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Boiler won’t start while all seems fine ?? HELP PLS

docancho
docancho Member Posts: 38
I have a hot water heating with 3 separate zones.

I started up heat last night for heating season but boiler does not start. I checked that all circuit breakers are on, reset aquastat button is fine.

I see pilot light on, all thermostats are put on high and zone valves open.

I have replaced aquastat relay last winter.

I am not as knowledgeable so pls excuse my terminalogy, but it looks as aquastat relay does not get electricity to trigger boiler to start heating up water and pump.

Any insight is greatly appreciated.

Comments

  • Zman
    Zman Member Posts: 7,357
    What model boiler and controller?
    Re you able to check the 120 voltage to the boiler or the 24 volt out of the transformer.
    Every system is wired differently. Pictures would help...
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • docancho
    docancho Member Posts: 38
    Boiler is Weil-McLain (I am not sure of model) and controller is Honeywell Aquastat Relay L8148J.

    I am including only pictures I have - aquastat is on left side of boiler(in 1st picture).

    I was not able to check any voltage as I am not familiar with it.

    thank you!
  • Jamie Hall
    Jamie Hall Member Posts: 19,155
    If you really aren't that familiar with it... sorry to be a spoil sport, but the only thing that you can do safely is to check that the fuse or circuit breaker controlling the boiler circuit is OK, and that any emergency switches or control switches for it are turned on -- there may be more than one, such as at the head of the basement stairs etc.

    If that checks out, or you can't tell, may I respectfully suggest that you get a good boiler service person in!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    RobGKC_JonesZman
  • docancho
    docancho Member Posts: 38
    I did check circuit breaker and all seems fine.

    I left it ON this morning, and it came on for about 1 hr but something if off. water would heat up to max temp 180 set in aquastat relay and it would shut off normally but circulatory pump would only work while boiler is heating up water and then would stop

    isn't pump supposed to be working the whole time regardless of water temperature?

    my amateur thought would be that something is wrong with aquastat relay as it's not calling the pump to run.
  • Ironman
    Ironman Member Posts: 6,894
    If the boiler's getting hot, but the pipes are not, the it could be the circ or air binding in the system.
    The relay on the aquastat could be bad, but that's the least likely.
    I concur with Jamie that you need a service tech. There are proper tools and procedures for diagnosing everything and without the correct info you're just playing a guessing game.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • billtwocase
    billtwocase Member Posts: 2,385
    I would also recommend calling in a pro
  • rick in Alaska
    rick in Alaska Member Posts: 1,378
    I would almost bet on the aquastat being bad. I can't tell you how many bad ones I have seen which gives the same problem you are having. From what you are saying is happening, I would almost bet that the relay has a bad solder connection on the circuit board. There is just not enough solder on the connection. When the relay fires, it snaps hard, and after a while it breaks the weak solder connection , and then no burner!
    Simple check is to see if the relay snaps down when you turn it on. At that point you should have 120 volts to the burner. If you don't, and I am assuming the boiler is cold, then it is time for a new aquastat again.
    Unfortunately, just a bad manufacturing defect, in my opinion!
    Rick
  • rick in Alaska
    rick in Alaska Member Posts: 1,378
    oops. missed your 12:46 comment about it running. Could be same problem with aquastat though, but usually the burner just doesn't work.
    Rick
  • docancho
    docancho Member Posts: 38
    I brought it in an expert over the weekend and he determined it was a bad thermostat.

    he checked entire system with his voltage toll and said up to zone valves, all seems fine -- there's electricity/voltage. tested all options on aquastat relay and all worked when jumped.

    once he went to apts to test thermostat, one on top floor was not clicking (I had Honeywell manual) -- replaced it and said all is fine.

    1st day boiler worked fine. it's little warm now so it's not kicking in.
  • Ironman
    Ironman Member Posts: 6,894
    Thanks for letting us know how it turned out!

    Most OPs never follow up and let us know.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • billtwocase
    billtwocase Member Posts: 2,385
    Glad to see you are up and running again
  • unclejohn
    unclejohn Member Posts: 1,757
    edited October 2014
    Doesn't sound to me like all is fine. You said in your first post that all zone valves where open. Any zone should call for the boiler to operate, pump included. Jumping out the aqua stat is not the same as powering the aqua stat. When it fails again which will be soon, check to see if the boiler is hot by the temp. press. gauge. Also I can't see if you have a vent damper or not. One last thing was the control new or used.
  • icesailor
    icesailor Member Posts: 7,265
    I'm not the brightest bulb on the Christmas Tree. I spent years learning the application and functions or boiler controls. No one could "teach" me because no one really understood. SO, I'm self taught. To where some came to me for help with issues.

    You may be much smarter than I, or more experienced than I. but the whole integrated operation of boilers and controls is an extremely complex subject.

    It sounds like you just picked off a scab on an infection. The infection is still there.
  • docancho
    docancho Member Posts: 38
    you are absolutely right -- I usually focus on getting boiler up and running ASAP that I forget to ask basic logical questions.

    I am not electrician/boiler guy so would need to trust specialist that came that all is okay now.

    is it possible that boiler is controlled by only 1 thermostat on operation while each of 3 zone valves open/close by own thermostat? that's what it sounds to me like since once he replaced faulty thermostat, all went back to normal.

    I know vent damper is disconnected and manually open.
  • j a_2
    j a_2 Member Posts: 1,796
    I don’t think its a good idea to disconnect and jump out the vent dampener…Best to remove it and then install jumper….I know some manufactures want it done that way…..Unless your just doing it for troubleshooting and reconnect prior to leaving boiler operational….
  • SWEI
    SWEI Member Posts: 7,356
    docancho said:

    is it possible that boiler is controlled by only 1 thermostat on operation while each of 3 zone valves open/close by own thermostat? that's what it sounds to me like since once he replaced faulty thermostat, all went back to normal.

    Easy enough to test that hypothesis -- just turn down the replaced thermostat and turn up one of the others and see if the boiler fires to meed the call.