Hrydonic system help. I’m at a loss.

dirtman91386

Well guys I’m at a complete loss at what I’m doing wrong. I can’t maintain a .5gpm flow to keep my boiler lit. I’ve bled the system more times then I can count, not getting any more air out, removed the check valves on the pumps, opened all the lines all the way open, made sure my pump orientation and valve branch orientation are going to correct way. Any help on what I’m missing or doing wrong would be a small ray of hope before I trash this project with the biggest hammer I own. 

dirtman91386

hot_rod

Some creative piping there!
Looks like a tankless water heater, they typically need a high head circ.

Good news, with those fittings you can disassemble easily and pipe like this drawing, give it a try. You may still need more circulator on the heater loop.
One circulator does the boiler via the close tees, the other does the manifolds.

Ironman

Your piping and pump arrangement is wrong.

Also: is that an instantaneous water heater? If so, you’ve got the wrong appliance. It has way too much head (resistance to flow) to be used in a hydronic system.

You also are gonna have trouble with those Sharkbites allowing 02 diffusion.

And the pumps must be mounted vertical.

Zman

If you just want this thing to "work" repipe it as hot rod has suggested. You will need to swing the the circs so that the shaft is horizontal.
If you post the model number of the circ(s) and water heater, we can tell you if the circ sizing will work. The instruction manual for the water heater with resistance curve would help as well.

dirtman91386

So I mounted the circulation pump 90 degrees wrong?

edit. This is for my garage flooring. Also Your drawing looks the same to me as my pump routing. 1 pump feeding manifolds and 1 pump pushing the boiler right? 

hot_rod

Here is what is going on with your piping. Flow out of the heater via the upper pump, drown thru the two tees, thru the second pump and back to the heater.
There is no pump circulating to the manifold.

The drawing I posted above has one pump for the boiler, the second for the manifold.
Needs to pipe exactly like that. You're close, but not close enough.
The upper boiler pump may need to be sized larger, try and see, if the heater goes into lockout or doesn't keep up with the heat requirement that may need to be upsized.
The manufacturers don't always give you that pump requirement, because this is intended to be a water heater, not a boiler.
As a water heater, water pressure in the building drives flow thru the heater, you are depending on a small pump to do that. It may not.

dirtman91386

Its hard to see in the photo but It’s not 2 T’s. It’s a secondary loop purge T. zoom in on it. 

Water comes out of the heater to the pump then goes to the branch then to the hot side manifold returns through the cold side manifold then goes back to the branch valve then to the 2nd pump finally returning water to cold side of the heater. 

I have a flow right now of 2.2 gpm. There is an interior filter on the boiler that was pretty plugged debris. 

Ironman

Here’s how you’re now piped:

Ironman

Here’s how it should be:




Notice where the system circulator is. 

The way you have it, the circulators are in series, pumping only through the heater. Nothing will go to the system like that.

As hot_rod mentioned, you’re gonna need a much larger Circ pumping the heater due to its high resistance to flow. Either a Grundfos ups26-99 or a Taco 013 at least.

Ironman

Here’s a primary/secondary piping detail:


The flow is reversed in this diagram from yours, but it's conceptually the same.