Hot Water Loop / Hydronic Zone - Purge Air

rhe587

I've recently had my annual boiler service done for my steam system but I'm not getting heat off the hydronic zone/loop which goes to a baseboard in my master bedroom only. The pump runs but the hot water is not making its way back. This has happened before and the person purged the air out of the loop to resolve it but I didn't pay attention at the time to see how they did it. Can anyone advise based on the photos on how I would go about doing this? I'd like to give it a shot before calling the person who did the maintenance back. Thanks!

EdTheHeaterMan

This is a tough one. I have been looking for a short video clip in heating help video arcives that explains how to use the hot boiler water that is below the water line to run a small hot water baseobard zone. I know that I have seen and viewed it in the past, but for the life of me, I can't find it. There are visuals and diagrams that help you to understand how it works. Perhaps @Erin Holohan Haskell can find if for us.

The reason I say it is a tough one, there is more than one way to do this, and unless I was on site to see what each valve and flow control is doing, I would not be able to tell you from Just your photos. It will take some time to draw out what you have and why there are 2 flow control valves.

The basic concept is that which allows you to lift a straw out of a glass of water with your finger over the top end, and the water will stay in there, unless you lift your finger off the end of the straw so air gets in, or the bottom of the straw is lifted above the surface of the water to let air in. It the same principal that allows you to siphon water up over the top of a container of water, as long as the outlet of the siphon tube is below the water level of the container.

You may need to bite the bullet and call in the pro that did it before and have your video camera ready to see all the steps.

EdTheHeaterMan

I was able to find this illustration form the video but still cant find the video clip.

The whole thing is explained here.

https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/

You can ignore the first 8 questions because they don't apply to you. Q. #9 is what is in my illustration above, and the rest of the Q. go on to explain how it works and how to purge the air from the higher than water line radiators.       

Hope this helps.

rhe587

thank you very much for the thoughtful response!

Erin Holohan Haskell

@EdTheHeaterMan, that's the article I was going to point you towards. I'm not sure that we have a video clip on this. I don't remember one and haven't been able to track it down within our archives.