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New Uni Match - I only have two wires for a feeder

Hi all, my first post to HeatingHelp. I live in an 1888 Folk Victorian that has single ended steam heat. I have a Burnham Independence Boiler, new in 2018 that was installed rather hap-hazardly. The installer used the old McDonnel & Miller 67 LWCO and Uni-Match. It has a small case nearby that acts as a reservior of sorts. Bear with me, I'm a great tech for many things but Steam Heat is not in my wheelhouse.

When we first moved in during the fall of 2018, we had the boiler flooding the basement on a regular basis. The issue was the switch for the LWCO sticking in what I'm guessing was the "Fill" position, as if the boiler was low on water. I will add the old Uni Match Fill valve has only two wires running to it, not three.

Our boiler tech, who's not that great, diagnosed the switch on the M&M 67 LWCO was bad so we replaced that. Things were good for a bit until the Uni-Match decided to act up, not filling. The tech messed with it, disconnected the fill altogether, stating the board was bad so we have been manually filling which is becoming a nuisance. What he had rigged at one point was the the two wires connected directly to the solenoid on the fill valve board so everytime the system wanted water, the small pump would run and the fill would run, eventually flooding the system and the basement floor. Thank god I have a sump pump.

When the float in the LWCO calls for water, it is commanding that little pump on the reservior to add water and at the same time, the two wires to the fill valve have 25VAC on them. The old fill valve was somehow only using two wires to function but our tech has them both disconnected right now and I never observed where they were landed to.

I have a new Uni-Match WFE-24V but none of the wiring schematics seem to jive with what I have. What I want to know is, can I use the 25VAC to run the solenoid through the board on the feeder, choosing the #2 selection, 60 second delay, then 60 second fill, five cycles total, stops when the system is satisfied? The feeder had W, N & H terminals. Will it work wired up with just the W & N? I suppose since the voltage is AC, polarity is not an issue?

I know I may have left out some information, the reason it uses water like nobody's business is this; some "Tech" or handyman installed a radiator in the master bedroom that was originally for a double-ended system. On the "Out" end at the top of the radiator, it has a honeywell adjustable temp thermostat of some sort and a tube pointing down that has enough clearance to put a small bucket under it. It's venting up to a gallon of steam/water in less than two days time. It also doesn't have a steam check or a place to put one like the other twelve radiators.

Sorry this is long winded but this is driving me insane, having to keep filling the damned thing. Any and all help will be appreciated.


    EBEBRATT-Ed Member Posts: 15,517

    Sorry to say but you have some serious issues. You HAVE to get that radiator problem fixed pronto. Adding fresh water to a boiler will kill it fast.

    Your 4 year old boiler has 10 years of ware and tear already.

    Adding water all the time....fresh water contains oxygen and oxygen eats boilers. You have to get that fixed.

    There is no sense talking about a feeder which will ruin your boiler until that is fixed.

    If the radiator can't be piped right for some reason disconnect it and cap the pipe
  • WMno57
    WMno57 Member Posts: 1,264
    Welcome fellow Hoosier. Agree with Ed. Oxygen in the makeup water is destroying both your boiler and it's supply and return pipes. There may be a boss 2/3 of the way up the side of your radiator that can be drilled and taped for a vent. Then, plug everything else that is letting condensate out. All condensate needs to return to the boiler.
    You can post pictures here of your radiator. We love pictures. Just cut and paste.
    I DIY.
  • Jamie Hall
    Jamie Hall Member Posts: 23,276
    All the above regarding the radiator.

    Now for the feeder. You say you have 24 VAC on the McDponnell-Miller 67? And do you have the Unimatch manual? If so, diagram 4 on page 4 of the manual is what you want. Dip switch position 2 should be on, and the others off.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • KC_Jones
    KC_Jones Member Posts: 5,737
    It's not just fixing the radiator, it's finding out why the water is even getting to that radiator. It shouldn't even be there in that quantity.

    It sounds like you have a lot of issues. Pictures of the boiler, piping, the radiators etc. and we could do a basic system evaluation for you, if you are interested.

    The feeder, seriously, is the absolute least of your worries.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    JUGHNE Member Posts: 11,060
    Many here do not have an auto water feeder, just add as needed....which should be seldom.

    The most important thing is that the low water cut off works....that it actually shuts off the burner when tested.

    Pictures, please.
  • Ray_Indiana
    Ray_Indiana Member Posts: 4
    Thanks all for the information, I'm in the process of finding a replacement radiator (Uh-huh!) and getting that improper radiator shut down. The stem for the cutoff valve doesn't turn, even though it seems newer than any other valve in the house. According to the church we bought our house off of, the records show it's been this way since they were deeded the house in 1965(!!!).

    Tomorrow (Saturday), when we can do without some heat for a bit, I'm going to give the cutoff valve another try and if that doesn't work, I'm going to remove the lock pin in the Honeywell T104A on the "exit?", side of the radiator and make is so I can turn the the thermostat to the "off" position. It only goes as low as Frost Protection right now. At least that might stop the steam/water loss through that outlet tube attached to the V110F valve threaded into the radiator and buy me some time to find a replacement.

    When I have good light, I'll take a few pics of the radiator in question and maybe somebody can identify it and tell me if it's safe to drill/tap. As I alluded to in my first post, this radiator has no boss for a hole to be tapped but seems to me I read where you could tap a hole for a Hoffman Steam Check in certain radiators.

    FYI, I'm looking for a 38" X 10" eight section Rococo style radiator to match what's in the house right now.
  • Ray_Indiana
    Ray_Indiana Member Posts: 4
    Follow-up; Actually I didn't state the existing radiator didn't have a boss to drill & tap. Sorry, it's 2:00 AM and I'm out of gas.

    Thanks again for your insight.
  • jhewings
    jhewings Member Posts: 139
    edited January 2022
    It is unlikely that replacing the radiator will help. Look at you pipes. If there is no return pipe for that radiator (it sounds like the other radiators are 2 pipe), then it may be possible to make that one functional as a single pipe radiator. Pictures of the radiator and one of the other radiators and the boiler would be helpful.
  • Ray_Indiana
    Ray_Indiana Member Posts: 4
    Sorry, couldn't get pics uploaded today - I guess is acting flakey. To clarify, the system is a single-ended system with the exception of the one radiator in question, the one that came from a double-ended steam or hot water in my master bedroom. I'll get some pics up tomorrow for you.