New Boiler keeps getting Air Bound. I think?

1RandoGuy_RandoProb

So I have a brand new Boiler and a brand new system. I did all the work myself even running the lines so I can provide as much information as needed. 
Not too long after getting it running for the winter I started having the problem of it getting Air Bound. At least I think that's the problem.
It runs perfectly for days and then one random day it'll make this weird noise, kind like a sputtering noise, or a low pitch clicking for about 5seconds. And then if you feel the pipes afterwards, there's no hot water flowing on the supply side or the return. And if I'm not paying attention it'll run endlessly but not heat the house and the temperature will drop, which definitely gets my attention. 
To get it going again is easy. I turn off the power to the boiler. I close the valves on the supply and return. I put a hose on the return side open it up slightly and since I have an auto fill I just let a little water in. I usually let a few gallons through. Try to match the temperature so that I know water has made it all the way through and hopefully pushed out any air. Then I open everything up turn it back on and boom, it works. I can get a couple weeks or even a month. 
I've tried all kinds of stuff. Repurging the system. Adjusting the speed on the pumps since they're in series. I've put cups out to see if I was getting the pressure relief valves opening. I took apart the pressure tank and refilled it. I've tried different operating pressures. I've tightened the motor housing down. I'm at my wits end. I'm really just trying to make it to summer so I can shut it down and work on it without the house getting cold.

Any Advice or ideas. Maybe even drastic ideas that I could do over the summer. 

fenkel

possibilty of a leak somewhere.. is the cap on the callefi air separator open a turn? have you purged the air out of the air seperater on top of boiler as well?

kcopp

It does not look like it is piped ideally. As far as I can see there is no Boiler/ Primary loop. Looks like you came right out of the boiler and right into the manifold. The boiler needs flow.
Especially w/ what it looks like radiant floor piping.
Yes it manual says its not necessary but it also says its preferred.

See page 18.
https://s3.amazonaws.com/idealusa.com/wp-content/uploads/2021/10/06170856/2019-28-Exalt-WHB-Installation-Maintenance-Manual.pdf

HVACNUT

The method you used does not show an external pump. The P/S method does show an external pump. So you have 2 choices. Remove the existing pump or repipe P/S correctly. 

Derheatmeister

Is the system installed in such a way that the system side circ can still operate while the DHW is producing hot water with the boiler circ. (Not wired to the boilers control but controled by the ZCB ) ?
We would have:
1. Installed this in a Primary/Secondy piping or a Low loss header arrangement.
2. Have a Auto delta p/delta t cir on the system side (Hindsights you could install and adjust a bypass valve)
3. Have the boilers control supply power to the circs.
4. Installed the fill valve in such a way that the gauge is visal without a neck injury
5. Installed a service valve that has a drain on the expansion tank for proper maintenance.
6. Any relief equipment would have to be hard piped not using electrical conduit/PVC and within 6" of the floor as per our local codes in order to pass inspection
7. Installed a Codensate neutralizer in order to pass inspection ..Maybe you have one on the other side of the wall ?
8. Used PVC for the combustion air.
9. Adjusted the Boiler with a combustion analyzer. Maybe you did this?
10. Not installed the ZCB in a place were fluid can drip on it and short it out.
11. Any wires would have to be restrained as per code in order to pass inspection.
12. Drip leg on the gasline ?
13. Rotated the 1" return manifold Ballvalve so that it is accessable
14. Restained the 3/4" lines
15. Installed the Manifold restraints on the return manifold.
As fenkel mentioned it could be a very small leak..
Based on the red flow indicators you may have also have some system fluid Maintenance requirements..
This Boiler was manufactured in 2020...Is this you first or second season?
Maybe...For now,start by closing the Auto air vents on the Manifolds but leaving the Discal vent open.
Hope this helps..

