Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

wiring baseboard heater to steam boiler

wilepine Member Posts: 2
First, I would like to say this site was very helpful in helping me get as far as I am on this project. I have a Well Mclain steam boiler that heats the entire house (2 floors). There is only one thermostat on the first floor that  controls the boiler. The basement is always cold so I added baseboard heaters. I followed the advise of the people here and ran the lines below the water level of the boiler. I have a bronze circulating pump, thermostat and SR501 relay. I know how to connect it all to make the boiler fire BUT what happens if the boiler starts to make steam for the two floors and the basement thermostat calls for heat and the pump turns on. Is that a problem? Do I need a zone controller if that would be a problem?

Thank you


  • Jamie Hall
    Jamie Hall Member Posts: 18,936
    edited June 2013
    Won't be a problem

    assuming that everything is piped correctly, that is.  What will happen, though, is that the circulator will be working with water which is pretty hot.  This might be a situation where, to avoid having near-boiling water in the pump you wanted the pump to be pumping towards the boiler at the end of the loop, rather than away from the boiler.  I'd have to really look at the pump characteristics to be sure.  That is, assuming that your loop is using boiler water direct.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • JStar
    JStar Member Posts: 2,752

    Install a bypass loop to temper return water into the circulator inlet.
  • Rod
    Rod Posts: 2,067
    HW Loop of Steam Boiler

    Hi- This article of Dan's might be of help to you.

    - Rod

  • wilepine
    wilepine Member Posts: 2

    Rod, the link was very helpful and JStar thanks for the input.  I will add a bypass loop.

    I have a SR501 relay, I do not want the boiler to fire with the connection in the basement. I just want heat there and the thermostat to control it. I know the heat will have to be ON on the first floor and that is the only thermostat I want to control the boiler. Is the SR501 the right relay foe the basement.? I see people talking about a Honeywell one.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,216
    If you place an aquastat

    in series with the relay to turn on the burner you can have it call for heat without creating steam.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
This discussion has been closed.