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Ultra 155 weil McCain boiler question

eugd
eugd Member Posts: 71
Well it’s been too good to be true that this boiler has worked all season with no issues Since the weather has got a little warmer but I still need heat them and the boiler is choosing to modulate hot water and prioritize boiler priority one (DHW) Most of the time instead of putting out he demand in the past it would module in some hot water and put out heat demand.  Also on the taco relay zone 1 which is usually on when the hot is called on doesn’t appear lit up but the boiler prioritizing and keeping Making hot water for her indirect tank.  And I noticed that the expansion tank needs to replaced because it’s full of water the issue?  The expansion tank should be here today I’m gonna replace it later tonight if it comes but I’m trying to figure out why I’m not getting heat prioritized when it’s needed as always thank you for all of your help and you could gentlemen have been a huge help in resolving many of my issues

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    Does anyone else have trouble with this post? Outside of needing a new expansion tank, I'm not sure what is being asked?

    "Since the weather has got a little warmer but I still need heat them and the boiler is choosing to modulate hot water and prioritize boiler priority one (DHW) Most of the time instead of putting out he demand in the past it would module in some hot water and put out heat demand."

    Maybe if this was 3 separate sentences?

    If the Weil-McLain Ultra 155 was connected correctly, the DHW circulatoer would not be connected to the Taco zone control. It would be connected to the DHW terminals on the WM Ultra. The call for DHW would be connected to the DHW connections on the WM Ultra.
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • HVACNUT
    HVACNUT Member Posts: 3,906
    If the zone for the heat is not lit up in the zone panel,  then follow the thermostat wire back to the thermostat or air handler, or wherever it goes. 
  • eugd
    eugd Member Posts: 71
    Sorry for me not being coherent.  The boiler keeps modulating for domestic hot water for the indirect water tank when it is not needed. And when heat is needed for the baseboards  or called by the thermostat the boiler makes DHW the priority rather than providing heat for the two zones.  In the past I noticed that when domestic hot water was being made zone 1 for the For the indirect tank with light up right now the boiler is making Hot water throughout the day without zone one lighting up and heat is not been consistently made or produced for zone two or three for the baseboards could this have anything to do with the expansion tank on the indirect water tank? What should I look other areas.  
  • eugd
    eugd Member Posts: 71
    I’ll follow the Thermostat wire from the boiler to the hot water tank and then from the hot water tank to the Taco Relay  and see if anything disconnected in the mean time.  
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    edited March 24
    Look at my next post below.

    I'm not sure what series of WM Ultra you have, and I'm not sure what Taco SR relay you have, But there is more than one way to connect the wiring. If connected incorrectly, that may be your issue. I have made the following diagram for you. Orange oval is where the Taco SR control should be connected. The X X Priority End Switch terminals should not be used. Only the X X Main End Switch should be used for all the room heat zones.

    The DHW thermostat should be connected to the WM Ultra as shown near the bottom of the diagram. the Red ovals show where the DHW circulator and the DHW Tank thermostat should go. not in the Taco SR control for DHW at all



    I hope this helps.

    Mr.Ed

    PS
    Depending on the WM Ultra series your control may be programmable. The wiring I suggested is for the "Factory Default" setting for the circulator and thermostat connections.
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
    eugd
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    edited March 24
    I have had this happen before. Do you have the type of water heater with the thermostat on top of the tank? Sometimes the well, where the thermostat sets, get filled with water. This causes the DHW thermostat to be permanently stuck ON. Disconnect the wire to the DHW thermostat (it has a plug that you can pull out)

    If that solves your problem, all you need is a new DHW thermostat. You may also need a new tank if you can't find where the water is coming from.
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
    eugd
  • eugd
    eugd Member Posts: 71
    Will double check everything.  The tank came so I’ll put it in later.    It’s a ultra 155 series 2 boiler that’s been a pain ever since it was installed.  
  • bucksnort
    bucksnort Member Posts: 109
    You have 2 issues that are unrelated. One is a pressure issue with the expansion tank. The other is electrical.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    edited March 25
    Check to see if the DHW thermostat is stuck ON. Check if the wires are crossed or connected. Check to see if the DHW thermostat is wet from being in the water as I mentioned above. This is easy to do by removing the thermostat control wire from the DHW tank. you can disconnect it at the Taco SR or at the boiler The best way is to disconnect at the #3 and #4 terminal on the boiler wiring connection shown in the following diagram Where I show the Blue thermostat wire connections.


    this illustration is where the #3 & #4 terminals are located on the boiler. Just behind the intake and vent pipes

    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    edited March 25
    Just a follow up.  I double checked everything wire wise and changed the tank.  I did not see and cross touching but think it could be the setting.  I have the boiler priority 1 set at for my DHW 130 (because my wife works in a hospital and for the extra germ killing when washing her scrubs)
    and boiler priority 2 set between (180-130). Could this be the problem? 

