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    How water boiler system (9 Posts)

  • Ringo311 Ringo311 @ 12:49 PM
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    How water boiler system

    I bought a Weil-Mclain Ulta 80 boiler and hot water tank system that was installed by a local heating company before last winter and we have experienced several issues. I live in western ny where it can be near zero temperatures for a couple weeks during winter. When it gets this cold the boiler will not heat the house to the thermostat temperature. It drops several degrees and will never 'catch up'. At times when it falls behind, it feels like there is a ton of heat coming out of our baseboards and at other times very little. This seems strange to me. If it warms up 10-15 degrees outside the house will get back up to normal temperature.

    The boiler has been efficient as heck but we replaced a 30 year old boiler that would send out some serious heat. We replaced the windows the same year as the boiler but it still seems cooler in our house on very cold nights than when we had the old boiler and thin and inefficient windows.
    Any suggestions?
    PS: When the boiler was first installed the whole house was getting scalding hot water (even the cold water lines were warm) so they first replaced the temperature gague on the water tank and then the whole water tank. We get inconsistent water temperatures at times - typically on colder nights (my hw lines are insulated and not very long).
    This post was edited by an admin on February 15, 2013 12:55 PM.
  • Tim McElwain Tim McElwain @ 1:07 PM
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    Was a heat loss done

    on your hose before the boiler install? What was the input of the old system as far as BTU's? There is a possibility the boiler is now undersized. This will typically show up at lower outside temperatures. Did the installer tell you what kind of return temperatures you would get on the new boiler in order for condensing to take place? What is the temperature of the water typically leaving the boiler?

    It could also be the case that the boiler control system was not set up correctly. I believe you would have the "U" Control on that boiler? Ask your installer some of these questions.
    This post was edited by an admin on February 15, 2013 1:08 PM.
  • Ringo311 Ringo311 @ 1:30 PM
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    -

    - I insulated the water lines since getting the new boiler. 
    - I believe the old boiler was 100k BTU. They said they did a heat loss calc but they did not do a proper one.
    - There are two loops (upstairs and downstairs) and they are both 100 ft I would say. They are sent out at 190 degrees F and return at low 180's typically.
    And one other thing: they vented the 3" PVC exhaust pipe to the outside but did not extend the 3" PVC intake pipe to the outside. It sucks air out of my basement. My basement is not finished and is pretty drafty to start.
    - I will talk to the installer now that I'm getting a better idea.
    Thanks!
  • Jean-David Beyer Jean-David Beyer @ 2:15 PM
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    I [also] bought a Weil-Mclain Ultra 80 boiler and hot water tank system that was installed by a local heating company

    I also used to live in Western NY (Buffalo, and then Kenmore), so I have some idea what it is like to live there. Fortunately, I do not live there any more. Two houses were heated by hot air (one forced hot air), one by hot water, one by a gas heating stove in one of the rooms, and one by one-pipe steam. they all produced enough heat, though the steam produced way too much. I tried turning down the valve, part way (I did not understand steam in those days) and the super did not like that I did that. Mainly the valve started leaking a lot of water.

    "When it gets this cold the boiler will not heat the house to the
    thermostat temperature. It drops several degrees and will never 'catch
    up'. At times when it falls behind, it feels like there is a ton of heat
    coming out of our baseboards and at other times very little. This seems
    strange to me. If it warms up 10-15 degrees outside the house will get
    back up to normal temperature."

    Was a heat loss done by the local heating company? It might be that your boiler is the wrong size, but your other complaints lead me to think the boiler was perhaps installed incorrectly, wired incorrectly, or programmed incorrectly.

    "When it gets this cold " How cold? What was the design temperature used in sizing the boiler? For Buffalo, you would probably use 6F; for Rochester, 5F.

    "it feels like there is a ton of heat
    coming out of our baseboards and at other times very little." Sounds as though the reset curves are incorrect, or the outdoor reset is not even connected. Also, possibly the sensors on the supply and return may be in the wrong place or hooked up backwards. The installer did pipe it primary-secondary, I hope (as required by the installation manual).

