Radiant Heat problems

Tony_8

sounds like you have piping issues

tdim

radiant heat problems

I currently have a weil mclain boiler which heats 3 zones. For the last year now I have been having a problem where I'm getting little or no heat in 2 of the 3 zones. I have suspected several things as the cause. But due to not being all to familiar w/ the system I have not had much luck. Last year I replaced the expansion tank due to it starting to leak. I purchased the identical model and placed it in the same spot. Prior to 2 of the three zones where working w/ the 3rd getting little heat, that I suspected was the cause of the circulator pump having a problem. Also after replacing the expansion tank last year I was getting periodic discharge from the pressure relief valve on the boiler. This year prior to starting up the system. I went through the boiler manual and found under the troubleshooting section that the resaon for the discharge on the releif valve was either expansion tank not adjusted properly or pressure regulator valve being faulty. I knew the air in the expansion tank was correct, so I adjusted the pressure regulator valve and so far have not had any problems w/ the discharge. Although I am still having the problem w/ the 2 of 3 zones getting little or no heat. I have been all over the web to try and find something that may point me in the right direction, and have found nothing. The system consists of a weil mclain hydronic boiler with a Taco 007-E5 circulator pump for each zone. When I turn the thermostat on for 1 of the zones that gets no heat. You hear the relay kick on and the boiler start up. Once the water gets heated up and the boiler shuts down. The water does not seem to get to the zone. Is this a problem w/ the circulator pump? What is it that releases the water into that zone to cause the boiler to kick back on to heat the return water? Any help would be great. It has been quite frustrating!

[Deleted User]

Air

Sounds like you have air in those zones. Look for some bleeder screws on the base boards, open the screws and check to see if air comes out. Any air in the pipes will keep the water from circulating.

Steve Eayrs

Check the pumps in question..........

for proper voltage, and if they are circulating or not.
If the pumps are working, and you have air in the system as stated above, then you should be able to hear the pumps when running.
Steve

tdim

the system is a closed system w/ under floor radiant. So I do not have any bleeder valves. In the time being I had a heating company check the system and they told me that it is a mixing valve located right after the output for the 1st zone on the boiler. You don't want to know how much they want for that part and labor! regarding what the other person wrote in response to your solution. I do hear the pumps running when I turn the thermostat up. So the fact that there may be air in the system sounds more realistic than a real expensive mixing valve.

Tony_8

mixing valve

Does it serve all 3 zones or just one ? If it serves all 3 and you have heat in any of them, the mixer's not at fault. Is/are the circ(s) before or after the mixer ? Do the circs have IFC stickers on them ?

tdim

the circulators are located in the tubing going into the boiler. then the water comes out of the boiler which is where the 1st zone is located(which I receive heat in), as it travels up the piping next is the mixing valve, then it hits the 2nd zone, & 3rd zone. The circulator pumps are on the return piping prior to entering the boiler. the circs are taco 007 circs w/240F max.

Dave H_2

Mixing Valve(s)

First, has the system ever worked?

Second, is it my understanding that you do not have any mixing valves in the system or someone wanted to replace?

If you already do, you said the circs are on the return of the boiler. If that is the case, sounds like you have circ/mixing valve placement issues.

When working with radiant, the circ MUST always be placed after the mixing valve pumping towards your radiant floor tubing.