re-filling efm 520 boiler system

I think my nest step is going to be to take those out and see if it's clogged or something. I would think pulling the lever up would fill it.

It should most definitely.

Of course it's in a place that makes it a PITA ti take out.

Of course! It wouldn't be right if it wasn't! Keep at it, you'll figure it out.

It's filling! The regulator was stuck shut. Thanks for all of the help!!

Good to hear!

I ended up having to replace the regulator and safety valve. I got it to fill but the regulator stuck open then. When the safety valve popped, it too stuck open and was dumping water all over the floor. When I took everything apart, the pipe before the regulator was packed full of rust and sediment. The pipes are now all flushed, a new reg/valve setup is on, and it's purring like a kitten.

A whole house filter would be a good investment, as well as a water softener if you don't already have one. I have both here, the water is very high in Calcium Carbonate as well as iron. My water filter usually needs to be replaced anywhere from once a month to once every 3 months, depending on the amount of sediment in the water. The softener will remove some iron, if it is very high then a separate unit should be installed to remove it. I had issues with the softener not removing the hardness anymore, had to flush the unit with "Iron Out", the iron had encapsulated the resin beads in the softener. Now I add a layer of an iron removing chemical after each bag of salt in the brine tank.

I'm on city water and have had it tested, it's actually not real high in iron and it's very good quality. I'm also not a fan of soft water. Mine is not ultra hard though. I do think the whole house filter is a great idea. That furnace has been down there for 40 years and i think the reg/relief is pretty old too. I'm wondering if the thing has had issues since before I moved in 7 years ago. The radiators have always gurgled a lot when the heat comes on, even after I bled them. After repairing everything yesterday, and bleeding the system, they are silent. They heat up quicker too. The furnace doesn't run nearly as long as it did before. I am really happy with it now.

Probably just deposits that accumulated over time, I thought you were on a well. The whole house filter couldn't hurt, and they aren't that expensive. You'd be surprised what that filter removes.