Welcome! Here are the website rules, as well as some tips for using this forum.
Hello all I have a 4 panel Viessmann 200T system direct flow through 18 tubes per panel. Got a call from the homeowner last week the Resol controller was reading 270 deg. Not good, went out and looks like a power failure had caused the panels to stagnate. Flushed out the burnt up viessmann tryfocal glycol with TXP and repurged. System ran over the weekend but got air locked. Burned up the new glycol but today was on site and trying to purge the old system and could not get flow throughout the array, before I was able to cover the panels I was seeing collector temps of 385 deg. Talked to some people and steam lock came up. I tried to blow the system out after covering the panels with a 1/2 hp purge pump as well as with 80 psi air to no avail. Any thoughts would be greatly appreciated. Thanks Matt