I have about a 30 year old gas boiler that I'm sure is inefficient and needs the relief valve replaced before this winter, it's so rotted I'm suprised it hasn't leaked. The boiler feeds cast iron radiators in most of the rooms. My bedroom had the rad removed long before I owned the home and had piece of copper fin installed between the supply and return pipes. About 10 years ago I ripped up the floor to move the pipes closer to the wall and farther apert to accomodate a longer piece of copper base board. This room has never been warm. Additionally the second floor bathroom, first floor half bath, kitchen and the laundry room all have toe kick HW heaters installed. Everything is on one zone. The cast iron radiators always work well and provide ample heat. The 3 toe kick heaters on the first floor work well except for the kitchen one that doesn't always kick on. The toe kick upstairs usually works fine although one winter it never kicked on. I bleed the line to it and tested everything but didn't find a problem, then the next season and a few since it functions fine. The second floor toe kick was connected to the piping originally going to a cast iron rad in that bathroom. The 3 toe kicks downstairs are all at the end of the trunk lines.
My thoughts are replacing the gas boiler with an appropriate size unit for the house with a high efficiency rating. In this replacement I want to zone the 2 floors. Is it better to use 2 circulator pumps or 1 pump with zone valves? In the basement I'd like to remove the 1.5" steel supply/return lines and reinstall lines above the support beams and in the joist bays for better head room in the basement. I have no idea what size pipe to use, same size as the steel or can I go smaller, planning on using copper, I think! Is there a way to connect the toe kick heaters to insure 100% operation? Would it be OK to switch out my bedroom copper fin to cast iron base board? There's a start to my questions.
FWIW, I am a licensed home improvement contractor. I don't do much HVAC for my customers other than maybe adding a duct during a remodel job. However, I installed central air on the second floor of my home and a forced air (propane) heat in my garage, which both work very well.
Thanking you all in advance for any input and help.
Last edited by Rex; 08-19-2009 at 08:23 PM.