Pressurizing the Baxi Luna 310 Fi Boiler

My new loft has a Baxi Luna 310 Fi tankless boiler, which means Skye will never run out of hot water, regardless of how long she stands in the shower. I was warned when I moved in that occasionally they have to be re-pressurized, but I haven’t had to do that. Until this morning. We didn’t have any hot water for the sinks, shower, or baseboard heating system, and the 30º and 50º lights were flashing. Unable to find the procedure in the manual or YouTube, I put out an A.P.B. on the loft residents’ email group. It didn’t take long for my phone to ring. One of my neighbors offered to come up and demonstrate the procedure. It’s super simple.

Step 1

First, place a small reservoir under the overflow pipe to catch any water that escapes through the pressure relief valve. I skipped this step and had about a cup of water drip onto my floor.

Step 2

Second, turn the small blue knob (see photos) under the Baxi unit on the right to open the valve. There are two blue knobs, so be sure to turn the correct one. A flashlight is helpful. Open the valve slowly and watch the pressure gage on the front of the unit. When the needle gets to 1 bar, close the valve.

That’s it.

It’s really only one step, but that would have seemed too simple for a whole blog post.

Flames inside my Baxi boiler.
My Baxi Luna 310 Fi boiler
Turn the blue valve knob (circled). Photo taken from below, left.
The valves under my Baxi boiler. Turn the blue knob (circled).
The pressure gage on my Baxi boiler.

One Reply to “Pressurizing the Baxi Luna 310 Fi Boiler”

  1. The flame picture is smokin’! I’m glad you live in a community with good people. ❤️

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