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Circ pump stopped running continuously

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tmlhcx
tmlhcx Member Posts: 5
Hello all!
i have a l8148e with a circ pump that has been wired to run continuously for its whole life. My zone end switches have never been connected. I am fine with this. Recently my circulator pump changed behaviour to only running when the boiler fires. I have a l6006c aquastat wired to t tv.
What can i check to return circ pump to running continuously?
thanks a bunch

one water circuit in garage is unzoned and connects to a hydronic serpentine coil heater with a fan so water always can flow through it. Upstairs has one zone valve downstairs has one zone valve

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  • Derheatmeister
    Derheatmeister Member Posts: 1,549
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    What kind of circulating pump does the system have?
    tmlhcx
  • tmlhcx
    tmlhcx Member Posts: 5
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    Grundfos 15-58fc
    it operates when the boiler fires
  • Jamie Hall
    Jamie Hall Member Posts: 23,439
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    Well... it obviously gets its power from somewhere. Best thing to do is find out where -- and why that power source now responds to the boiler and didn't before. Any chance that there was a duplicate power source wired in from somewhere else that was always on -- but isn't now?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    DerheatmeisterEdTheHeaterMantmlhcx
  • tmlhcx
    tmlhcx Member Posts: 5
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    Thanks Jamie, ive tried not to change any wiring yet
  • tmlhcx
    tmlhcx Member Posts: 5
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  • Derheatmeister
    Derheatmeister Member Posts: 1,549
    edited September 2023
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    Not sure why the system was wired up this way ? Operating a 15/58 circ is the equavalent of leaving a 70 w bulb on all the time and as our parents have told us " Turn that light off when you do not need it" (Wasting energy) This Circ operating 100% would use Approx 18.420 watts over 30 years which is a couple Thousand Dollars.
    Personally i would remove the aquastat,Install a Zonevalve for the garage and wire the endswitches from the Zonevalves to the TT on the Boiler (8148)...This way the circ will only operate when there is a call for heat.
    tmlhcx
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,094
    edited September 2023
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    tmlhcx said:

    Hello all!
    i have a l8148e with a circ pump that has been wired to run continuously for its whole life. My zone end switches have never been connected. I am fine with this. Recently my circulator pump changed behaviour to only running when the boiler fires. I have a l6006c aquastat wired to t tv.
    What can i check to return circ pump to running continuously?
    thanks a bunch

    one water circuit in garage is unzoned and connects to a hydronic serpentine coil heater with a fan so water always can flow through it. Upstairs has one zone valve downstairs has one zone valve

    tmlhcx said:

    Grundfos 15-58fc
    it operates when the boiler fires


    These two comments contradict "circ pump that has been wired to run continuously for its whole life". and "operates when the boiler fires"

    Do you mean to say that "The boiler fired and the circulator operate constantly?"
    Do you mean to say that "The boiler fired as a result of the L6006 Aquastsat and the circulator operated constantly?"
    Do you mean to say that "a room thermostat fires the boiler as needed and the circulator operates constantly?"

    If 1 & 2 are the case, then what keeps the garage from overheating, because the circulator will put hot water into the garage heater with the circulator pump on constant operation? With your limited description of your system, and the recent change in operation, with no apparent change in wiring, I find no logic in your query.

    By looking at the wiring and reading your description of events, I might make this observation. At some early point in the lifetime of the system, the cover on the L8148E was placed on the control with a wire partially depressing the actual plastic relay contact actuator. This could make the contacts for the circulator pump engage resulting in constant pump operation by accident. When the T & TV terminals would get a call for heat, the plastic contact actuator of the relay would fully engage and operate the burners. When the call for heat was satisfied at the T & TV on the L8148E, the actuator might release the burner contact but the partially depressed contact actuator would keep the circulator contacts engaged, resulting in constant circulator operation.

    Just a Wild A$$ Guess.



    After a closer look at that photo, the black wire to the circulator (gray dash) is also close enough to the actuator to make the circulator pump operate constantly.

    Again Just guessing. ...because the way that pump is wired to the control, it can only operate on a call for heat from T & TV on the aquastat under normal conditions. As a test of this theory, just pull up on the metal counter weight that is attached to the plastic contact actuator with no call for heat from the L6006 and observe the pump and burner operation.

    Another thing I just thought of. more likely. What if the L6006 was set at say 190°F and the L8148 aquastat was set at 180°F. That would make the boiler operate as described because the L6006 will never get satisfied because the L8148 will not let the boiler temperature get to 190°F. But the burner will cycle on the 180°F limit.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    MikeAmanntmlhcx
  • hot_rod
    hot_rod Member Posts: 22,258
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    Better yet install an Alpha 15-58 it will start and modulates as zone valves open, draws under 40w at full speed, 7 w when idled. Your system will never be over pumped as it is now with a fixed speed pump
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    SuperTechtmlhcx
  • 109A_5
    109A_5 Member Posts: 1,387
    edited September 2023
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    Hello @tmlhcx,

    As @EdTheHeaterMan mentioned but from a different point of view, could these wires when the cover is installed with the curved corners be limiting the movement of the armature of the relay ? The cover is pushing on the Left most white wire, which is pushing on the Black wire then the Black wire pushing slightly on the relay armature, so it can't move freely. Not fond of the wire management near that relay. Camera angle makes it hard to tell if it is an issue.

    It does look like there are wires connected to the circulatior terminals in the Aquastat so constant circulatior running seems odd.

