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Radiant heat zone not letting water flow

I live in Michigan, it's cold here, cold enough that my water line to my outdoor spicket froze and burst.

My house has 4 zones.

I have a Slant Fin Galazy boiler

I've had my walkout basement zone freeze (so I thought) in the past

The basement zone valve motor went bad

Upon receiving parts, I installed the new motor and a kit to adapt the new motor allowing the motor to be replaced without breaking the water seal. So when replacing this I had to open the system.

Prior to replacing and after replacing the part, I've not been able to get water to flow through the basement zone (by normal means, using the manual switch, or using the house water feed).

I've tried closing all returns from all zones and opening the system at the return of the basement zone but the house supply won't push water through. It does through all the other zones. I know the valve lets water out because I can back flow through the valve if I open the return of the basement zone. I've applied gentle heat everywhere along the exterior walls with small space heaters. It's been roughly 25-29 out the last two days. I had the basement up to 75 the last two days.

Do you think the zone is frozen?

If it is frozen, do you have any recommendations for thawing?

If it is frozen, and I can't thaw it, should I close that zone and leave the drain valve in that zone open to relieve pressure until it warms up outside and can thaw?

Is there anything else that could prevent water from flowing through the zone?

This zone flows from the boiler like this:

__ ____ ____ ____ ____ ____

|_____| |_____| |_____| |_____| |_____|

1 2 3 4 5

1. baseboard on interior wall

2. baseboard on exterior walkout wall

3. baseboard on exterior walkout wall

4. baseboard on interior wall

5. baseboard on exterior non walkout wall


  • mjcromp
    mjcromp Member Posts: 57
    hard to say

    Hard to say if it's frozen. If you are sure the motor valve is installed correctly and there is a little flow through there it could be frozen. The backup of water could just be pressure coming back from a frozen point.

    What kind of motor valve do you have? brand/model

    There was an error rendering this rich post.

  • Hydro
    Hydro Member Posts: 20
    uponor zone valve

    Those uponor zone valves have an indicator on the motor, and if you tighten them down to much, they wont work , when you tighten them, there is a horizontal line on the motor, and when you tighten it too much, you will cause the indicator to travel past the line which is no good. Tighten them until the indicator is on the line. Did you only replace the motor or the whole valve? is the indicator moving? and do you have a zone control module servicing the valve? Are the lights on? you should have green top left, then yellow, with demand, and red when valve end switch makes. No green means no power, and don't forget to check the fuse on the ZCM.

    There was an error rendering this rich post.

  • mjcromp
    mjcromp Member Posts: 57
    Not Upinor from description

    Upinor valves don't have manual levers or require a kit.

    Also if you over-tighten one they will leak flow when closed

    There was an error rendering this rich post.

  • Michigan_Tony
    Michigan_Tony Member Posts: 3
    Could it be air lock, how do I fix?

    Thanks for the replies.  I heated the basement walls and basement using a salamander heater.  I don't think it's frozen.  I suspect an air lock, but I'm naive on the subject.

    my valves are like this:


    Since I replaced the control valve (the motor assembly and the conversion kit [a plate, oring, and ball on a spindle]) the system was opened at the driving end of the circuit. At that point, water dripped out from the pipe and was replaced by air. 

    Now when I try to drive water through it first encounters up to 15 feet of air in the pipe (the pipe goes up and then runs parallel to the next room which means all of that water could have drained out).  Can that 15 feet of air in the pipe be an issue?

    Can someone describe an air lock and tell me if the air lock can prevent the feed line from pushing water through a zone?  I've even tried putting a wet/dry vacuum on the drain side and pulling water out while pushing water in with the feed valve.
  • Gordy
    Gordy Member Posts: 9,546
    edited February 2014
    Power Purging

    Did you after opening the system?

    Is the zone valve oriented correctly?

    Yes air in the line would be an issue. This would cause the loop not to flow, or be air bound.

    You need to bump the pressure up with your water feed valve to about 25psi, and bleed the pipes.

    If your piping allows you to isolate the boiler you can power purge under higher pressure.
  • Michigan_Tony
    Michigan_Tony Member Posts: 3
    Fixed It

    It's fixed!

    Prior to now I never really thought of/understood the pressure tank.  I just thought the pressure of the water feed was the same as the pressure of the system and couldn't figure out why the pressure of the water feed couldn't push out any air.  After realizing the purpose of the bladder tank and seeing the pressure gauge I increased the pressure to 22psi and got water flowing again. 

    Thanks for the help.
  • Gordy
    Gordy Member Posts: 9,546
    Your system pressure

    Should only be about 12-15 psi. Bumping up the pressure was just to purge the line. If your pressure is to high you may pop the boilers relief valve which is 30psi.

    Is the bladder tank properly charged? To 12-15 psi?