    I attached the pic or the manual setting 
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    edited March 25
    The Taco SR control is much like the WMCR controller. It does not have some of the terminals that the TACO has.

    What make and model of water heater do you have?
    Did you do the test I described above? The test is to remove the wires from terminal #3 & #4 on the Ultra 155 just behind the vent and intake pipe connection.
    What happened when you disconnect the wires?
    Did the boiler switch to heating the other zones?

    Can you post pictures of the boiler and piping that connects the boiler to the water tank?
    Photo from ceiling to floor from at least 2 different position locations.

    Also pictures of the wires inside the Taco control


    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    When I removed the wires I did it with the power off to the boiler.   I didn’t want to short anything.  Should I of did it with the power on?  I’ll post the pics of the Piping and wiring in the taco relay 
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    You need to put the power back on with the #3 & #4 wire off to see if the boiler will heat the other Zones. and stop heating the DHW zone. After you check that, then let me know what happens.
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    When i took off 3 and 4 it showed this still called for heat even though it was not in use
  • eugd
    eugd Member Posts: 71

  • eugd
    eugd Member Posts: 71

  • eugd
    eugd Member Posts: 71
    Looks like there is nothing attached to the zone 1 on the taco valves instead it’s on the isolated end on the terminal 
  • eugd
    eugd Member Posts: 71
    edited March 25
    Looks like there is nothing attached to the zone 1 on the taco valves instead it’s on the isolated end on the terminal and it goes to p15.  
  • eugd
    eugd Member Posts: 71
    edited March 25
    I also noticed that the wires 3 and 4 were really in 4 and 5  spots on the p2 block. 
    When I put the wires in the 3 4 spots the pump For the interactive and work
  • eugd
    eugd Member Posts: 71
    edited March 26
    You need to put the power back on with the #3 & #4 wire off to see if the boiler will heat the other Zones. and stop heating the DHW zone. After you check that, then let me know what happens.
    When I did take off the wires I turned in the other zones and they appeared to go on via toca  valve and the pump opened.  But the DHW pump did not kick on.  It appeared that the wires are in the 4 and 5 spots not on the 3 and 4 spots. I movers them to 3 and 4 and the heating zones kicked on but not the DHW.  So I moved them back to 4 and 5 spot on the terminal for now 
  • eugd
    eugd Member Posts: 71
    The boiler is still constantly making hot water for the indirect tank even though it’s not called for?  
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    edited March 27
    DHW thermostat should be connected to 3 & 4 according to the manufacturer's wire diagram.

    Taco X X end switch (the brown wire in your picture) should be connected to 5 & 6 according to the manufacturer's wire diagram.

    If those wires are not the way the manufacturer diagram specifies, there may be a problem.
    here is the manufacturers diagram from your heater. see the RED lines I added? ... that is where the TACO end switch should go. Weil Mclain 5 & 6 go to X X on Taco



    The blue wires I added are where the indirect DHW thermostat wires go. DHW thermostat wires to Weil Mclain 3 & 4

    Here is a close up


    Do you know a good professional technician that can help you?

    Mr.Ed
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    Unfortunately I don’t.   Every guy I have over either not familiar with the unit and calls Weil mclain tech support or creates another problem.   The boiler worked for the last 2 years since with help for the forum figured out the the installed reverse wired the supply and return sensor.   I’ll try to look at the diagram tomorrow.   Thank you for your help
  • eugd
    eugd Member Posts: 71
    I realize that this wire coming off the indirect tank goes to the red terminal that is in the diagram above that Ed the heater man posted.  Where should it be relocated to.  On the diagram it said DHW should not be hooked up to the terminal. 4 and 5 on p11 terminal?  
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    There are 2 different controls for the Weil Mclain Ultra It depends on what series boiler you have I believe on the series 1 and series 2 the DHW thermostat gets connected to terminals 3 and 4 as shown here

    On Weil Mclain Ultra series 3 and 4, the DHW wire is connected to 4 and 5 as shown here.


    Do you know what control you have or what series you have?

    This is why I do not like Weil McLain boilers.. they are constantly changing their design. This is very confusing.

    Do you know a professional who can solve this? The questions you ask indicate that you are not understanding what I am trying to communicate. I am sorry for not making myself more accurate.

