How to find where air is getting into baseboard heating system

[tkyanks]

Hi, new member here. Appreciate any help I can get. We have lived for 15 years in an old house with cast iron radiators. The previous owners added an extension several years prior and it's heated with baseboard heating. We've always had to occasionally add some water to the system but that's never been a big deal.
This year our boiler has had some air locks which has caused it to generate tremendous noise and it sounds like it may burst pipes. I've drained air out of the system but it's happening too frequently.
We had two projects done by the extension this spring and I'm afraid something in the heating system has been damaged and I'm looking to see how leaks in a baseboard system can be located.
The first project was spray foam insulation put in the crawlspace under the extension. The pipes for the baseboard system go into and return from this crawlspace. The second project was a new vinyl floor put in the extension. That was in the den on the first floor but it was also close to the pipes.
Is there some sort of pressure test that can be used to see where a leak could be occurring. I look in the crawlspace but I don't see any signs of water. Apologize for this long post and appreciate any help someone could provide

 

[WorthFlorida]

First thing is check the expansion tank. If it had never been changed out, it'll be a steel tank up on the ceiling. It should be drained once a year. There should be a valve before the tank to turn off the water from the system. The tank itself will have a drain valve. If it's a new bladder type, check the pressure. If water spits out then the bladder is bad.

Read this recent post. You may need to do the same.

No heat only at last two baseboard heaters

Hi everyone. Remodeling lower room in home had access to heating pipes so updated to rooms to slant fin baseboards from cast iron. Decided to change 20yr working old circulator pump, drain valves, and leaking hi- vent at burner. Put heat on bled every baseboard, drain , etc. Now have heat at...

terrylove.com

I'm not saying that this is the cause but just basic maintenance and eliminate a possible source. I grew up in East Meadow and every year my dad had me carry up a flight of stairs what seem like 100 pails of water that drained from the tank to dump outside.

 

[Sponsor]

 

[Fitter30]

System should always be under pressure 10lbs for 1 story house. Boiler system under pressure would leak water being under pressure. Take some pics of boiler, piping and expansion tank.

 

[John Gayewski]

What kind of heat is this? You have loud banging that sounds like the pipes could break?

 

[tkyanks]

Thanks for the replies. We have steam radiators and when the previous owners built an extension they put in baseboard. So the pipes for the baseboard go in and out of the one boiler. The technician that came to the house emptied out about a bucket and a half of water (and air, too, I guess) out of the system. That seems to fixed the issue for now. He did mention that the pipe coming out of the boiler going to the baseboard should have an air vent at the top of it. Similar, I guess, to the air vents we have on our radiators. We'll be looking into that.
We don't have an auto fill system for the boiler and we did over fill the boiler a bit. This caused the pipes to bang. That's been taken care of, too.
The loud noises coming from the boiler were due to too much air in the system and it put the circulator (?) under stress. Once the air was removed the boiler functioned properly.
I think we're OK now and will look into getting an air valve for the pipe coming out of the boiler.
Thanks for the replies.

 

[Fitter30]

So your using the steam boiler water to heat the baseboards that use boiler water with no heat exchanger? Both pipes feeding the bb under the water level? Any valves have packing glands? Air can enter though them. Does the condensate go back to condensate tank or direct into boiler? One or two pipe system?

 

[John Gayewski]

In the future mention that this is a steam heating system. It operates very differently from a hydronic hot water system.

Air is gonna be a normal part of your steam operation. That would not cause the banging only water in places or shouldn't be would cause that.

It sounds like you have it figured out for now.

 

[tkyanks]

So your using the steam boiler water to heat the baseboards that use boiler water with no heat exchanger?
Yes
Both pipes feeding the bb under the water level?
Yes
Does the condensate go back to condensate tank or direct into boiler?
Direct into boiler. I do not see any condensate tank.
Any valves have packing glands? Air can enter though them
I don't know. Nothing that I can see
Thanks for your responses, appreciate them.

 

[Fitter30]

A bypass line around around the boiler from the condensate return to the bb heater pump will do two things one is keep the water temp around 180° second keep the water from flashing into steam in the volute of the pump.