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hot water heating

In our house we have a hot water heat. The problem is the safety valve leaks or dribbles when the boiler runs,so what we did was buy a new one. The valve was put on and we still have the leak. Next we looked at the pressure gage on the boiler, it read at 24lb of pressure when the boiler is running. When it is not running it is 18lb. So we really don't know what to do next. Is there anything we can do Should we hire a professional to fix it? I forgot to let you know how it all started. When I broke the themostat on the wall and the heat was set very high so we think the safety valve my have gone off then for the first time. We put a new digital thermostat on and we have been left with this problem ever since. The boiler is a G.E. System.If you can help we would really appreciate your advice. Thank you.


  • kevin coppinger_4
    kevin coppinger_4 Member Posts: 2,124
    sounds like...

    you could use a pro to realy run the system through. It is probably a blown or water logged expansion tank but you should really not do that by yourself....kpc

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

  • first and foremost i suggest you have a new boiler standing by. the G.E. downdraft was possibly the greatest boiler ever made. it's efficiency is now only being matched forty years later. unfortunatly parts for the burner are unavailable without access to a time machine. your saftey valve issue can be solved by looking above the boiler for cylindrical tank perhaps tucked between the floor joists. this is the thermal expansion tank. follow the half inch line back towards the boiler until you get to a valve. turn valve off. go back to the expansion tank and attatch a hose to the drain on the tank run hose to outside or better still a sink or sump in basement drain tank until empty. open the valve on the way to the boiler you shut. repeat process oct. and march. run GE boiler 'til it'll run no more and consider yuorself lucky to have had it tthis long.
  • Darin_3
    Darin_3 Member Posts: 27

    Welcome to the world of hydronics!!:) You are experiencing page one in the hydronic handbook. A hot water system is in theory, full of water much like a coke can is full of pop. Ever had a can that was left in the car on a summer day explode(literally)? It's the same deal with your boiler only the relief valve prevents the boiler from going BOOM. Instead, it starts to bleed as the pressure approaches the maximum rated pressure of the relief valve(30 psi). Once the pressure gets far enough from the relief valve rating, the leak stops. Remember, fluids grow in volume as temps go from 100 to 180, water cannot be compressed but air can. In a nut shell, the expansion tank(gray steely ball thing) absorbs the growth of the water as the temps go up and down. If there is enough air in the tank, your problem will go away. If your tank is 2 ft by 2 ft roughly you have a bladder tank and it may need replaced(likely) If your tank is larger(1 ft by 3 foot cylindrical) your tank is old school and you need to take some water out of it by closing the valve nearest it and draining some water.
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