Air in Hydronic System causing no heat

[Jsf721]

This last weekend the heat in one zone started dropping 1-2 degrees a day. Finally it was off 10 degrees to the termostat. I did have good air flow and when I touched the supply and return lines at the air handler, they were not hot.

I bled the system and a bunch of bubbles came out. Its a band new 2 year old system. Last winter same issue and the company came back to bleed system and said, now that its out it should not return.

Well its a good thing I watched bc it happened again. After bleeding the system it is working perfectly. How to I solve this issue once and for all. There is a little brass cylinder size of a coke can with a twist top that is supposed to remove air. it is near the manifold.

Advice and links are appreciated as I do not have the expertise and I will be speaking to the company I would like to have some suggestions.

 

[American Locomotive]

It sounds like your automatic bleeder isn't working, or isn't installed correctly, but also generally speaking once the air is purged, it should never have to be purged again.

You might have a leak. Does this system have an automatic water feeder?

 

[Torque&Recoil]

What American Locomotive said. My last house had a hydronic system, and over 25 years, I never had issues with air in the system. It should be plumbed into the water supply line, so more water enters the system to take up any lost by leaks. I did once replace the air separator, but that was because it was leaking water, not because it wasn't removing air. The only times I ever bled the system were when I drained it to install new zone valves and once when I added another radiator.

Just a thought - my system was installed with zones being different floors of the house. If only the zone valve for the upper floor was open - the circulator pump pumped water up there regardless of a few bubbles. You could hear the bubbles gurgling through the system, but it still worked. The only way the lines would be cold, would be if the water level is so low that the pump is sucking air (like totally out of water). Is your system installed so that a zone encompasses different floors?

 

[Jackfre]

I like Spiro-vent systems. I replaced the old separator with a SV on our MA home and air problems were eliminated. Depending upon how your system is piped it is possible that the location of the Circulator relative to the boiler/expansion tank is creating a partial vacuum which draws air into the system. This especially if there is an auto air vent on the system. For reference, and if you own a boiler and have any interest in it, Dan Holohan’s, excellent ‘Pumping Away” will make you bleary eyed on the topic. Sit in the boiler room, read the first ten large print pages while identifying the relationship of Circ, boiler, Exp tank and you may know more than your servicing dealer. At the very least if you have the dealer back out you should follow him and get instruction in bleeding air out of the system.

 

[fitter30]

Take a few pics of the boiler,piping, pumps, any zone valves and gauge.

 

[Jsf721]

It sounds like your automatic bleeder isn't working, or isn't installed correctly, but also generally speaking once the air is purged, it should never have to be purged again.

You might have a leak. Does this system have an automatic water feeder?

Yes it does but I do not see any leak that is evident.

 

[Jsf721]

I like Spiro-vent systems. I replaced the old separator with a SV on our MA home and air problems were eliminated. Depending upon how your system is piped it is possible that the location of the Circulator relative to the boiler/expansion tank is creating a partial vacuum which draws air into the system. This especially if there is an auto air vent on the system. For reference, and if you own a boiler and have any interest in it, Dan Holohan’s, excellent ‘Pumping Away” will make you bleary eyed on the topic. Sit in the boiler room, read the first ten large print pages while identifying the relationship of Circ, boiler, Exp tank and you may know more than your servicing dealer. At the very least if you have the dealer back out you should follow him and get instruction in bleeding air out of the system.

do you have a link a google of spiro vent systems did not product anything I though was what you were suggesting.

thanks

 

[nadogail]

Air in Hydraulic or Hydronic systems is bad news, get rid of it.

 

[Jsf721]

Air in Hydraulic or Hydronic systems is bad news, get rid of it.

Not happening Just installed. Will fix it

 

[Jsf721]

I like Spiro-vent systems. I replaced the old separator with a SV on our MA home and air problems were eliminated. Depending upon how your system is piped it is possible that the location of the Circulator relative to the boiler/expansion tank is creating a partial vacuum which draws air into the system. This especially if there is an auto air vent on the system. For reference, and if you own a boiler and have any interest in it, Dan Holohan’s, excellent ‘Pumping Away” will make you bleary eyed on the topic. Sit in the boiler room, read the first ten large print pages while identifying the relationship of Circ, boiler, Exp tank and you may know more than your servicing dealer. At the very least if you have the dealer back out you should follow him and get instruction in bleeding air out of the system.

found it -thanks

 

[American Locomotive]

Yes it does but I do not see any leak that is evident.

Hyrdonic system leaks can be tricky, as the heat causes the water to evaporate and dry off quickly. Check all the piping you can see for signs of corrosion or deposits. If you see a pipe, fitting, or coupling with a blue/green build up or streaks of white crystally looking stuff - that is a leak.

 

[fitter30]

Delete

 

[fitter30]

I like Spiro-vent systems. I replaced the old separator with a SV on our MA home and air problems were eliminated. Depending upon how your system is piped it is possible that the location of the Circulator relative to the boiler/expansion tank is creating a partial vacuum which draws air into the system. This especially if there is an auto air vent on the system. For reference, and if you own a boiler and have any interest in it, Dan Holohan’s, excellent ‘Pumping Away” will make you bleary eyed on the topic. Sit in the boiler room, read the first ten large print pages while identifying the relationship of Circ, boiler, Exp tank and you may know more than your servicing dealer. At the very least if you have the dealer back out you should follow him and get instruction in bleeding air out of the system.

Saw Dan at a 1/2 day seminar in 1974 or 75 in St. Louis think it was put on by Weil Mclain boilers. Got signed copy Pumping Away was selling his paperback books. His web site heatinghelp.com
Follow him in a trade magazine had a monthly column back then. Still read his book every year or two.

 

[Jackfre]

Saw Dan at a 1/2 day seminar in 1974 or 75 in St. Louis think it was put on by Weil Mclain boilers. Got signed copy Pumping Away was selling his paperback books. His web site heatinghelp.com
Follow him in a trade magazine had a monthly column back then. Still read his book every year or two.

He is such a pleasant guy and just knows how to present information to the trade and beyond. Living in New England and working all the area trade shows I got to see him quite often. I was always on HH but not so much any more. I will still just pick up “Primary/ Secondary or Pumping Away” just for the heck of it and enjoy it always.

 

[NightSky]

He is such a pleasant guy and just knows how to present information to the trade and beyond. Living in New England and working all the area trade shows I got to see him quite often. I was always on HH but not so much any more. I will still just pick up “Primary/ Secondary or Pumping Away” just for the heck of it and enjoy it always.

He has several interesting Youtube videos. One example:

.

 

[fitter30]

Worked on some old mansions 1900 to 1940 that are across from Forest Park where In 1906 hosted a worlds fair. They had some of the very ornate radiators and some used a webster sytem that ran in a slight vacuum with a high pressure switch set at 1/2 lb. Father ran service had to bring him in to explain to me which i can't remember. Hot Springs, Arkansas has bath houses that can be toured they have some really beatiful odd shaped radiators.

 

[NitroGarage]

I may have missed it but does this zone have a flow control valve? Possible flow loss?