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    Hot Water Problems, indirect fired Amtrol Heater (21 Posts)

  • Chris Chris @ 11:03 PM
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    Hot Water Problems, indirect fired Amtrol Heater

    I bought my house in August of 09' I have a Amtrol Top feed 41 gallon indirect hot water maker. The guy who installed this orginally had 1" feeds/returns through a 1" Taco zone valve, & a 007 on the return, and the hot water was minimal at best.
    (I also found out that we have very hard water where we are, and I dont have the money to install a water softner, so scale builds up on the coils of the heater/sensor.)
    I moved the tank about 4' away from the boiler and installed a Taco 0010 (thought was a good idea at the time) and kept my piping 1". Up unitl 2 days ago a guy at my LSH said that it's pushing the water too fast though the coil and not geting any heat transfer, if any. So sold me a Grundfos 15-58FRC. I have it on medium right now, but i dont see any change with the hot water. My question is, does anyone know if the high setting on the Grundfos is the same GPM's as the Taco 0010? I couldn't find any pump curves for the Taco or Grundfos. Thanks

    Me.
  • Chris Chris @ 7:33 AM
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    Zone Control

    You make no mention of a zone control on your boiler that gives hot water priority over space heating. Your problem may not be heat transfer in the sense of flow but heat transfer because the zone cannot deliver the adequate btu's for recovery.

    What is the btu out-put of the boiler? Does this happen all the time or when heating zones are calling?
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Chris Chris @ 10:47 AM
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    Hot-Water-Problems-indirect-fired-Amtrol-Heater

    The heating output of the boiler is 129,000 BTU's. I do have a zone valve control which the DHW is switched to priority, but this does not happen when the heating zones are calling just the DHW.
  • Gordan Gordan @ 8:39 AM
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    Look, I'm not a pro or anything but...

    ..."water moving too fast for the BTUs to hop off" is an unfortunately all too common and just as hopelessly misguided notion. Too much flow could have other ill effects (erosion of piping, higher electrical consumption for the circulator) but it will NEVER reduce heat transfer - it can only increase it by increasing the average temperature of the coil (by reducing delta-T across it.) As long as the tank's heat exchanger can keep up with the full boiler output, though, one wouldn't expect to see any advantage as a result of increasing the flow.
    This post was edited by an admin on March 26, 2010 8:41 AM.
  • Big Ed Big Ed @ 8:50 AM
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    Dirty Coil

    Have you cleaned the tanks coil ? Minerals build up on the coil and act like an insulation on the heat transfer ...
    I have enough experience to know , that I dont know it all
  • Chris Chris @ 10:52 AM
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    Hot-Water-Problems-indirect-fired-Amtrol-Heater

    You are right big ed. I have taken the coils out of the TD-40, and cleaned them. They had a mineral build-up on them, not much, but enough to cause a problem. I also cleaned the sensor probe that goes into the tank, which i thought the sensor couldn't get a good reading because of the buildup. So i out everyhting back together, but still no change in the hot water. Good tip though!
  • Chris Chris @ 9:26 AM
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    BTU Output

    Gordon you state that as long as the heat exchanger can keep up with the boilers full output. At what time during the heating season would the tank see the boilers full output if no priority zoning? Zero. What if the full boiler output is only 60,000 btu's? What recovery would you expect to get? How about at 100,000 btu's?
    An Amtrol top-down TD7 1st hour ratings for above would be:

    -60,000 btus-   89gph at a 90 degree rise. At steady state with a 70 degree rise 104gph.
    -100,000 btu's- 170gph at a 90 degree rise. At steady state with a 70 degree rise 173gph.

    It is important to know the boiler out-put and heating system requirement when sizing an indirect.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
    This post was edited by an admin on March 26, 2010 9:33 AM.
  • Gordan Gordan @ 10:53 AM
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    We're not at odds here.

    Chris, I'm not commenting on anything other than the notion that overpumping can negatively affect heat transfer. As you state, there's a lot more to proper system design than that, but apparently this meme is so widespread that even Siegenthaler thought it worthwhile to write an article specifically for the purpose of debunking it.
  • Steamhead Steamhead @ 5:57 PM
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    "Meme"?

    Gordan, I have actually seen this happen. When I first got into this, my own system was over-pumped. That's why I wrote about it.

    Over-pumping mainly shows up in converted gravity systems which have very little internal resistance. There are several reasons why over-pumping affects this type of system, one common factor is that it causes short-circuiting in radiators and older boilers.

