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obstruction in baseboard hot water system

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noob
noob Member Posts: 5
I recently installed two new taco zone sentry valves in my dual zone, hot water system.  they are working properly, as is the taco zone controller.  I refilled the boiler and purged the lines to the best of my ability, and the first floor (zone 1) is working fine.  The second zone, upstairs (with a portion of the run through the attic) is not working.  The only way I was able to coax heat up and through the system was to: Turn off zone one; shut off the return valve for water returning to the boiler;  set the cold water filler pressure up a little higher than the system pressure; then turn on the purge valve (there is only one purge valve, both zones run to it).  This seemed to work to get hot water up and into the system, but once turn the purge valve off and the return valve back on, there is no movement of hot water.  I then tried to coax hot water back through again, and this time, with cold water flowing into the boiler, and the return valve off, and the purge valve on, eventually the water purging out of zone two slowed to a trickle, and essentially a stop.  Based on this I am assuming that I have an obstruction somewhere in zone 2, and I can only assume it occurred as a result of the work I did replacing the zone valves and adding some additional shut off valves on each side of the zone valve.  How does a person get rid of an obstruction, if there is one.  Is it possible to diagnose the location?  is there a way to "blow out" the line?  any and all help appreciated  

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  • icesailor
    icesailor Member Posts: 7,265
    edited February 2014
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    Obstructed Pressure:

    See that round thingy on the front of the boiler that says how much pressure there is in the system and how hot the water is in the boiler? Notice that on the "pressure" needle, there is a scale above and below it? See where one scale says "PSI" and the numbers on the other side don't seem to correlate to anything? Well, if it says 12#, multiply the 12 X 2.31 and that is how high the water is in the closed or open system. Measure from the center of the gauge on the boiler to the bottom of the floor above. Measure from the floor of the first floor to the floor of the second floor. Measure the second floor to the attic floor. Add 12". If the total number is the same or less than the first number, and at least 6# higher, you can purge until the chickens go to roost. It won't purge and it won't heat.

    Systems like yours usually need 16# to 18# at a minimum. The pressure reducing/boiler fill valve should have a fast fill feature. Normally, "WE" use that as a by-pass for purging. But the pressure needs to be raised. There should be a tag with a date of manufacturing on it. If it is more than 10 years old, replace the valve with a BRASS VALVE with a fast fill feature. If it is a Watts 1156F feeder and it is painted with a coppery reddish paint, it is a iron valve. Replace it with a new Watts 1156F valve.

    You only need one purge place if the return system is piped properly. Your problem is that you don't have enough pressure in the system.

    Your "Obstruction" is the air that you don't have enough water pressure to push out.
  • noob
    noob Member Posts: 5
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    further information on system

    Thank you for the information and advice.  My pressure regulator is ancient, as is my boiler.  The regulator is painted red, with a screw comming out of the top.  I don't even have a round pressure guage, it is square, and just out of the attached boiler picture.  My house was built in 1864, and so it has very high ceilings -- 11 foot on first floor, 10 feet on second floor -- i would guess the basement is about 8 feet. 

    The system worked, with the exception of the thermsostat and zone valves, and in fact, the issue i was having was 85 degree heat on the second floor.  But granted, i don't know what the pressure in the system was at that time.

    So there are only two ways to manipulate the entirety of the second floor run -- a bleader valve in the attic, picture attached, and a screw-type bleeder adjustment on the end of one radiator, which radiator is at the very end of the second floor run.  Obviously the bleeder on the radiator (if that is the proper name) needs to be closed.  But i'm not sure what the position of the attic bleeder should be-  its got the schrader valve in it.  Do i seal that when attempting to get water back into the system?  leave the cap loose to allow air to escape?

    I'm gratified to think that my only obstruction is air.  I truly hope that is the case!!!!!
  • Zman
    Zman Member Posts: 7,578
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    Air

    Ice has you going in the right direction.

    You really cannot even start this process until you have a functioning prv/fill valve and pressure gauge.

    Pictures from farther back would help.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • noob
    noob Member Posts: 5
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    pictures and pressure

    So over my lunch break, I went home and turned the nut on the water pressure regulator, turned the return to boiler valve to off, and opened the purge valve.  I seemed to increase my system pressure from probably 12 to just under 20, and i kept it above 15 while purging, and when i ran out of time -- but not air, i closed the purge valve, reopended the return valve, and backed off the water pressure regulator.  When i left, the pressure was maintaining between 15 and 20.  Is this the proper way to regulate water pressure in my system?  Pics are: 1) the starting pressure; 2) Bell and Gosset pressure regulator; 3) view of the system and the relief tank which looks like no other tank ive seen and has only a drain valve from it -- nothing for air; and 4) final pressure reading. 
  • Zman
    Zman Member Posts: 7,578
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    Air

    It looks like you have the pressure under  control.

    The expansion tank over the boiler is not a bladder style,so you should not be leaving any air elimination devices open.

    You should be able to manual bleed the radiator. The air eliminator in the attic should allow air to escape when you loosen the cap. Tighten the cap when you are done. It may be munged up and will not allow anything out, in which case you should replace it.

    Is the circulator pumping towards or away from the expansion tank? This seems like a minor detail but is critically important when trying to get air out of a system.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • noob
    noob Member Posts: 5
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    Thank you!

    adding pressure seems to have done the trick, upstairs is actually heating all on its own, like it should.  I can hear a lot of air in there, so I will need to do some more purging, but that may come over the weekend.  I will take a picture of my circulator and expansion tank.  The circulator is on the "back" of the boiler, on the return side, just outside the boiler, so feeding water into the boiler.  The expansion tank is on the "front" of the boiler, seemingly unconnected to the line bringing heat up from out of the boiler and into the house.  as you can see in the picture I posted, the expansion tank and pressure release valve "t" out of the front of the boiler, while the hot water line coming out of the boiler is in the back center of the boiler.  does any of this make sense?  Anyway, I can't tell you what a load off my mind this is to have the heat running again.  I feared the money I saved from installing the zone valves (I was quoted $1600 for valves, controller and lots of ball valves) would be eaten up chasing something I let loose into the system. 
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
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    It's time

    You may want to seriously consider replacing your boiler. Aside from it's age and reduced efficiency, the existing expansion tank could be waterlogged and prevent adequate fill pressure, even if the fill valve was replaced. It's cold and probably impractical in the middle of a cold winter, but without a repipe, you may get very frustrated.
  • stufine
    stufine Member Posts: 13
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    Are you missing

    a clean out cover on the chimney? Below the water heater flue.