Okay, I have a hot water/boiler system in my house with three zones. The zone for the third floor is always hot, even when the thermostat is turned off. From research and asking around, it appears that the problem is the flow control valve, which is supposed to make sure that hot water doesn't rise when the circulator is off. So here are my questions. One, the stop within the flow control valve is supposed to open when the circulator goes on and close when it goes off. What makes it do this? My guess is that the hot water pressing up against it somehow gets it to go up, but I'd like to know. Second, I've gotta replace this apparently damaged valve. It would seem to me that the process is: 1: Drain the water out of the line somehow. 2: Unscrew (I think) the damaged valve 3: Replace it with a new one (doesn't look like Home Depot sells them, so I'll have to go to a plumbing supply store) 4. Fill the system with new water 5. Drain the air out Now from what I understand, my lines not only have water in them, but also anti-freeze. I think they did this because my pipes froze once during an addition (with nobody in the house) and they didn't want me calling them every second. So I guess I could add water, then ask them to come and add anti-freeze afterwards. Or maybe it's not even necessary. Anyway, any help or directions as to where I can look would be greatly appreciated.

A trip to visit my Mother turned into a weekend of trying to repair her hot water gas boiler (American Standard probably 50 yrs old) It started out as solving the leak from the pump so I replaced with a new motor /pump/circulator (armstrong S25). I then filled the boiler and bleeded the radiators of air. I turned on the circulator and turned up the thermostat and the burners won't fire up. The pilot is on although it appears to be a rapid blue only flame. Although I've heard to replace the thermocouple if the pilot light dosen't stay on, I replaced it anyways. The result - same blue fast flame and burners not firing up. When replacing the thermocouple I also vacumned the inside of boiler and cleaned the orifice (I'm basically doing everything it says in this book...I'm a novice when it comes to heating although I kinda know my mom;s boiler having turned it on for winter many times)...ok so I think the problem may be the thermostat. The book says to test for bad thermostat by running a jumper wire between the two leads...I also tried touching the 2 wires directly (there are only 2 wires that come out of wall to thermostat. The burners don't light up and so now I'm thinking there is some problem with the wiring....that there may be no power. The fuse that powers the circulator is operating and the wires from the thermostat run to the boiler on the side with 2 screws. I'm at a lost as to what the problem can be. What other test could I possibly perform? Inside the biler where the bx cable runs into...there is power as I checked with voltage tester. I know the thermstat wires are low voltage and I was touching them. Could this be a gas problem? The pilot is on so I assume gas is reaching the area but I'm sure there is some gadget that controls the full output of the gas. Does this sound like anything you have dealt with? My mom would have called a heating guy but times are hard and the property taxes have to be paid. Thx for any info