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Weil Mclain eco 155 stuck in standby

jtpfarm
jtpfarm Member Posts: 46
I have a 5 year old eco 155. It heats DHW all summer and everything else in the winter. Turned the heat on today and it won't start. It recognizes heat input but stays in standby. Target says 185 and supply 72. However, the DHW works just fine. 

Any ideas?
Thanks.

Comments

  • pedmec
    pedmec Member Posts: 938
    Most likely in warm weather shutdown. Whats the ambient temperature and whats the wwsd temperature set at.
  • hot_rod
    hot_rod Member Posts: 21,878
    needs to be a call for heat from the thermostat also
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • jtpfarm
    jtpfarm Member Posts: 46
    There is no outdoor sensor installed. There is a call for heat. It says "input: heating" when I turn on the thermostat. But it just stays in standby.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,600
    edited October 2022
    have you looked at page 90 of the manual that came with your ECO boiler? That is where. the troubleshooting section starts.

    If that is more that you want to do, then it is time for the professional service call. Ask the service company if they have a guarantee on the service work they do? If you don't like their answer, then call another service company.

    This problem may be as simple as a normal maintenance item (like the stuff that starts on page 98 of the manual) or it may involve replacement parts. Tell the company representative you don't want to pay for service that does not solve the problem. However you will gladly pay for quality repairs that do solve the problem.

    Don't be surprised if the repairs are a result of lack of maintenance items that have now become expensive to repair.

    If you don't have the manual, you can find it here https://www.weil-mclain.com/sites/default/files/field-file/550-142-122_0513.pdf
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • jtpfarm
    jtpfarm Member Posts: 46
    edited October 2022
    Yes. The troubleshooting section is pretty small and basic. Nothing related to what I have going on. 

    Professional service? What's that? Very few plumbers in this area. If you do finally get one to answer the phone or return a call, they don't want to do diagnostics or repairs. Just sell a new unit. 

    I'm not getting an error or lockout. It simply does nothing when heat is called for other than "heating" appearing on the input line. But as I said, the DHW works fine.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,600
    edited October 2022
    According to the manual, If the display reads "STANDBY" then there is no call for heat.

    To be sure that the call for heat problem is not within the boiler control, you can place a jumper on the red 6 pin plug at the #1 and #2 terminal location... Power up the boiler and see if the standby message goes off and the circulator pump starts.
    This is the first step in the process of elimination for your boiler
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • jtpfarm
    jtpfarm Member Posts: 46
    That's exactly what I tried. When I jump those wires, "heating" appears next to "input".  However, the display doesn't turn blue and it stays in standby. When I remove the jumper, "heating" goes away.

    Nothing has changed from last season. I checked all the controller settings and went through the diagnostics to look at the sensor readings. Everything appears to be where it should be. I'm beginning to suspect a failed computer board.
    kcopp
  • jtpfarm
    jtpfarm Member Posts: 46
    Maybe this will help explain. The first picture is without the jumper, second picture is with the jumper. 

    (The screen is blue because it just turned the unit on.)
  • hot_rod
    hot_rod Member Posts: 21,878
    is this the system up to pressure? My tube a pressure switch is open, although it should show a fault
    Do you gave surge protection on the boiler? If the board is bad and needs to be replaced, add some voltage protection

    Did you try tech support?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • pedmec
    pedmec Member Posts: 938
    Check all fuses on control board. Then i would recommend tech support at this point if they are all good.
  • jtpfarm
    jtpfarm Member Posts: 46
    I don't have pressure or water level sensors.

    A surge is actually what I am suspecting. We had an odd power outage this summer that dimmed the power down slowly and came back quickly.
  • jtpfarm
    jtpfarm Member Posts: 46
    I haven't tried tech support. Will they talk with non contractors?
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,600
    edited October 2022
    How long do you leave the jumper in place? The control may need some time to start the process.
    jtpfarm said:

    I haven't tried tech support. Will they talk with non contractors?

    Yes. If you tell them that you had a pro and they could not find the problem. Have a multimeter ready to test continuity, resistance, and voltage as needed. You sound like you understand what is going on and how to follow simple diagnostic instructions over the phone. You can usually purchase replacement parts from Supplyhouse.com if they recommend any part replacement.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • jtpfarm
    jtpfarm Member Posts: 46
    I left it in for at least 15 minutes while messing with it.

    I'll give them a call. I do understand how everything works for the most part. I installed it and the rest of the system. Thanks for the help.
    EdTheHeaterMan
  • flat_twin
    flat_twin Member Posts: 350
    Have you checked the history for errors? Have you power cycled the boiler? Verified transformer voltage? Someone already mentioned low voltage fuses. DHW is ok but no space heating, no pre purge ramp up or attempt to fire for space heating does sound like a control issue. Eco 110 owner here.
  • Mwil0331
    Mwil0331 Member Posts: 1
    Hey there @jtpfarm what was the solution to the issue? I have the same boiler and it is doing the exact same thing. Working fine for the DHW calls but will not go out of standby for the heat calls even though the heat calls are recognized on the control display. Looks exactly like the picture you posted above of your control unit display.