    I would wire up the system correctly (End Switches, is there a thermostat for both zones valve zones ?) and spend the money not wasted on worn out circulators and electricity on something you would rather have. I suppose with no zone valve for the garage it minimizes the pipes freezing and the fan only runs when greater heat is needed in the garage, however I could see the fan running when the boiler is not fired depending on the control and wiring sophistication.




    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    tmlhcx
  • Derheatmeister
    Derheatmeister Member Posts: 1,549
    edited September 2023
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    hot_rod said:

    Better yet install an Alpha 15-58 it will start and modulates as zone valves open, draws under 40w at full speed, 7 w when idled. Your system will never be over pumped as it is now with a fixed speed pump

    The Garage has no zonevalve... A Alpha 15-58 Circ will be running all the time :/
    tmlhcx
  • hot_rod
    hot_rod Member Posts: 22,258
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    the garage gets flow the time? Heats whenever any other zone calls?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    tmlhcx
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,094
    edited September 2023
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    I believe the original installer wanted to maintain 125° or 130° all the time since the T and TV are wired to the L6006. The constant circulator operation was not wired that way, but was a consequence of something else, because the circulator pump is wired to C1 on the L8148E. That wire to the circ. requires a call of heat on the T & TV of the L8148E for power to the circ..

    I also believe that there may have been times that the homeowner may have experienced some "Not Enough Heat" conditions over the years during extreme cold weather. That is because the highest temperature the boiler can get is what the L6006 is set to. There is no proof of a garage thermostat in what has been posted so far, but if there is a garage thermostat (perhaps Line Voltage) that could keep the fan from operating and causing garage overheating.

    What a waste of fuel and comfort. It would be so easy to do it correctly and make the boiler a "Cold Start" as it was designed. That would let the boiler temperature get higher during the colder months and would let the burner stop operating when there is no call for heat resulting in fuel savings.

    But to answer the original query.
    "What can i check to return circ pump to running continuously?"
    There is nothing you can check because the circulator pump appears to be wired to the L8148E correctly from the factory and the
    "i have a l8148e with a circ pump that has been wired to run continuously for its whole life."
    is false unless something else happened like @Jamie Hall's duplicate power source or my crushed wire on the Contact Actuator theory.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    tmlhcx
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,094
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    What I would do in your situation @tmlhcx, is to make some minor wiring changes. Here is what you probably have now. With the limited information from your comments I believe it is close


    This is what I would change to make the system more efficient and offer more comfort for both the garage and the rest of the home during the colder weather. You will be amazed at the difference in fuel use and comfort.



    If there is no garage thermostat, then get one (1.) and wire it to the Switching relay (2.) like a Taco SR501 or a R845A relay in order to bring on the burners and the circulator when you need garage heat. Move the L6006 aquastat to the return pipe on the garage heater (3.) The fan will operate whenever the L6006 senses heat in the pipe going to the garage heater. The R845A relay to the garage heat to stop the garage from overheating. Wire to the low voltage the the switching terminals of the R845A to the T & TV of the L8148E (4.) and the red wires from the zoe valves to the T and TV on the L8148e (5.) This is the least amount of work and you dont need to drain the system to install a zone valve to the garage.

    This is not the best way to do this but it is the least amount of work and you will be 95% there.

    To get the best operation from your system you will need to add a zone valve to the garage piping which requires draining the system. If you are interested in installing another zone valve, I can give you that wiring diagram.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    tmlhcxMikeAmann
  • tmlhcx
    tmlhcx Member Posts: 5
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    You are all very kind giving me more info and advice, i will study it closely. I spent a bunch of time staring at the unit and wiring diagrams Saturday and am feeling “more” educated. 

    Ed you were right about;

    “”Another thing I just thought of. more likely. What if the L6006 was set at say 190°F and the L8148 aquastat was set at 180°F. That would make the boiler operate as described because the L6006 will never get satisfied because the L8148 will not let the boiler temperature get to 190°F. But the burner will cycle on the 180°F limit””

    I turned the l6006 back up which since wired to t tv it “calls for heat” but is indeed never satisfied and the l8148 manages itself and the boiler fires on and off within whatever the l8148 limits are. Circ pump runs continuoisly, yay!

    Ill take the week off from this and confirm systems operation. But everyones advice is good and even though garage heater fan is controlled by thermostat it is always warmer than needed in there during the summer, but not as bad as you think, im in alaska. 

    Before posting here i had already studied wiring diagrams for normal zone operation which is why i was so confused with mine not being hooked up etc. ill review all the helpful responses and make a plan. 

    Me my wife and dogs appreciate you all, but i especially appreciate helping me learn. If i rewire ill post an update
    cheers,

    —happy 3rd year first-time homeowner Tim
    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,094
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    Alaska or Arkansas or even Arizona, having a boiler maintain a minimum temperature of 160° or 180° will waste fuel. No need to keep the boiler hot if there is no call for heat.

    Take time to look at my second diagram. It is not that hard to do if you take each circuit one at a time. By circuit, I mean the end switch circuits (Red wires to T - TV). Then the Taco SR501 or R845A switching relay to operate the fan on the unit heater. Then the 3 and 4 to operate the T - TV on the L8148. That means there will be three wires connected to terminal 3 and three wires connected to terminal 4 on the switching relay. But that also means that there must be a call for heat in order to turn on the burners and circulator.

    THIS WILL SAVE FUEL. AS MUCH AS 10% or more. Enough to pay for the switching relay

    I try to make the diagrams easy to follow. Send me a private message if you have more questions.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    MikeAmann