    I've also seen it in baseboard systems where the pump was just too big. Throttling the balancing valves on the loops actually increased the baseboards' output. The solution was a smaller pump, which also reduces electrical use somewhat.

    Siggy and others maintain, quite correctly, that proper design is most important. Much of their information, however, deals with designing new systems rather than what we find in the field. Out here you never know what you'll find- maybe that baseboard system that ran well with a Taco 007 now has a 0011 on it, because that's what the tech happened to have on the truck when the 007 quit. Hey, all those little pumps look alike >:(

    With a coil-type indirect, you might need a circ with a higher head capability than the usual. I know this is true with the A.O. Smith "Burkay" coil heaters used with storage tanks on commercial jobs. Check with the manufacturer to be sure.

    Chris, is the Taco valve on your indirect feed a zone valve or a flo-check? Since the loop has its own circ I don't see why it would need a zone valve, but a flo-check would be needed. Take a pic and post it here so we can be sure, or tell us what the model number is on the valve. Regardless, the circ must "Pump Away".
    "Reducing our country's energy consumption, one system at a time"

    Steam, Vapor & Hot-Water Heating Specialists

    Oil & Gas Burner Service

    Baltimore, MD (USA) and consulting anywhere.
    This post was edited by an admin on March 27, 2010 6:08 PM.
  • Chris Chris @ 11:37 AM
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    Hot-Water-Problems-indirect-fired-Amtrol-Heater

    The system orginally had a 007 circ on the return servicing 2 heating zones and DHW, on the return. (the domestic had a 1 Taco zone valve) I removed the zone valve and installed a Taco 0010 on the supply pumping through the supply. (the 0010 has a flo-check installed) As, i stated before, a guy at my LSH said the 0010 was simply too big for my Amtrol TD-40, so he sold me a Grundfos 15-58 FRC varable speed pump.So no more zone valve on the DHW, still have them on my heating system, and still have my 007 on the return of my boiler for my heating zones. Hope this helps!
  • Chris Chris @ 11:37 AM
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    Hot-Water-Problems-indirect-fired-Amtrol-Heater

    The system orginally had a 007 circ on the return servicing 2 heating zones and DHW, on the return. (the domestic had a 1 Taco zone valve) I removed the zone valve and installed a Taco 0010 on the supply pumping through the supply. (the 0010 has a flo-check installed) As, i stated before, a guy at my LSH said the 0010 was simply too big for my Amtrol TD-40, so he sold me a Grundfos 15-58 FRC varable speed pump.So no more zone valve on the DHW, still have them on my heating system, and still have my 007 on the return of my boiler for my heating zones. Hope this helps!
  • heatboy heatboy @ 12:04 PM
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    It's not too big....

    ....just the wrong selection.  The 0010 won't overcome the pressure drop of the HX, let alone the piping and boiler losses, when trying to get the 10 GPM through it.  The 0010 is a high GPM, low head pump.  The 15-58 on high speed won't either, but it does get closer than the 0010.

    I don't think you mentioned what your domestic hot water demands are (i.e., fill and dump tub or drive through shower, etc.)  Does the water start out warm and go cold? 
    heatboy

    The Radiant Whisperer


    "The laws of physics will outweigh the laws of ecomomics every time."
  • Steamhead Steamhead @ 3:51 PM
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    Amtrol

    says 5 GPM thru the coil is minimum.

    http://www.amtrol.com/pdf/9040-586 01_09 BoilerMate Indirect IO.pdf

    The 15-58 or Taco 00R 3-speed circs should be able to handle this.
    "Reducing our country's energy consumption, one system at a time"

    Steam, Vapor & Hot-Water Heating Specialists

    Oil & Gas Burner Service

    Baltimore, MD (USA) and consulting anywhere.
    This post was edited by an admin on March 28, 2010 3:54 PM.
  • Charlie from wmass Charlie from wmass @ 11:07 AM
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    In Gordon defense

    The boiler would be able to give its full attention to the indirect when the boiler is not being called to heat the home. SInce boilers are over sized even when sized well ( if youe boiler size is exact it is an amazing alignment of the stars) and we use thermostats unless you are using a mod con boiler it will not be running 24/7 to provide heat even on design days. I believe he is simply stating that if the heat exchanger is in condition to and of sufficient size to take all the heat thrown at it than it will take it. Your points concerning boiler siaze and the related recovery rate are also fully valid and is actually supported by what Gordy is saying. I am voting for the coil being crud covered and this is causing the issue but a miss place zone valve could also be doing the problem. Now all together now " Can't we all just get along?"
    Cost is what you spend , value is what you get.
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  • Big Ed Big Ed @ 11:26 AM
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    3/4" boiler taps

    I looked up the model , the unit only supplies 3/4" boiler taps ... Limited input , ... Not in favor of using zone valves on indirects either ....

