I heard some gurgling in our baseboard heat recently, so I decided I should bleed the air out of our system. Never having done this before, I watched a few youtube videos to familiarize myself with the procedure. The basic idea seemed as follows:
- Turn off the boiler
- connect a garden hose to the zone's output spigot
- turn off the valve below the output spigot (to prevent water from cycling back through)
- turn the switch from auto to manual so that the water will flow out the spigot.
- in some cases, videos recommended turning the refill valve from normal to fast-fill to speed it up, or to have enough pressure to push air through an upstairs zone.
I did this, and nothing happened. And in the process, I looked around for the refill valve switch to put it in to fast-fill...and I couldn't find anything that looked like the ones from the videos. Well, I found one thing that looked a little like a fast-fill thing from one of the videos, but it didn't seem to do anything. And there was no flow at all - not just slow flow.
After poking around, I found a valve that, when I turned it, I heard the flow of water, and so feeling brave, I left it open and a little while later, lo-and-behold, water (and air) was coming out the other end of the garden hose.
So I went through each zone, opening and closing this valve for each one. I didn't want to leave the valve open once I closed the zone valves, since in the videos, people made it clear that leaving systems in 'fast-fill' mode with the spigots closed could cause pressure to build up and blow out the high-pressure release valve. I didn't know what the pressure of this input was, so being cautious, left it how I found it (closed).
But my question is this - is it a problem if the refill valve is closed normally? My impression is that this exists to replace water that leaves the system over time. I don't know exactly where this water would be going (absent a leak), but the fact that each of the systems I saw on the instructional videos had them made me think it is standard for the refill valve to be applying a constant input source (of around 12 psi, I think). But my system seems to have just a manual on/off, and it seems to live in the off position.
Here are some photos of the system to give you a sense of what I'm working with: