We have a new standard gas boiler in our home along with two thermostats, one for the basement and one for the rest of the house (living room, bedrooms, etc).

The problem we're having is that the basement has become the main thermostat and the upstairs thermostat doesn't even work. Whenever we raise the basement thermostat just a little, the upstairs gets extremely hot.

We wanted to know if we are able to have 2 separate heating zones with the same boiler so that the basement is able to have its own temperature while the upstairs can also be independent. We're not sure if we would need a different boiler to provide this kind of service or if it's possible to stay with the boiler we have to control the 2 separate zones in our home.

  • 1
    Are you saying that if you turn the upstairs thermostat all the way up it does not activate that zone and start providing heat? Possibly a bad zone control valve or circulation pump. The first place to start is diagnose why the upstairs thermostat is not working or resulting in heat. If you have two thermostats then (presumably) you have two zones on your current boiler. NEW boiler?
    – Alaska Man
    Apr 6, 2021 at 19:03
  • Yeah, the upstairs thermostat doesn't work at all, the basement thermostat is the only one that works and is controlling both the basement and upstairs. So if we set the basement to be 70 for example, upstairs would be a lot more than 70 and the upstairs thermostat can't control the upstairs temperature at all. The house had an old boiler so we recently replaced it.
    – Kayla
    Apr 6, 2021 at 19:08
  • 1
    You can have any number of zones but the boiler needs to be piped for those zones each with the proper valves and controls. Draw a diagram of the piping and show some and show some pictures.
    – d.george
    Apr 6, 2021 at 19:14
  • In theory the downstairs thermostat should not be controlling the upstairs zone if it has it's own thermostat. Sounds like a wiring mistake. You say new boiler, is the problem new with the new boiler, have you talked to the installer? "the basement has become the main thermostat" What does "has become" mean. To prevent this from being a guessing game, please provide as much info as you can in your question.
    – Alaska Man
    Apr 6, 2021 at 19:22
  • 2
    "the guy who was setting up the thermostats had just made the basement as the only working thermostat without installing the upstairs one." Clearly that is why it is working the way it is, because that is how it was set up. Have him come back and set it up the way you would like it. We don't know if you have two zones or anything about how your boiler is set up, see d.george's comment.
    – Alaska Man
    Apr 6, 2021 at 19:57

2 Answers 2


Yes, it can be done. It just needs to be plumbed (and wired) right. Each thermostat should control a valve that admits hot water to its section of the house.

The boiler should be wired to fire up whenever either thermostat is calling for heat.

For example, if the basement is cold, but the rest of the house is warm, then the valve allowing water to the basement should be opened, and the boiler turned on.


The answer is yes, you can. You could ask why your system isn't working that way. You could start by looking at whether it seems to generally be intended to work that way, in which case something is wrong.

If your system is meant to have two zones you should see the hot water pipe that comes out of the boiler split into two pipes, and each one should have a zone valve that will look something like this enter image description hereenter image description here

and, as you see in these pictures, each zone valve will have a wire attached to it that goes off to its respective thermostat. You can follow the wire from the zone valves as far as you can see them. If someone stands near the zone valves and someone else turns its thermostat all the way up or all the way down, you should immediately hear the valve open or close.

How far along that scenario is your boiler set up? You could add pictures to your question.

  • Some valves do take a short amount of time before they start moving. Mine seem like they need to build up a charge for ~1 minute then they start. Some may also blink when the are being activated which is helpful. Mar 12, 2022 at 21:28

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