    What is the temperature drop across the boiler supply lines... This would tell you if the coil is dirty ...
    I have enough experience to know , that I dont know it all
  • heatboy heatboy @ 11:34 AM
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    What is your boiler output?

    With a 0010 (or 007), I seriously doubt you could overpump the HX due to it's pressure drop.  At 6 GPM (60,000MBH @ 20° DT) the 0010 will just move enough water to over come the drop through the HX and piping, if you are using a standard boiler.  If you have 100 MBH and want the whole amount through the HX, the 0010 will not do the trick.

    Recovery rates quoted don't mean much if the boiler/piping/pumping aren't correct.

    The Taco ZV, if a 570 series, may take 2-3 minutes to open upon a call.  Not the ideal ZV for a DHW application.  15 to 20 gallons of hot water could be taken from the tank before the recovery process even begins.

    I should add that a 0011 would be the pump of choice at 10 GPM, but your heating system will probably have way too much pump then.  The contractor needs to to a good job of picking pieces to make any system work correctly or this is what happens.
    heatboy

    The Radiant Whisperer


    "The laws of physics will outweigh the laws of ecomomics every time."
    This post was edited by an admin on March 26, 2010 11:41 AM.
  • billtwocase billtwocase @ 5:38 PM
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    Amtrol

    First i would lose the Taco zone valve and make it a Honeywell. Next those, and most indirects like to be pump away.  1" is overkill here, 3/4", pump away, and get a zone valve that acts within seconds and not minutes.   peace
  • beauty beauty @ 4:21 PM
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    Homeowner

    We had a very serious "blowout" Boiler Mate Model WH7L7P S/N BM027751EZ - Thank God our children were not near the hugh crack when hot water blew out Sat 12-8-2012 - The rest of this is bleak - You are saying unless original Hm owners you will do nothing to the "life-Time-Warranty" - What kind of product are you supplying to Hm owners - We own this home 10yr "2003/4 - built in "97/98" - I will never recommend your product - We understand there is a "class action suit" (which we will proceed) - This Model should be on the recall list or at least offer restitution to your failed product - How can you honestly just do nothing - We contacted original installer - (they got same results from you) - We took pics of the damange to this Model and would be glad to submit to You and other potential home owners thinking of buying your product - I would appreciate a response
  • Chris Chris @ 4:45 PM
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    The Warranty

    Clearly states that it is to the original homeowner. Not the mfgs fault if the person you purchased the home from or your home inspector didn't make you aware of it.

    The warranty would only cover the tank if it was covered. You still would have been responsible for the labor.

    Pretty much a standard industry warranty. Heck some only give you 10yrs..
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • beauty beauty @ 4:21 PM
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    Homeowner

    We had a very serious "blowout" Boiler Mate Model WH7L7P S/N BM027751EZ - Thank God our children were not near the hugh crack when hot water blew out Sat 12-8-2012 - The rest of this is bleak - You are saying unless original Hm owners you will do nothing to the "life-Time-Warranty" - What kind of product are you supplying to Hm owners - We own this home 10yr "2003/4 - built in "97/98" - I will never recommend your product - We understand there is a "class action suit" (which we will proceed) - This Model should be on the recall list or at least offer restitution to your failed product - How can you honestly just do nothing - We contacted original installer - (they got same results from you) - We took pics of the damange to this Model and would be glad to submit to You and other potential home owners thinking of buying your product - I would appreciate a response
  • Jim Pompetti Jim Pompetti @ 7:38 PM
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    You can

    cut back on your flow. To see if thatts the problem , on the out-put side of the tank,close the ball valve 1/2 way ,that will reduce flow . if it works your over pumping . IF not your coils could be scalled up.If i remember correctly drain the tank , run the boiler to heat the coils (in the tank) then fill with cold water . That will cause the scale to drop off . Just to be sure give Amtrol a call .
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