    " When the boiler was first installed the whole house was getting scalding hot water (even the cold water lines were warm)"

    Something seriously wrong there. Was the thermostat in the indirect hot water tank set right? On mine, there is a Line they suggest using at first. That one is WAY TOO HOT unless you have an automatic temperature mixing valve at the output of the indirect. It really sounds as though your system is either wired wrong or programmed wrong. Did the contractor even open the installation manual?
  • Ringo311 Ringo311 @ 5:40 PM
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    Mos

    They didn't do a heat loss. Not a proper one. They did a half-assed one which entailed looking at the size of the old boiler, asking me the SF of the house and maybe counting the doors and windows.

    Not sure what the design temp is. When it gets to 10F or lower the boiler starts falling behind.

    Outdoor reset is def not connected (see below). Not sure about the reset curves because not sure what they are - ill have to look into that. I believe the sensors are correct. Primary /secondary referring to type hearing system and water tank or the boiler loops?

    Since the water tank was replaced (after a couple weeks) we haven't had the scalding hot water but the temps have been inconsistent. This is the second time I've researched these issues. I read over the manual and found many shortcuts taken. I was told things like the boiler works better without the outdoor reset and that I didn't need an outside air intake. I was also told the Weil McLain rep supported installing it that way.

    Should I consider contacting someone from Weil McLain to look at the install? I'm planning on adding a radiant heat loop so I really want to make sure this is working right first. If its undersized I'm in a bad way.
    This post was edited by an admin on February 16, 2013 5:43 PM.
  • Jean-David Beyer Jean-David Beyer @ 9:49 AM
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    boiler works better without the outdoor reset...

    "I was told things like the boiler works better without the outdoor reset and that I didn't need an outside air intake. I was also told the Weil McLain rep supported installing it that way."

    You were told wrong. My FORMER contractor, the one that installed mine, also told me that, which is one of the reasons they are my FORMER contractor. But they are crazy. The only time it would work the same with and without, is if they installed a seriously oversized boiler when it would reset all the way down even on design day.

    Also, you not only need the outdoor intake, but the intake and exhaust need to be pretty close to one another (as specified in the installation manual) so that even with wind blowing across them, the pressure drop between one and the other should be low. If one is inside the house and the other outside, this will not work right.

    I bet the W-M rep did not say that. W-M do not go to the expense of writing and printing those installation manuals for the fun of it. They want their boilers to work right for many reasons. They understand their boilers better than some service contractors, such as yours, do.

    "Should I consider contacting someone from Weil McLain to look at the install? I'm planning on adding a radiant heat loop so I really want to make sure this is working right first. If its undersized I'm in a bad way."

    You sure should. I do not know if W-M will send a rep to a private individual, but they sure will when a contractor asks them to. At least in central New Jersey. I think your problems are much worse than an undersized boiler (if yours is even undersized). It sounds as though it is plumbed incorrectly, wired incorrectly, and programmed incorrectly. And the circulators may be too big.

    But do not take my word for it: I am just a homeowner, but I have almost memorized the installation manual, and read both the second and third editions of John Siegenthaler's hydronic heating book.
  • unclejohn unclejohn @ 10:42 PM
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    What Type

    Of pump is on the boiler? If it has a speed selector set it on the lowest speed. It it doesn't and you have a shut of valve on the outlet of the pump or anywhere after the pump not before it throttle it down until you get at least a 20* f delta t. In other words supply water 190*f return water 170*f.
  • heatpro02920 heatpro02920 @ 11:57 PM
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    Baseboard?

    If you have 100ft of base on each zone and when both zones are running you return temps are only 10* less than your supply temp, there is something wrong... Are all of your baseboard vents wide open? Is the baseboard installed a little bit off of the floor? no new carpeting blocking the bottom of the emitters? Are all of the boards getting hot?

    I would imagine if the base board is indeed set correctly and there are no air bound split loops, the problem is your boiler is undersized, this means that on your cold days your house sheds more BTU's than your system produces... BUT since your return temps are so high it is making me think this isn't the case at all....

    Does the burner run constantly on these cold days?

    Look into getting some Delta T circulators either bumble bees or something similar like 007-vdtf5...
  • tom3holer tom3holer @ 8:48 PM
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    Had a similar problem

    Have you checked to see if its short cycling? I had a new boiler installed and had the same issue where the baseboards would seem quite warm at times then much cooler at other times. It turned out that the boiler was short cycling, comming on them off. This makes the average water temp much lower than needed on a cold day. Check to see if indeed this is the problem. If so there are ways to help.

    Tom
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