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Weil Mclain Series 1 Controls Upgrade

Hi everyone,
Homeowner here with an approx 25 yo W.M. Ultra 230 Series 1. In the past I've been able to do basic repairs and maint - blower replacement, heat exchanger cleaning and cover replacement, igniter replacement, etc. But last February the u-control module went out and there are no direct replacements. To make it through the winter, I used the DHW outputs and then manually turned the boiler on and off with the main switch.
So now I have the 383-500-665 Controls Upgrade Kit to install.
But step #1 is to record all the setup data and Priority 1-3 settings.
This may be simple for you guys, but I'm lost! I see the words "settings" and parameters" used seemingly interchangeably, and then not.
My house uses this for radiant heating only. No DHW and not zoned.
Can anyone explain how to document all the settings that I'll need when I install the new control module?
I've attached a picture of the settings page recommended in the instructions manual.


  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,970
    edited October 2022
    You will need to record the previous readings only if you have a previous control. Since you do not have operating previous control, you will need to start from scratch as if the boiler is new. The setup instructions are usually very detailed and comprehensive to cover many different uses of that boiler. You will need to follow the set up instructions in the installation manual for a boiler that came with that control.

    The setup of the U control starts on page on 59 of this manual https://www.weil-mclain.com/sites/default/files/field-file/ultra-series-3-manual_1.pdf
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
  • ScottSecor
    ScottSecor Member Posts: 642
    Not much to add, but I looked up your CP number. Your boiler was built on 05/21/2003 according to Weil McLain.
  • 5thingsatonce
    5thingsatonce Member Posts: 4
    Thanks guys!
    @EdTheHeaterMan Can I ask for a clarification? We bought the house in July of '04 with this boiler in place. It's been great ever since. Last year only a part of the control - the part that kicked on the circulator pump, went out. I switched the leads over to the DHW outputs just to run the pump. Of course that meant the system ran full on which is why I had to shut it down when the house got hot. It still works that way, but I don't want to go through the whole season doing that.
    So I can power it on and go through the menu. I just can't figure out which settings and where they are.
    Is it possible those settings are still there? If so, how can I see them?
    Thanks again for your help.
    EBEBRATT-Ed Member Posts: 13,141

    you would have to have the instructions to the original control to access that information
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,970
    edited October 2022
    This is the control supplement that was published after Weil Mclain had the control in place for a few years. Seem's that Honeywell didn't tell Weil McLain everything there was to know about that control when they purchased it for the original Ultra. So Weil Mclain needed to publish an update for the people who already had the boiler. When the series 2 came out the update was included it with the series 2 boiler along with the original I/O manual. https://www.weil-mclain.com/sites/default/files/field-file/ultra-series-2-control-supplement_1.pdf

    I also have an idea that is less complicated. What ever is connected to the control voltage terminals 5 and 6* (where the room thermostat is supposed to go) can be connected to 3 and 4 where the DHW thermostat is supposed to go. That will get you automatic control of the circulator on the boiler as it is wired presently.

    The difference is that you will not have the benefit of the outdoor reset feature. So you gain automatic thermostat control but loose some efficiency.

    * I said "whatever is connected" because the thermostat is the usual control connected there, however you could power the boiler by way of a zone control relay or just an end switch from a zone valve. So whatever devise makes a connection from 5 to 6 will now make a connection from 3 and 4.
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
  • 5thingsatonce
    5thingsatonce Member Posts: 4
    Thank you both.
    Heaterman - thank you for the idea of using the DHW thermostat input. I'll try that first, although I've already purchased the rather expensive control upgrade, so I still have to figure out the whole complicated settings / parameters issue so I don't have to redo everything when I install the new control module.
    But for now, I just had rotator cuff surgery a week ago, and am having the other one done in December, so if that works as "an easy button" then I'll take it for now. I didn't anticipate how painful shoulder surgery would be.
    I'll let you know how that works out.
    Thanks again - I appreciate you guys taking the time to answer!
    HVACNUT Member Posts: 4,864
    Not sure about the Series 1, but with the newer revisions, if you replace the U-control, you also need to replace the display panel and reconfigure everything. 
  • 5thingsatonce
    5thingsatonce Member Posts: 4
    @HVACNUT Yes, the series 1 also requires replacing the display. Actually it's more like adding a display because the series 1 originally came with only a red, 4-place LED display. This wasn't clear at all until I found a series of videos on different topics that happened to feature a system where this upgrade had already been done. Here's a pic of someone else's upgrade in place.
    And yes, "everything" must be reconfigured. The instructions that come with the upgrade kit (which includes the new display) say to write down all these settings to configure the new control. Hence my original plea for help in how to find these in the original system before I take it apart.