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Vaporstat pressure break causes Ecobee thermostat to lose power

lowballj
lowballj Member Posts: 15
edited December 2018 in Strictly Steam
There isn't really a question here more of an observation and general frustration vent.

I have a Honeywell Vaporstat L408J1009 and when it breaks on pressure (10oz), it cuts the power to all things wired up in my boiler room. This includes the boiler, the thermostat power line that runs upstairs to my Ecobee, my hot water heater, and I assume my LWCO.

Because of this, it takes over 10 minutes after the vaporstat unbreaks on diff for the Ecobee to come back online, figure out what comfort setting to use, sync with all the temp sensors and then call for heat.

Fun screenshot of ecobee system monitor attached showing all the power losses

My assumption is that things should be completely rewired to not do this. I'm going to deal with this as-is for a month and have the plumbing company take a look when they come to fix a troublesome radiator valve.

Any wiring advice would be much appreciated. There's a Taco switching relay in the mix as well. I'd love to tackle this myself but I'm no electrical expert, nor is there a simple way to search "how do i wire up all the steam boiler things specific to my setup"

/rant :s

Comments

  • KC_Jones
    KC_Jones Member Posts: 5,796
    The answer is in this thread going on now.

    https://forum.heatinghelp.com/discussion/168070/question-about-adding-c-wire-for-thermostat#latest
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    Erin Holohan Haskell
  • lowballj
    lowballj Member Posts: 15
    Thanks.
    To ensure I'm understanding correctly...
    Currently my Ecobee C wire is wired to the 24 V terminal on the Taco relay. That relay loses power when vaporstat breaks. I should create a relay coil from the R & C on the relay to the R and W terminals on boiler control center.
    My question is if the vaporstat breaks and cuts power to the boiler, how would that still have 24 v and a closed loop of power to the t-stat?
  • KC_Jones
    KC_Jones Member Posts: 5,796
    The vaporstat should be cutting the 24v circuit for the burner, the transformer is still fully powered. I do not know how your specific boiler is wired, but there are 2 suggested methods to fix the situation. Add a transformer and relay system, or rewire your system such that the thermostat is first in line, not last.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • Steamhead
    Steamhead Member Posts: 17,313
    What make and model is your boiler?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • lowballj
    lowballj Member Posts: 15
    Burnham V8 Model # KV84
    The relay on the front is an Argo AR822

    I'm looking at getting an 24v isolation relay but am still convinced that the 120v needs to be rewired as the Argo relay appears to be last in line. Once the vaporstat breaks, how could that possibly still have power for the t-stat, even with the isolation relay?
  • ratio
    ratio Member Posts: 3,774
    With an isolation relay, you can pick up the 24V control power for the stat anywhere, IIRC some have even used 24VAC plug-in wall warts.
  • lowballj
    lowballj Member Posts: 15
    Could I just wire up something like https://www.homedepot.com/p/Honeywell-24-Volt-Transformer-AT72D/202264717 before the 120v loop that contains LWCO, vaporstat, etc so I can guarantee power to the t-stat?
  • ratio
    ratio Member Posts: 3,774
    Exactly so.
  • lowballj
    lowballj Member Posts: 15
    Ok so then one wire off of that to relay board R and another to relay board C? T-stat is currently hooked to R W & C

  • ratio
    ratio Member Posts: 3,774
    R & W. C is the common, R is the 24V source, W is the call for heat.
  • lowballj
    lowballj Member Posts: 15
    Yeah so if this is just to power the Ecobee 24/7, wouldnt it be R & C for a constant loop?
  • ratio
    ratio Member Posts: 3,774
    Oh yah, to power the stat you want R & C. Sorry, for some reason I though you were asking about landing the W from the stat on the C, which wouldn't work very well at all!
  • zackwatt
    zackwatt Member Posts: 81
    I have a separate 24V transformer and ISO Relay for my Weil-Mclain boiler. It's wired up just as Ecobee recommends on their site.

    https://support.ecobee.com/hc/en-us/articles/227874667-Heat-only-2-wire-boiler-furnace-installations-for-ecobee-thermostats
  • lowballj
    lowballj Member Posts: 15
    Would something like https://www.supplyhouse.com/Honeywell-Aube-RC840T-120-120v-Relay-w-Built-In-24V-Transformer do the job?
  • ratio
    ratio Member Posts: 3,774
    No, that one's for line voltage. Try a RIB relay. Land the white/yellow with the stat C terminal, the white/blue on the stat W1 terminal, cap off the white/black & the blue, put the orange & yellow on the R & W terminals on the boiler. Take the constant 24VAC from the transformer you added to the stat R & C terminals.
  • lowballj
    lowballj Member Posts: 15
    @ratio I'm only looking for a constant 24v to keep the thermostat powered. Not sure how another relay would help
  • ratio
    ratio Member Posts: 3,774
    I assumed that you were looking for an interposing relay between the Ecobee and the boiler. The Aube relay you linked to is for controlling a line-voltage load via what amounts to dry contacts. While it has a common, it only puts out a few VA, not enough to power a WiFi enabled stat.

    Sorry for the confusion.

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