Circulatory and air purging

QMPenn

Very quick question. The former owner of my house has the hot water going to the taco circulator and then about 6” away is a spirotherm air eliminator. I keep getting air in my system and every couple of months I have to bleed the air out of this zone. I don’t feel that the spirotherm is eliminating air but it is working. Does it matter if the spirotherm is before or after the circulator? This is the only thing I could think of as to why there is a buildup of air. Any advice is appreciated. 

STEVEusaPA

What's the relationship between the circulator, the expansion tank and the air elimination? And what type of expansion tank-steel or bladder type?

QMPenn

I figured photos would work better. Expansion tank is a bladder type. Let me know if you need anything else.  

HomerJSmith

Your circulator is mounted incorrectly. It should be mounted in a horizontal position.

Are you pumping into the boiler, in other words, is the pump on the return to the boiler? If that is the case, it would be possible to pull air into the Spiro vent.

The pics you posted are kinda dark and it is hard for me to decipher what is going on. More pics from further away and put a little light on the subject, would be helpful.

EBEBRATT-Ed

You have a few things wrong. The Taco pump is not supposed to be mounted with the motor up. The motor must be horizontal. Looks like you have a 3 way valve that is not piped right.

Need more pictures to tell

hot_rod

Odd piping from what we see. Looks like the low water cutoff switch is mounted kinda low also.
I see several circulators above the boiler looking like they are pumping into the return, and the upright one pumping away? Bigger pics or a sketch maybe.
The Spiro can get plugged, a small opening near the top, does it look to be clear and open?

With a ball valve closed that much, looks like an attempt to force flow in a certain direction?

What is the pressure on the system? For a two story home you would want 12- 15 psi, too low of a pressure can be the cause of poor air elimination, especially when combined with poor expansion tank connection.

QMPenn

So here are some better photos. Pressure is about 15 psi. I was fiddling with the ball valve to see if there was a difference. 

Circulator above the boiler go to different zones. No issues with those. 

Spiro is not clogged. Does it matter if it is before or after the circulator?
I am pumping away from the boiler. 

I appreciate the help and response and hope I answered everyone’s questions.  

It wouldn’t be difficult to rotate the circulator to the correct position.  Should I start with that or do I need to have the circulator in front of the spiro? The other option is I relocate the circulator to the vertical pipe with the insulation on it. 

Henry

One is supposed to have 5 dimensions of straight pipe before a circulator and a minimum of three dimensions after. This is not done in your case. Your pump may be cavitating. We standardized at 5 and 5 as it it is easier for a plumber to remember. Place the pump motor horizontally!

hot_rod

The best air removal is at the hottest point in the system, so right at the boiler is ideal, looks like that is what you have?
\
The relationship of the pumps to the expansion tank connection can be the root of chronic air removal evils. The expansion tank should be on the inlet side of all the circulators. BUT, when you have some circs pumping into the boiler, and some pumping away, which I think is what I see, that becomes a bit of a challange.

Cranking down a ball valve can cause cavitation which appears like an air problem, try opening that valve 100%.

If those are Taco 007, and you have 15 psi, I doubt you are pulling air into the Spiro, they do not develop enough delta P to pull the system sub atmospheric.

Is this a new problem? A good power purge could get it noise free if it worked in the past. The up and down pipe sizing is weird, it could use a better near boiler piping, get all the pumps pumping away from the expansion tank, better pipe sizing, etc.
Is there some low temperature radiant? Not sure what that 3 way valve is supposed to be doing?

I think you would need to get into this $$ deep to correct all that piping.

QMPenn

hot_rod said:

The best air removal is at the hottest point in the system, so right at the boiler is ideal, looks like that is what you have? \ The relationship of the pumps to the expansion tank connection can be the root of chronic air removal evils. The expansion tank should be on the inlet side of all the circulators. BUT, when you have some circs pumping into the boiler, and some pumping away, which I think is what I see, that becomes a bit of a challange. Cranking down a ball valve can cause cavitation which appears like an air problem, try opening that valve 100%. If those are Taco 007, and you have 15 psi, I doubt you are pulling air into the Spiro, they do not develop enough delta P to pull the system sub atmospheric. Is this a new problem? A good power purge could get it noise free if it worked in the past. The up and down pipe sizing is weird, it could use a better near boiler piping, get all the pumps pumping away from the expansion tank, better pipe sizing, etc. Is there some low temperature radiant? Not sure what that 3 way valve is supposed to be doing? I think you would need to get into this $$ deep to correct all that piping.

All the circulator are pumping away from the boiler. I think the problem has been there, but I feel it has gotten worse. If I overhaul the system I would get a professional to redo it since I am definitely not one. 

QMPenn

Henry said:

One is supposed to have 5 dimensions of straight pipe before a circulator and a minimum of three dimensions after. This is not done in your case. Your pump may be cavitating. We standardized at 5 and 5 as it it is easier for a plumber to remember. Place the pump motor horizontally!

I will make it horizontal. What do you mean by dimensions?

EBEBRATT-Ed

And the backflow preventer has a plug in the drain opening

QMPenn

EBEBRATT-Ed said:

And the backflow preventer has a plug in the drain opening

The plumber I had replace the water tank told me it was redundant. 

QMPenn

So I rotated the motor. Let’s see what happens. 

hot_rod

The Spirovent is your central air purging device, but it is only on one 3/4 loop? It should be on the larger 1-1/4"? pipe coming off the boiler to capture air for all the circuits. Currently air needs to get into that 3/4 zone to hit the purger.
Also it looks like a float type air vent right after the fill valve? Might try closing the cap on that also. Float type vents can allow air into systems.

With some tweaks you may get it to an acceptable performance, but it is not exactly "textbook"

QMPenn

hot_rod said:

The Spirovent is your central air purging device, but it is only on one 3/4 loop? It should be on the larger 1-1/4"? pipe coming off the boiler to capture air for all the circuits. Currently air needs to get into that 3/4 zone to hit the purger. Also it looks like a float type air vent right after the fill valve? Might try closing the cap on that also. Float type vents can allow air into systems. With some tweaks you may get it to an acceptable performance, but it is not exactly "textbook"

I just rotated the cap on the float vent to close. Thanks for the tip. I agree that there should be an air purging device on the larger pipe. Thanks for the tip!