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Cast iron radiator not getting hot

rpezz50
rpezz50 Member Posts: 13
Hi guys I had my boiler replaced about 6 month ago I now have a Budures g115 with the Logamatic. I have been told that I have cast iron baseboards on a venturi system. It's a two-story house with only 1 zone the kitchen has the cast iron radiator that's is not getting hot. I have Bleed the system and I have water coming out of the bleeder the only time I can get the radiator hot is when I'm bleeding the system and letting the water drain out. One side if the piping is hot but on the return side is cold. The radiator worked before the boiler was replaced. Am I missing something? When I bleed the system no air comes out only water and if I keep bleeding the radiator I do get hot water but it won't stay hot and gets cold.



I will upload pics

Comments

  • JStar
    JStar Member Posts: 2,752
    Boiler

    Could be a stubborn air bubble caught in the venturi tees.



    The circulator placement on a diverter-tee system is critical (in fact, it's always critical). It should be on the supply, after the expansion tank.
  • rpezz50
    rpezz50 Member Posts: 13
    ?

    Ok not sure what I am looking for is it a valve? Is in in any of the pics I sent?
  • JStar
    JStar Member Posts: 2,752
    Heat

    The venturi tees are pictured in the 2nd photo. They need to be spaced at least the same width apart as the width of the radiator. Is this so?



    Also, check to make sure that the radiator valve is completely open.
  • rpezz50
    rpezz50 Member Posts: 13
    Ok

    They are the same width and the valve are all fully open. It did work before the boiler was replace. Anything else I can do?
  • New boiler, new problem

    Have you called the installer of your new boiler? Maybe he should be solving this problem.

    When you have a new boiler installed, you should expect the system to work!--NBC
  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669
    edited November 2013
    pump

    The pump must be on the supply header AND you need to install a bigger pump.

    A mono flow system needs a pump with a higher head ( at least 15 ft.) GPM must be at 10% of output BTU of the new boiler.

    That TACO 007 isn't gonna get it.

    That installation is a perfect example of selling a Cadillac but installing it like a YUGO.

    People shouldn't be able to buy high tech boilers and furnaces without going to factory class. I have 
  • rpezz50
    rpezz50 Member Posts: 13
    edited November 2013
    Pump

    You know I had thoughts that the pump was under size. Can you point me in the right direction for a bigger pump? Also I think that pump came with the boiler.
  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669
    edited November 2013
    pump

    The pump that comes with a boiler is not always the right pump for the system. The pump MUST be sized for the total combined load and monoflow systems are VERY restrictive to flow.

    There isn't a good pump that fits your needs. We need to know what your boiler is fired at.

    BUT the Taco 0014 or the Grundfos 26-99 FC on medium speed would be my best choice. I think the Grundfos is a better pump.

    You are not going to like the price.

    The company that installed the boiler should install the new pump on the supply line at no cost to you. This will teach them a lesson to do the job right next time.
  • RobG
    RobG Member Posts: 1,850
    Pump

    Also make sure that the new pump is installed correctly. As it is, the motor on the pump is vertical, it should be horizontal so that it does not overheat. The installer will need to rotate the flanges for the pump.

    RobG
  • another

    Another good boiler piped incorrectly... looks like a furance company did the job.. the pump is large enough for the whole system. A truely hydronic heating guy would know to just repipe the venturi fittings further apart to create pressure differratal to get the flow moving inside the raiditor.
  • another

    Another good boiler piped incorrectly... looks like a furance company did the job.. the pump is large enough for the whole system. A truely hydronic heating guy would know to just repipe the venturi fittings further apart to create pressure differratal to get the flow moving inside the raiditor.
  • rpezz50
    rpezz50 Member Posts: 13
    Install

    The odd part is that before the boiler was replaced all heating elements work and with the new boiler is pipe the same way the old one was.
  • was it?

    Was it same kind of pump?
  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669
    edited November 2013
    pump

    The pump is not big enough. A Taco 007 will not creat enough flow to make the monoflow tee's work.

    Spacing the tee's farther apart won't help much. The tee's create the pressure differential due to the venturi inside one of them. If you need more flow then you install two with the arrows in opposite directions. Installing a stronger pump WILL make the entire system work better. Also if this is an old cast iron system there should be a 100 grain strainer in the return pipe before the pump as it is installed now. 
  • nope

    Nope, that pump is big enough for that small system... I've had 3 speed pump set on nbr 2 on 7 pairs of mono flo, down feeding the cibb.. no plm.. its the space and fitting(s) make the the differeance.
  • Weezbo
    Weezbo Member Posts: 6,232
    wow .

    i wonder if you managed to see these boiler guys flushing the system prior to lashing the boiler to the monoflo loop?

    it always worked before makes me remember ....before What?

    i recently dialed in the field side of a mono flo system with new high heat commercial baseboard , and did some little bit of radiant slab off that , after i removed clumps and clogs and old pipe and fittings .where cutting the stuff out was the superior ticket.

    their system also got what i call booked bypasses , to keep temps more even and flow temps lower .the savings are huge . not too sure however by the end of this heating season ..the second one since the install i think it will have paid for my work and by next season ending the preponderance of the materials.

    the esbe valve with outdoor air sensor etc off the heat source is off the valve head and the oats missing mia so when i dial that mech room side in more than the install of a strap on temp control for the control off the coil injection to the monoflow and two new purge valves where by the field could be force purged and run through my pump with a caleffii dirt seperator ..., things should basically start working like they never did lol..

    when i got there the loop wass like 192 F and the supply side injector temps inn the 200's

    ..sorry i digressed , anyway, the flow is 32 gpm and the circ sized accordingly .

    rather than go to far afield , i am inclined to agree with the need the right flow rate Camp, and the Purge back purge and clean and add dirt separator rather than y strainer camps. even el cheapo tsp run through it will scour quite a bit of stuff out of the system ,

    so when it takes 100 psi blast of air ,{ ( Because my 60 psi purge/clean pump) to get the crappola out of a return line after three ,drain , purge back purge clean and purge do not prove flow through an emitter ... } then i am thinking things are not always what folks seem to recollect exactly.

    the return 90's to the emitters were clogged with what id call a tubular rock formmed to 90's and the 45's in the wall , so i am going to go with the camp that said , you hired them to make it go,

    get them back over there, too.

    *~//:)
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    When they come back

    Tell them you want the bx to the burner inside the jacket and a flexible oil line at the burner pump. The annual service guy is not going to be pleased at the difficulty of access and may just skip things. I can't see from here any other evils. The 007 is too lethargic.
  • rpezz50
    rpezz50 Member Posts: 13
    Pic

    Should this be leaking?
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    no

    And it is useless. Water flows right around the elbow. It was a feelgood effort to install. Close the cap and have it removed and plugged and the air elimination should be via a good air seperator at the boiler.
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