help with in floor radiant heat

[newyorkjets]

Ill start from the beginning. I went to the customers house there was a leak on the return manifold. I tried to get replacement parts but was unable to... so i replaced the supply and return manifolds. Since doing so the floors dont get warm enough and the kick board heaters(2nd stage) are over heating. I cant seem to get any heat to the floors.

There are 3 zones two of which have 2nd stage kickboard heaters. The system isnt piped primary secondary like i would of liked, the supply and return run out from the boiler first tying into the first kickboard heater then the infloor radiant heat manifolds then to the last kickboard heater to complete the loop.

I have the infloor looped balanced at .75 gallon a minute according to the gauges on the supply manifold, the radiant mixing valve set to 120 degrees. The tubing is 1/2 inch pex



bad picture but gives you an idea of how its piped. What should the flow rate through the pex to get good heat transfer? Any info would be great thanks

[atmosphere]

I know that this is obvious..... Air??

[firecontrol]

Hydronics 101: flow & temp drop will tell you the btu's/hr you're delivering to the floor.
You said you balanced the flow to .75gpm with 120 input. Q = 500 x .75 x 20. 20 being the highest delta T a residential temp drop should be (IMO) Q = 7500 btu's/hr.
Now, if the .75 gpm was across the entire manifold, not much heat going out to the zone/hr when you figure it's across X amount of loops. If that was the flow on each loop that should be showing some warming in that zone.

[tim79]

You will need to remove the air that YOU put in the system

[Michael Nylund]

It´s not just the air You will have to remove. To do that You will have to control that You have the RIGHT static pressure (P0) in the vessel and the right Pa for the system.


Br // Michael

[Michael Nylund]

Sorry!
Wrong link.
Use this: <Removed link to your company>
Then download the animation that You find under "Documentation" - Mowies/training. // Michael

[Joehvac25]

If you haven't you need to purge it out. Loop by loop force the air out.

[beenthere]

Michael, you must be a Pro member to have a link to your company, and then it must be in your sig, not in the post body itself.

Please get your post count up to 15 and apply for pro membership, thank you.

[gsr kid]

stop and purge

[butternut]

If the problem is in the system (aside from air) I wouldn't be able to tell you for sure where to start because the drawing is pretty poor.
I can only assume what is where and by what I am assuming..... The loop isn't even built correctly. I'll assume I am mistaken but sorry, I cant deduce anything from this and this is what I do.

Just because it was working before you got there doesn't mean it was right before you got there.

[butternut]

Here is what it should look like if you want everything to work. Is this how it is put together?.

Cant find the option to delete a post so guess I am working on my post count now

[butternut]

Here is what it should look like if you want everything to work. Is this how it is put together?.
(opps!) in my haste to draw this out, I brought the kick heaters return in front of the mixing valve. That should be after the mixing valve toward the boiler. Adding a flow check between the kick heater and radiant return isn't a bad practice either.

[butternut]

Like this

[hvac69]

I dont see anything wrong with his system, maybe the drawing is rough and maybe missing some items but it has one main loop with one pump and 3 secondary loops with individual pumps.

[butternut]

I was thinking that there was one pump and then zone valves. If it is all pumps then it is still wrong although it isn't as bad as it would be with valves. The entire system can be run with one pump so having 4 doesn't make sense and if they were all circulators then there would only need to be three unless there was a re-circulation loop which there isn't due to the fact that there would be a mixing valve within the only possible loop.... which (again) makes me believe that it is one circulator an three zone valves.

I see that he put a circle as pump but he only designated one circle properly with the triangle within it. It's all so convoluted I just went to logic over stated.
If you are correct then I can see why at least one kick heater is getting smoked and the flooring is getting robbed.

[Joehvac25]

Like this

Should the kicks be mixed? Wouldn't they be high temp? Not saying just asking. If they are mixed why does the return have to be piped after the tee on mixing valve?

[butternut]

Here is the high side version.
Depends on your design, as to what you run. I dont like the blast furnace effect from kicks. When I do use them it's for cold spots, not area's. Toe heater is how I sell mine and that's all I expect from them.

[Michael Nylund]

Michael, you must be a Pro member to have a link to your company, and then it must be in your sig, not in the post body itself.

Please get your post count up to 15 and apply for pro membership, thank you.

Ok, if You say so. /
Micke

[Joehvac25]

Here is the high side version.
Depends on your design, as to what you run. I dont like the blast furnace effect from kicks. When I do use them it's for cold spots, not area's. Toe heater is how I sell mine and that's all I expect from them.

Ok makes sense