    Respectfully submitted

    Mr. Ed

    I am offline for the rest of the day. will return after 8PM
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    edited April 3
    I have a series 2 155 ultra boiler the controls module is the lower one. That looks like this one the DHW indirect tank is connected to the p11 4,5 terminals.  The p15 terminal has spots 1 and 2 connected to the taco switch isolated end switch connected.  I’m sorry I was looking at the other Schematic diagram and thought you were referring to P to wear the relays appear to be powered.  It appears that the boiler is wired correctly from what I understand    This problem only started recently since the temperature out side became warmer where the boiler modulates water over the demand in heat   Or at least I did not notice during this winter   There is  no external temperature sensor attached to the boiler   
  • eugd
    eugd Member Posts: 71
    I disconnected the 4 and 5 wires and the boiler was able to call for heat in the heating zones. And make heat  
    when I move the wires on the p11 terminal or spots 3 and 4 instead of 5 and 6 it does not turn on the circulator for the DHW.  Based on the diagram it shows the wires are in the correct and wired correctly.  Based on the diagram for the control part 511-330-267
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    Do I understand correctly? When the DHW thermostat is connected to 4 and 5 on P11 you do not get heat to modulate. Only the DHW circulator operates and the burner operates on high-fire. No heating for the zones.

    This happens even when you set the DHW thermostat below 80° and the water in the tank is over 120° you still have no heat but the burner continues to fire to high fire and the circulator to the DHW tank still operates.

    The only time the burner stops firing is when the water in the boiler is over 170° high limit but the DHW circulator continues to operate.

    I this correct?

    Then when you remove wires from 4 and 5 from P11 the heat will go to the Heating zones. and the burner will fire on a lower input (or smaller flame)

    Is this correct?

    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    edited April 4
    Do I understand correctly?  When the DHW thermostat is connected to 4 and 5 on P11 you do not get heat to modulate.  Only the DHW circulator operates and the burner operates on high-fire.  No heating for the zones.
     

    When the wires are removed I do get heat in both zones with baseboards.  The circulator for the DHW is not the priority.   The issue I been having is that The boiler does not prioritize the heating zones when called but will module hot water for the indirect tank.  Even though the thermostats and taco valve is calm for it.   I first thought it was air in the system but bleed all the zones and the boiler several times before posting. 


    The only time the burner stops firing is when the water in the boiler is over 170° high limit but the DHW circulator continues to operate.

    Yes the DHW is always bing modulated.  Even when no one is using it and the heating zones are off. Rather than the boiler going into stand by it’s working on making hot water before it was just go into stand by and rest.  


    Then when you remove wires from 4 and 5 from P11 the heat will go to the Heating zones. and the burner will fire on a lower input (or smaller flame)  
    Yes 


  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    edited April 4
    Your Weil Mclain Ultra appears to be operating the way it is designed. When there is a call for DHW the boiler stops making heat for the zones and will only operate for DHW.

    What this is telling me is that the wire from the DHW thermostat will not open. The Wire might be crossed or the insulation may have failed and the wires are making contact with each other. The other possibility is the DHW thermostat is defective and always closed. To determine if the wire is bad or the thermostat is bad, make sure the wires are connected to 4 and 5 on P11. then disconnect the wire at the DHW thermostat.



    Good night . I will look for your answer in the morning
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    Removed the wires and the boiler producing heat for zone 2 and 3 and the DHW turned off.  I check the continuity on the wires and no break in connect.  And wires not crossed 
    Probably the thermostat?  
  • eugd
    eugd Member Posts: 71
    edited April 4
    Removed the wires and the boiler producing heat for zone 2 and 3 and the DHW turned off.  I check the continuity on the wires and no break in connect.  And wires not crossed, the second the I reconnected the wires boiler to modulate hot water even through temp was already hot and it was off for less than 10 minutes 
    Probably the thermostat?  
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,078
    I thought you may have a bad DHW thermostat back on March 24.


    Sorry I could not communicate more clearly.

    Mr. Ed

    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • eugd
    eugd Member Posts: 71
    edited April 5
    Yes your right with your prediction.  No apologies necessary.   I’m so appreciate of your time and wisdom.   This forum has resolved a lingering issue two years ago because the installer wired it wrong and I didn’t have a problem until now.   I’ll tell you this boiler is a real Pain since I got it.  It’s moodier than my teenage daughter.   

  • eugd
    eugd Member Posts: 71
    I double checked to make sure it’s hooked up something Could’ve slipped up when I took the cover on and off they’re hooked up in both areas.  
    Maybe this also contributed to the problem of the hot water be modulated all the time? 

    On the indirect tank took the wires off and on the switch the switch has continuity, I put them back on the switch between the two terminals.  

    also I check the wire continuity they are no breaks The Wires  have continuity and resistance
    the wires are not crossed on the switches they are too short and on there respective terminals.  Also I added a romex connected and locknut to secure the wires better in the DHW thermostat box.  
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