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Weil Mclain Problem

mjcromp
mjcromp Member Posts: 57
in THE MAIN WALL
OK WM Ultra80 Heat only no DHW. Boiler is not recognizing a call for heat. Even if I jump the TT's together or the DHW side I get no response from the boiler. No error codes, Fuses all good. Wiring seems to be fine. Again no error codes just sits there with 0 60 on the display and 60 is the temp in the lines. Pump comes on and fan just barely spins. does not try to start nothing. Boiler is set for 01 in heating and DHW Those who know know what that means. If your next line is to replace the Honeywell control board i'm right with you and been there done that. I'm about out of ideas here. Thanks

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Comments

  • CMadatMe
    CMadatMe Member Posts: 3,086
    edited November 2009
    What size

    boiler pump are you using? Can you take a pic of the boiler and piping and post? Jump out the flow switch and see if you get the boiler to fire.  Another quick question. Do you have the cover on the boiler when you are trying to fire? Had this happen to a contractor of mine. I didn't sell him the boiler but he called me and was trying to fire the boiler but it wouldn't fire. Found out you have to have the cover on the boiler or it wouldn't fire.

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  • mjcromp
    mjcromp Member Posts: 57
    flow switch?

    I don't recall seeing a flow switch in the boiler at all. Not in person or in the wiring diagram.

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  • CMadatMe
    CMadatMe Member Posts: 3,086
    They call it

    a supply/return temp sensor

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  • mjcromp
    mjcromp Member Posts: 57
    ?

    Seems kinda hard to jump a sensor when it's looking for a reading and when you disconnect it it show's an error code. I'm fairly proficient in fixing boilers as they are all pretty much the same basic concept.

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  • eluv8
    eluv8 Member Posts: 174
    No DHW

    After you jump the tt terminals there are a couple things to look for, power to the dhw pump, if no power check the settings on the boiler to see if DHW has somehow been disabled, if no power and setting is enabled then it could be a fuse, DHW settings could be of consideration as well if the control has been touched by unknowing hands. The manual will tell you how to do this. It can be different depending on the series you have. 
  • GerryE
    GerryE Member Posts: 3
    HVAC Product manager ( retired)

    Have you tried disconnecting the outdoor sensor.....if it has failed the unit will not fire. Removing it will allow the unit to fire up to limit if the sensor was bad!
  • mjcromp
    mjcromp Member Posts: 57
    Talked with

    Weil Mclain today and they mentioned it's a fan. We will see when it comes in. Thanks

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  • eluv8
    eluv8 Member Posts: 174
    confused

    Maybe I misread your post, I understood that the boiler is operating in Heating mode just not DHW. If the boiler runs fine in heating I highly doubt its the fan they work or they dont, however if you do not have heat or DHW the fan on an ultra would not surprise me. simplest method I know to quickly check the fan is to disconnect one of the cables to the fan, you will have to try one and then the other unless somebody chimes in and can describe which one for you and perhaps a better description of the test, after the cable has been disconnected the fan should ramp up if not chances are its bad. Do not let the fan ramp up for long, remove the wire just long enough to conduct the test and then clip it back on.
  • Unknown
    Unknown
    confused

    I think what he meant was the boiler is heating only,,, no indirect attached.
  • eluv8
    eluv8 Member Posts: 174
    Thanks Dave

    Yep, as I read it over its pretty clear. Some days I should really slow down and pay more attention.
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