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  1. #14
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,827
    I was reffering to testing each zone idividually.

    Although not 100% acturate, it works well when you can't see all of the loop, but its a very long proccess.(not a DIY thing)

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  2. #15
    Join Date
    Jan 2002
    Location
    New Hampshire
    Posts
    1,285

    I'm with Been

    Turn up all of the zones, run the boiler till the temperature stops rising (unless, of course, it's oversized), and see what the difference between the supply and return is. If it's near 20 F, you don't have a pump problem. Period.

    If it never stops climbing, and goes off on limit, the boiler is bigger than the load. The pump can't cure that.

    The pump never sees 400' of pipe. It only sees the longest single run. If any other zones open with shorter runs, it makes the head lower, as in less resistance, not higher.

    Use 6' of head for each hundred feet of piping and baseboard. You might have 7' of head (resistance) on that system, OR LESS, when other zones are open. You still have to move the water in the long zone, so you can't go any less.

    You won't get 12 GPM unless about 3 zones are open. Fawgettaboudit on one zone at a time.

    70' of 3/4 baseboard on a zone will cool the water 20. 35' will only cool it 10. If you don't have enough board to drop the water 20, but the boiler raises the temperature 20, the boiler will shut off on limit. That ain't a pump problem, it's a design problem.

    I'll quit now.....

    Noel

  3. #16
    Join Date
    May 2002
    Location
    Colorado
    Posts
    697
    Noel has given you some very good advice based upon tried and true rules of thumb. But he didn't mention the zone valve problem you seem to have.

    If you have insufficient flow -- particularly through the zone with three loops -- get rid of the Taco zone valves. They have a Cv of 7 and will cost you about 4 feet of head at 10 gpm and 6 feet of head at 12 gpm. The Tacos are better than Honeywell valves, which have a Cv of 3.5, but they still have too much flow resistance for multiple-loop use.

    The White Rodgers 1361-103 2-wire 1" zone valves have a Cv of 37 and won't noticably impede the flow. Full flow valves such as these should always be used to control multiple-loop zones.

    The Cv (Coefficient of Volume) of a device is the flow rate of water at 60 F that will result in a pressure drop of 1 PSI (2.3' of head) as it passes through the device.

  4. #17
    Join Date
    Sep 2002
    Posts
    3,708
    Thanks Panama..your post makes it clear that the concept
    of equilibrium hold true for mechanical energy on the pump side as well.


  5. #18
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,510
    the same question i asked in you last post about this same thing
    on a 25 degree day is the bolier shutting of on limit
    whith a 20ged delta t. if so is your house warm still or is it colder in the house. taco 007 is strong enough to handle your system from what you have given us. what is your reason for wanting a bigger pump installed
    call slant finn and get all the info on the bolier you need
    a bigger pump might be a mistake
    if you are concerned about lift change it to a taco008 it will give you if i remember correctly about 9 ft of lift at about 11 gpm. dont have anything in front of me but i think i am pretty close. if you do this get to just incase because very few techs carry them on thier trucks.

  6. #19
    Join Date
    Jan 2002
    Location
    New Hampshire
    Posts
    1,285

    lift?

    The number is 800 873 4346 at Slant/Fin tech service.

    Noel

  7. #20
    Join Date
    Jan 2005
    Posts
    152
    Noel says:
    Turn up all of the zones, run the boiler till the temperature stops rising (unless, of course, it's oversized), and see what the difference between the supply and return is. If it's near 20 F, you don't have a pump problem. Period.
    I'll do this. If my delta is lower or higher than 20degrees, what does that point to? Plus, I bet I'll find different deltas on different zones. I know for a fact that the amnt of fin-tube on each loop differs a bit.

    The assumption, is that the temp of the boiler will stop rising (before hitting 212degrees) if its properly sized? This is obviously done under close supervision.

    Thanks for helping with this. If a contractor can do something simple to stop these $300/month bills in the winter; that's great.

  8. #21
    Join Date
    May 2002
    Location
    Colorado
    Posts
    697
    Alex,

    If your main concern is your high heating bills, I suggest you look at the house first rather than at the heating system. How are your windows, wall insulation, attic insulation, and envelope leakage? Is your boiler in an enclosed space with adequate outside air ducts? (You don't want your boiler drawing heated air from inside the house because then you have to heat it twice.)

    If you can find someone in your area to perform a blower door test for $150 or less, have one done. They are almost always very revealing. You will be shocked where the air leaks are.

  9. #22
    Join Date
    Jan 2005
    Posts
    152
    Panama says:
    If your main concern is your high heating bills, I suggest you look at the house first rather than at the heating system. How are your windows, wall insulation, attic insulation, and envelope leakage? Is your boiler in an enclosed space with adequate outside air ducts?
    I'm concencentrating on the circ, becuase a Taco 110 was removed in 1999 as part of a boiler replacement, and an 007 was put in its place. I'm sure the people who spec'ed the 110 had a reason for doing so. I'm querying the experts here to see if a 007 is under-sized for my environment.

  10. #23
    Join Date
    Sep 2004
    Posts
    654
    The Taco 110 circ was original equipment on nearly every residental boiler I came across, then the 007 circ became the norm (1980?).

    IMO, changing the circulator (smaller or bigger or whatever siz) on a new boiler will not reduce your heating bill. That is a function of your house infiltration. Seal the windows and other air leaks and you'll save $$.


  11. #24
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,510
    alexb
    why is your bolier set at 212degrees that is way to high
    you are waisting a lot right there. the aveage temp on a bolier is between 180 and 195. some times it there is a shortage of base board it is raised to 200degrees so it might keep up. if for any reason your watter presure drops you can boil the water and have bigger problems.
    i dout you unit is to small or your pump is either
    find the leaks in your house and fix them. next turn down the water temp. next make sure you have enough combustion air near the unit. have the gas co. clock the meater to make sure the unit is useing the proper btu of heat.have next have your unit cleaned heatexchange burners and have the draft checked. next make sure the manifold presure is correct. all of this is what needs to be looked into be fore you waiust money on a pump. also have someone clean the base board fins. they will build up with dust and depree over the years and not give enough output. then make sure nothing is blocking the bottom of the base board and slowing the natural draft through it.
    if some rooms are hotter then others close the top lovers so the heat is more even. make sure the t stat is not being affected by only one room. stop all drafts.
    with all this done you should see a differance.
    i will bet most of your broblen is in the base board

  12. #25
    Join Date
    Jan 2005
    Posts
    152
    why is your bolier set at 212degrees that is way to high
    Mr. Murdoch said I should open up all zones & loops, and run the boiler until the temp stops rising. I'm guessing this means that with all zones/loops open, the heat loss thru the fins will equal the heat being introduce into the boiler, and the boiler temp will stop rising(?) Otherwise the boiler will keep rising until I hit 212. Measuring the Temp. Delta at the point the boiler temp stops rising should equal 20degrees of delta.

    My hi-limit is set at 180, and the temp guage on the boiler seems to read just below 190 when the burner shuts off.

  13. #26
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,827
    Keep in mind, that baseboard is rated at a 65 degree air temp, so if you do this test on a warm day it won't take long to reach high limit temp.
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