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Main floor heat working fine, upstairs heat not so much

D818
D818 Member Posts: 17
Hi All - I have couple of diff zones for heating (gas furnace with both heat and a/c running through air ducts). The heat controlled by thermostat on main floor works fine, no issues. But the heating zones controlled by second floor thermostat is not working at all.

When the temperature drops below thermostat setting on second floor, it does not turn on the handler/call for heat. Nothing happens. Doesn't seem to be issue with handler as when i turn to "on" setting on thermostat it will kick on, just no hot air. When set to "auto" is when nothing happens.

I have changed the batteries in thermostat, no difference, and have changed the air filters recently. I think issue could have something to do with aquastat but I am not very familiar with how it works and hoping someone here might be able to point me in right direction. I'll post some pics below of my set up to hopefully give a better idea of where issue may be coming from (please note issue is with handler in attic where insulation is visible, other pics hopefully give you an idea of heat source/operation etc).



Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,453
    sounds like the problem is in the second floor thermostat or the damper(s) it controls or the wiring
  • D818
    D818 Member Posts: 17
    I think so too, Thanks Ed. Were you able to see pics?
  • D818
    D818 Member Posts: 17







  • D818
    D818 Member Posts: 17
    Hi All - I have couple of diff zones for heating (gas furnace with both heat and a/c running through air ducts). The heat controlled by thermostat on main floor works fine, no issues. But the heating zones controlled by second floor thermostat is not working at all.

    When the temperature drops below thermostat setting on second floor, it does not turn on the handler/call for heat. Nothing happens. Doesn't seem to be issue with handler as when i turn to "auto" setting on thermostat it will turn on, just not hot air.

    I have changed the batteries in thermostat, no difference, and have changed the air filters recently. I think issue could have something to do with aquastat but I am not very familiar with how it works and hoping someone here might be able to point me in right direction. I'll post some pics below of my set up to hopefully give a better idea of where issue may be coming from (please note issue is with handler in attic where insulation is visible, other pics hopefully give you an idea of heat source/operation etc).


  • D818
    D818 Member Posts: 17







  • Jamie Hall
    Jamie Hall Member Posts: 23,162
    Does the circulating pump for the upstairs zone run when you turn up the thermostat for that zone? That would be where I would start.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    D818
  • neilc
    neilc Member Posts: 2,689
    what's with the circulator all the way to the right?
    and why is it valved off?
    known to beat dead horses
  • mattmia2
    mattmia2 Member Posts: 9,572
    Does the coil get hot in the attic/the supply and return to it get hot at the boiler on a call for heat by the thermostat?
  • D818
    D818 Member Posts: 17
    The circulator all the way to the right is not connected to anything and hasn't been touched, not related. No heat supply at all in attic and handler is not started when thermostat reaches temp. Only turns on in "on" (not auto) and not hot hair.

    Good idea Jamie, the 2 circulators on the left in pic are labeled "HW" (assuming hor water) and "1st floor." I'm guessing the 3rd from left is for upstairs and will check that now after turning up thermostat. New homeowner here and not too familiar with installation but agreed thats a good start
  • mattmia2
    mattmia2 Member Posts: 9,572
    edited October 2022
    The blowerr in the air handler runs off that aquastat. the thermostat turns on the boiler and circulator, when the pipe gets hot the blower comes on. The problem is either the circulator or boiler isn't coming on or there is air in the coil or the piping keeping it from circulating.

    Try unscrewing the cap and opening the valve on the auto air vent in the attic and see if air comes out. Probably want to close it after it is circulating since there is probably a reason the valve was closed like the vent was leaking.

    That leaking auto air vent by the boiler should be replaced too.

    Also resideo is the name that honeywell just rebranded their stuff recently so that was replaced recently for some reason, possibly trying the wrong fix for your no heat problem.
    D818
  • D818
    D818 Member Posts: 17
    Thank you Matt, you are dialled in. I just turned up the thermostat on second floor then ran down to check boiler. Boiler kicked on but i did not feel pipe getting hot above circulator like i did when i tried testing first floor thermostat (turning up then running down to check). Boiler then gave a message saying "supply at set point - fan post purge" - I did not see any messages come up saying "circulator is on" either like i did with first floor test.

    Guessing circulator is the issue although it is tough to tell if shot other than whats described above.

    I just found that out about resideo today, thank you. And for leaky air vent are you referring to the piece to the left of circulator valves and below that looks a little rusty etc? I mentioned that piece to a tech last year and he said was fine but I will mention again and replace if needed, thks for pointing out.

    Lastly i think i already unscrewed cap in attic if you are referring to the white plastic piece all the way to left. Didn;t hear any air coming out and put right back on
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited October 2022
    I Installed that same type system in my home 30 years ago. Only difference is an oil fired boiler.
    @Jamie Hall is on the right track. There are several reasons the hot boiler water is not flowing past that zone's circulator. most common are"
    1. Defective circulator pump.
    2. No 120V current to the circulator pump (pump good, just no electric to it)
    3. Pump is operating however there is an air pocket in the piping from the pump up to the attic air handler's duct radiator.

    The second and third do no require parts to fix. For #3, see if there is at least 15 PSI water pressure in the boiler at the gauge in the basement. If there is low water pressure, then air can get into the pipes. That circulator pump can't pump AIR. Once you are sure there is enough water pressure to get the water up to the attic, then you want to let the air out of the duct radiator. I can't see how to do that in the pictures you have provided. There should be some type of air vent at the top of that duct radiator coil.

    The other problem (if it is not air) is to check if the pump is getting electricity when the thermostat is calling for heat. That is done with a meter for testing electrical voltage at the pump with the electric covers off and placing the meter probes on the bare wires. If you are not comfortable with electricity, then you need a professional to check that for you.

    #1 is a defective part. So there is no air and the pump is getting 120 volts power, but the pump does not run. Then replace the pump. I would check the free stuff first. A new pump won't fix the other two problems. So check them first
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    D818MikeAmann
  • D818
    D818 Member Posts: 17
    Thanks Ed, i checked the pressure and looks good (pic below). I also checked the electricity quickly with a touchless voltage tester when calling for heat. It's only up to 70 volts but goes off near circulator. The motor part seemsto be getting hot too but it hard to tell if ruthe nning properly. I did the screwdriver ear test on both first and second floor circulators and can clearly hear the 1st floor one moving, but don't hear that well for second floor pump although they are 2 different makes so hard to say. My best guess at this point with everyone's much appreciated help, is that motor might be stuck.

    I'm going to look at a little closer to see if i have tools for job but will shut off electric, close off valves, and remove the pump to inspect. Might be time to call in a pro but going to check. Thanks again




  • D818
    D818 Member Posts: 17
    Just to give an update - Issue was circulator pump. I replaced and now it's back up and running. Thanks again everyone
    MikeAmann