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Excuse the lack of knowledge...is this a 3-way mixing valve?

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Gilby, Oct 26, 2012.

  1. Gilby

    Gilby Member

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    Is the emergency gravity flow overheat loop a necessity? i feel like that's something I could use - especially since at the moment my pumps have a mind of their own. Would that just allow any excess heat to be free'd up in my garage instead of the boiler continuing to heat if the furnace isn't calling?

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  2. Gilby

    Gilby Member

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    Bringing up this old post one more time.... I just spoke with a gentleman at new horizon. I had purchased a 3 way mixing valve - but as this post was about - my system already had one. I called to arragne a return....He was less than friendly on the phone and accused me of some things, but after some conversation, we came to realize that perhaps my boiler isn't actually plumbed wrong. Rather, my two pumps that are circulating to my furnaces are wired to the thermostats in the house. Meaning hot water is circulated to my furnaces only when the furnaces call for heat. He seemed to think this was a major issue and that those pumps need to be wired directly to the boiler and cirulating constantly. He also thought I may need a relay between the pumps and the controller to avoid the controller being overloaded and shutting off at inopportune times. It kind of makes sense, but thought I'd run it by all you guys as well. Let me know if that's a viable thought after our brief conversation.

  3. You do have a near boiler pump wired to the controller, right? In addition to the two zone pumps?

    If so that piping though poorly executed is the same basic design I am using without a problem...
  4. Where does the power for the two zone pumps come from? Is there some sort of relay or zone control between the house thermostats and the zone pumps?

    Wiring those pumps to run 24/7 might help eliminate some variables, but you should be able to have them run only when the house calls for heat once you get things figured out.
  5. Gilby

    Gilby Member

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    The near boiler pump is wired to the controller. The two zone pumps are wried to the thermostats in the house. They only run when the furnaces call for heat. The guy at New Horizon said they need to be wired to the controller and circulate constantly. I wasn't sure if this was a big deal or a not so big deal. He made it sound like a big deal. The boiler functions quite well when it's up to temp and running. The cold start has given me fits with those pumps. They'll shut off on their own for no reason and the boiler overheats. Was wondering if his advice of installing a relay to avoid overloading the controller was valid as well.
  6. It doesn't make sense to me that the zone pumps need to run 24/7. Sounds like something is getting lost in translation. That will just overheat your house. However they shouldn't be shutting off if the house is calling for heat.

    To rule out problems with the zone pumps you can temporarily wire them to run 24/7. Just take an old extension cord cut off the female end wire it to your pump ( disconnect the existing wire) And plug it into an outlet.

    You do need to have an overheat aquast that turns on at least one zone if the boiler starts to overheat if you don't have tem running 24/7

    The near boiler pump should be on whenever the boiler reaches 145. It should not shut off if the boiler fan does or for any other reason unless the boiler is below 140. If it is shutting off there is a problem with the rk2001 controller. ( the 140 - 145 setpoints can be changed) The near boiler pump may cycle on and off as the 3 way valve starts opening and allowing cold return water which cools the boiler below 140. This is normal.

    From a cold start it takes me about 30 minutes to get the entire system up to 180. A lot longer if i try to burn wood that has been seasoned for two years. I have set the near boiler pumps launch temp to 160 with an off temp of 145. This avoids the cycling.
    Taylor Sutherland likes this.
  7. Now that I think about it some more I think I understand what New Horizon was saying.

    Since you are using water to air exchangers the zone pumps can run constantly without overheating the house. Not ideal but it is simple to wire.

    Some question so I can understand your wiring a little better.

    - Where is 120v power for the pumps coming from?
    - Is the red light on the rk2001 controller on all the time? OR ONLY when the thermostats in the house are calling for heat?

    Also does the boiler fan shut off when the boiler reaches its setpoint?
  8. Gilby

    Gilby Member

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    He told me that the pumps need to circulate nonstop as long as the boiler is running. He says the water will still flow through the coils in my furnaces, but that the thermostats need only to be hooked to the fan. When the house calls for heat, the fans kick on and push air past my hot coils. If no call for heat, no fan = no heat in my house. As it stands now, there is no water circulating anywhere, until those fans turn on. That makes sense to me...just wasn't sure if it was necessary.

    The near boiler pump functions as it should. i have it set to 165 normally. As my boiler is heating up from a cold start, the water temp increases to the 165. When that pump kicks on, my water temp drops back down as the 'cold' water starts returning. This normally takes about 30 minutes for the boiler to get up to temp and maintain itself with NO load. From there, once I turn a furnace on, the boiler has a hard time keeping temp. A part of that is my wood for sure. Definitely not seasoned enough, but I'm working on that. Takes time!

    I have an aquastat that has never been installed. It's on the list of to-do's. Also going to rig a dump system in my garage for those over heating moments.
  9. Fred61

    Fred61 Minister of Fire

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    You could have your thermostat control the circulator and install a snap switch on youe W/A heat exchanger to start the blower. That way nothing but the boiler is running when there is no call for heat.
  10. Gilby

    Gilby Member

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    Loc:
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    where is the power coming from?? I'm not sure I'm following that one.

    The red light is on all the time.

    The fan shuts off when it gets to 175 or wherever I may have the dial set to.

    Like I said, the whole unit functions very well when it's up to temp and the house is up to temp. It's the cold start that is messing with my pumps for some reason. On Sunday we returned to the house from being gone. My boiler got upwards of 205-207 - I could not for the life of me get those pumps on and started to get nervous. The furnaces were both running, but only blowing cold air cause there was no water circulating to them. I usually can just slide the controller up or down and you'll hear them kick on. you'd think it's just a loose wire, but like I said, when it's all up to temp, those pumps have never failed. not sure why they only shut off on a cold start??
  11. I'm assuming the hOuse thermostats are low voltage. The circulator pumps use 120 volts. Somehow the low voltage thermostat is sending a signal to the zOne pumps to turn on. Usually this is done without the the rk2001 controller. So I am wondering how shaking the rk 2001 can have any effect on the zone pumps. Unless the rk2001 is the source of the 120 volts to the pumps.

    In the pics you posted there is conduit going from each zone pump to a junction box. What supplies power to that junction box?

    It sounds like the biggest problem is whatever is switching on those pumps is faulty. Usually a thermostat wire is connected to a relay of some sort to turn on those pumps. Such as a taco sr 501.

    http://www.pexsupply.com/pex/control/search/~SEARCH_STRING=Sr 503

    If the rk2001 is somehow trying to switch on those pumps that could be the source of your problems. From what I've read on here I don't think rk2001 is robust enough to handle switching three pumps.

    The simple answer is to wire those zone pumps to run 24/7 and leave the thermostats only controlling the furnace blower. If that fixes your problems then a you can upgrade your wiring so they don't run 24/7 with a snap switch and or zone controls. But one step at a time!

    You also want to wire in that aquastat in parallel with one of the thermostats to turn on the furnace blower if the boiler gets above 195-200 degrees. Until you do that make sure one the tstats is turned up really high whenever the boiler has a fire going.

    I wouldn't run the boiler again unless you are sure the pumps will turn on. The easiest way to do that is to plug them directly into the wall. Grundfos actually sells the pumps with a cord. But it's easy to wire one yourself.
  12. BoilerMan

    BoilerMan Minister of Fire

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    Just a thought, the RK2001's internal relay is only good for 400 watts. Just a few circulators. I installed an ice cube relay to run my whole system, so the RK2001 is isolated.

    TS

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