contraption that crapped out a while back. (120° is the legal limit? Don’t tell InSinkerator. I doubt those gadgets they make can even go down to 120°.) I would use 180° water but I am afraid the water temperature alone might melt some plastic ware and also damage some synthetic fabrics. Here’s a thought, when it comes to how YOU choose to live in YOUR house, man up, and grow a pair.

Harvey - a complete repipe will be required to go to hot water heat for a couple of reasons - steam and hot water operate under different pressures, possible leaks from the old pipes/radiators, etc. Hot water systems can be either one pipe or two pipe. No matter what you decide to do, you'll need to hire a very experienced HVAC designer/contractor especially with your needs to separately bill your tenants. There are lots of ways to go with your system - multiple boilers, multiple zones, and on and on. Make sure whoever bids the work does a Manual J heatloss for your property. Hang around the site listed below to get up to speed on what Qs to ask the contractors and what options you have. Good Luck Here is a link that might be useful: Steam - Hot water radiant heat

You are going to use existing radiators? One pipe system or two-pipe? Does your steam system work well (silently, no leaks, even heat)? I don't think that steam is well-suited to temperature set-backs. Is that what you like to do? You have natural gas? If no gas, a heat pump might be a good bet. New England is a climate-diverse area if you are in the extreme part wrt cold, a heat pump might not be appropriate. I think, hot water can give you a more efficient boiler compared to steam. The end efficiency of the hydronic heat boiler depends a great deal on the overall design of the heating system. You must have sufficient radiation to bring down the temperature of the return water to condensing temperature. If your system as a whole can't deliver this, don't install a condensing boiler. It is the wrong tool for the job and will not function well. You might stick with steam if your system can't support an efficient hot water boiler and you don't want to spend a lot to install new rads or ducts. Lastly, finding good steam workers can be tough. If there is a youngster in your area that can handle your system until you die, you will be in luck. There are lots of boiler people at terry love.com and at heatinghelp.com (the wall). Beware, there are lots of steam chauvinists there that will not budge for an efficiency argument. condensing boiler explanation