GGross

Combi boilers with an external pump must be piped primary secondary, when you call for DHW the valve in the boiler tries to move but your heating circ keeps running, stopping it from moving to the correct position. That is likely why turning everything off and back on fixes it, because you are resetting the diverter valve position. A re-pipe, per the manual is needed

hot_rod

Just 1 manifold?

Move the relay boxes under the receptacle. A p/s like this. If you want to do some manifold adjusting, supply into the left end, return from the right side by swapping the valve and air vent end caps
No need for the Discal to be up high, boiler has a high point vent. Dirtmag on return.

MikeL_2

   Is the red tubing connected to the multi - port manifolds rated for closed system heating? O2 barrier tubing?

1RandoGuy_RandoProb

GGross said:

Combi boilers with an external pump must be piped primary secondary, when you call for DHW the valve in the boiler tries to move but your heating circ keeps running, stopping it from moving to the correct position. That is likely why turning everything off and back on fixes it, because you are resetting the diverter valve position. A re-pipe, per the manual is needed

So this was my plan this summer. Should I just shut the system down on a warm day and try to put in a primary and secondary loop now? Or could I disconnect the secondary external pump and then wait until summer? 

1RandoGuy_RandoProb

MikeL_2 said:

   Is the red tubing connected to the multi - port manifolds rated for closed system heating? O2 barrier tubing?

It is I bought Mr. Pex barrier tubing. Especially because it's all in concrete.

1RandoGuy_RandoProb

Derheatmeister said:

Is the system installed in such a way that the system side circ can still operate while the DHW is producing hot water with the boiler circ. (Not wired to the boilers control but controled by the ZCB ) ? We would have: 1. Installed this in a Primary/Secondy piping or a Low loss header arrangement. 2. Have a Auto delta p/delta t cir on the system side (Hindsights you could install and adjust a bypass valve) 3. Have the boilers control supply power to the circs. 4. Installed the fill valve in such a way that the gauge is visal without a neck injury 5. Installed a service valve that has a drain on the expansion tank for proper maintenance. 6. Any relief equipment would have to be hard piped not using electrical conduit/PVC and within 6" of the floor as per our local codes in order to pass inspection 7. Installed a Codensate neutralizer in order to pass inspection ..Maybe you have one on the other side of the wall ? 8. Used PVC for the combustion air. 9. Adjusted the Boiler with a combustion analyzer. Maybe you did this? 10. Not installed the ZCB in a place were fluid can drip on it and short it out. 11. Any wires would have to be restrained as per code in order to pass inspection. 12. Drip leg on the gasline ? 13. Rotated the 1" return manifold Ballvalve so that it is accessable 14. Restained the 3/4" lines 15. Installed the Manifold restraints on the return manifold. As fenkel mentioned it could be a very small leak.. Based on the red flow indicators you may have also have some system fluid Maintenance requirements.. This Boiler was manufactured in 2020...Is this you first or second season? Maybe...For now,start by closing the Auto air vents on the Manifolds but leaving the Discal vent open. Hope this helps..

So this is the first system I have ever done and this is the first season it's ever ran. So super new to things but I tried.
So to your first question, I don't believe the system side circulator still runs during a DHW call. I have never checked but the pump is wired to the relay (or ZCB?).
I will say one of my suspicions has been that if I have a short DHW call things start to go bad and eventually things stop running. But that could be in my head. This summer I would like to have two different piping "zones" one for the internal circulator and one for the secondary. But I keep wondering if I should just unplug one of the pumps until then?

hot_rod

I don’t know that the mis-piping is directly related to the reoccurring air issue. The piping concern is the boiler not getting minimum flow it needs.
Fire tube boilers can trap a bunch of air up high in the heat exchanger. It slowly keeps working its way into the piping.
In some cases I would hold that relief valve open for 5 seconds or so to blast that trapped bubble out. With a bucket under the relief tube of course. It’s an easy try, be sure the fill valve is open, to add water as you blast it out.

Big Ed_4

You first want to test for leaks, shut off the boiler feed valve and watch the pressure gauge .