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MM#67 and feeder compatibility

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kcopp
kcopp Member Posts: 4,663
in Strictly Steam

Current boiler is a Crown gas Steamer…

Not that old but it has a MM67 float type lwco.

The feeder is a Unimatch WF2-U-24

Customer complains that the feeder overfills each time lwco is triggered.

There are no settings on the feeder to limit the water.

VXT should allow more control correct?

Comments

  • JUGHNE
    JUGHNE Member Posts: 11,548

    Can you throttle the flow out of the feeder?

    I do that when the boiler feed pump is too aggressive and jiggles the float to shut off the burner. I use the iron quarter turn plug valves which I reclaimed from gas lines when replacing those with ball valves.

  • kcopp
    kcopp Member Posts: 4,663

    Tried that. No dice.

  • Big Ed_4
    Big Ed_4 Member Posts: 3,515

    I remember dip switches in the Unimatch where you set it for the 67 ..

    There was an error rendering this rich post.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 20,085

    Water level bouncing?

    I looked it up. Discontinued and replaced by a newer control.

    It is supposed to have a 3 position slide switch to change the timing.

    The newer control has something similar and also has different orifices to change the flow rate.

  • kcopp
    kcopp Member Posts: 4,663

    Im sure the orifices are LONG gone.

    That 67 switch is it. No delay or timing for cycle.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 12,041

    if you need better control the Unimatch WF2-U-24 can be replaced by a VXT. If throttling the water thru the Unimatch WF2-U-24 is not getting you where you need to be.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    kcopp
  • 109A_5
    109A_5 Member Posts: 3,898
    edited February 13
    image.png

    https://inspectapedia.com/heat/McDonnel-Miller-WF2-Water-Feeder-Instructions.pdf

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • kcopp
    kcopp Member Posts: 4,663

    Thanks. Confirms my thought that this "uni match" is not a good match for the system.

  • 109A_5
    109A_5 Member Posts: 3,898

    I would think with the correct orifice it would work great.

    The orifice with a VXT is about a Gallon a minute. If a Gallon a minute is too much a VXT may over fill the boiler too.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Big Ed_4
    Big Ed_4 Member Posts: 3,515

    Am I correct , if you throttle that unit down with the valve it sticks open ? I could be wrong but I think I tried that and found out ….

    There was an error rendering this rich post.

  • 109A_5
    109A_5 Member Posts: 3,898
    https://forum.heatinghelp.com/discussion/comment/1887871#Comment_1887871

    That may depend on where the manual valve is. The orifice is probably in the correct position for the solenoid valve to work correctly.

    Was the float functionality in the M&M 67 verified to work correctly ? The M&M 67's water level range of 'Call for Water' to 'I'm satisfied' should be very narrow. Sluggish float movement may mess up any water feeder causing it to over fill the boiler.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • kcopp
    kcopp Member Posts: 4,663

    Float works well.

    Its flushed often as the system is drained out when it overfills through the 67.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 20,085

    Do they have higher than normal water pressure?

  • 109A_5
    109A_5 Member Posts: 3,898

    @EBEBRATT-Ed I like where you are going with that but over 150 PSI, Wow !!!

    image.png

    I'd troubleshoot the issue until I understood what was causing the actual problem. Then determine the proper course of action for the repair.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 20,085

    @109A_5

    I learned long ago not to trust what the mfg. says 100%. I would not trust one of those to hold 100% at 150.

  • 109A_5
    109A_5 Member Posts: 3,898

    @EBEBRATT-Ed Yes I understand, for me it is a starting point reference.

    I'd troubleshoot the issue until I understood what was causing the actual problem. Then determine the proper course of action for the repair.

    Is the fill time for only 60 seconds, does the orifice actually exist… Understanding the actual cause of the problem makes for better repairs.

    Would have been nice if the manual gave more information about the actual orifice size and where it is so you don't have to take the whole thing apart it check it.

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • kcopp
    kcopp Member Posts: 4,663

    The water pressure is 60/70 psi.

    I have not started pulling the feeder apart but given that he has to dump water from the system Im sure they are missing.

  • 109A_5
    109A_5 Member Posts: 3,898

    Is this a new problem or has it been that way since the feeder was installed ?

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • kcopp
    kcopp Member Posts: 4,663

    Not sure.

    Im the 3rd guy in and he is not the original owner…

  • 109A_5
    109A_5 Member Posts: 3,898

    Looks like the orifice is on the outlet side of the solenoid valve. Thanks @Gordo

    McDonnell & Miller Uni-Match S-45 Valve Teardown. Water Feeder For Steam Boiler

    https://youtu.be/GD5QmoNLirU

    https://youtu.be/GD5QmoNLirU
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    kcopp
  • 109A_5
    109A_5 Member Posts: 3,898
    edited February 15

    Hydrolevel's VXT Service Kit #45-345 For Rebuilding Their Steam Boiler Water Feeder Valve

    https://youtu.be/gZc_wQgqhaI
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 20,085

    There is more than one uni match model. Not sure if the older ones had the orifices.

  • 109A_5
    109A_5 Member Posts: 3,898

    I believe I was using the orifice information from the correct manual (link posted above), from the model number provided. I'm assuming it is 24 VAC burner circuit unit. Maybe the orifice was removed or the valve leaks.

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System

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