Air lock no heat

I put the shop loop in the other day, 2 baseboards upstairs which is the highest point in the system, added a ball valve to bleed air while filling, will add auto bleed this week could not find one on the weekend.I filled the system with a hose in the boiler room using a 15lb regulator on it bled the air off in the shop and thought the auto bleed in the boiler room would take care of the rest as I had the make up water on.Finally the problem I don't think the make up water is getting into the system as the supplier talked me into a 20lb regulator on the make up water line as to not fill the expansion tank , The auto bleed is about 15ft above the make up water and i don't think 20 psi is enough to activate it.To get the heat going I shut the expansion tank off and used the hose without the the regulator the auto bleed worked as it should , disconnected the hose and opened the tank it worked last night.

I had troubles getting air out of one of my two upstairs zones. I think I have it all out now just by turning the circ speed up and closing all the other zones with a drain open at the bottom of that one zone return to let the air out. I did that a few times, after one try with a garden hose that I thought got it all but didn't. There was a little bleeder valve on the top of the zone in a bedroom that was put in on the original install but I didn't want to touch it as I remember them having issues with them leaking a bit back then. But in all the air chasing, the auto vents I have kept spurting out little spurts of air once in a while with no more that 15psi in the system - so I would think the 20psi you were using would have been lots for that? It didn't seem to take much of an air pocket to stop the flow.

Thanks Maple, I'll try turning up the circ .Did you leave it at the higher speed after the air was purged?The reason I ask is that I have a non pressurized boiler going to a plate exchanger feeding a pressurized secondary just wondering about the increased flow and the efficacy of the heat exchanger.

Once the air bubbles seemed to stop coming out the drain and I couldn't hear any air in the pipes, I closed the drain, opened the return back up & turned the pump back down. Like I said I did it a few times, last couple there was only a little burp of air that came out the drain.

It happened again. I spent 2 hrs in the crawl space soldering fittings on my back to install cast iron rad in the old house no fun., anyway the pump air locked again after the lines were filled and the rad bled. I turned the speed up,after an hr no difference., I had to connect a hose to the system to purge the air out.The pump is high in the system , should I move the pump to the basement or move the make up water source up to the shop? All I know is that I don't want to drag out hoses when winter really hits.

Sounds like you are not getting a good, clean purge.

A valve like this, from Webstone, allows you to connect a hose and power flush the zone. This valve allows you to purge either direction.

With high points in the system, it is a good idea to add a float type or hydroscopic vent at the upper most point. This will collect and vent any small bubbles that can occur when you heat up the water.

Thanks Bob I'll try it.