Viessmann B1KE f380 faults

mattyc

Out of several installations of the new Viessmann models of boilers (B1ke/B1he), most have worked flawlessly. On occasion, several units (so far only the combi boiler's) express an F.380 fault code which is flame loss immediately after stabilization. Resetting the boiler will have it running fine sometimes for weeks or months without further issue. The units that have the issue are all located in the same development and run on natural gas. Gas pressure is within ranges, combustion results are all within range. The fresh air and exhaust piping are sidewall vented. Clearance from fresh air to exhaust is correct according to the install instructions. I have tried replacing the ignition electrodes and the ionization electrodes and cleaned the heat exchangers. Sometimes this works, sometimes it doesn't. Sometimes we continue to have issues (Randomly). The only other thing with this specific development is that it is located about a mile or so off of the long island sound. The wind does blow through that area quit strong at times. Could high winds effect flame stabilization? Have any other installers run across this issue and had true fix for the problem? Thanks in advance.

GGross

What are the actual gas pressures?

the way to test is to record static pressure, the value after ignition, run to high fire and record the lowest value, turn off boiler and record the lockup pressure, ideally this is done with all gas fired appliances running. if you have a drop near or greater than 1.0" (0.5 ideally) wc you need to fix the gas line

What are the actual combustion results?

What size and how many elbows are on the exhaust system? (b1ke really needs minimum 3" poly) add together length and number of ells for both intake and exhaust

Where are the intake and exhaust located outside in regard to each other? The minimum clearances that ANY manufacturer give are only minimums, and can not guarantee that recirculation won't occur

My B1HE is located with the exhaust and intake facing directly at the wind, 50mph winds have never caused an error for me or any of my customers (several hundred out in the field) that is not to say it's impossible, and I certainly wouldn't recommend installing it like that, but I would record all necessary values and report back with pictures of the intake and the exhaust. On a relatively new install if I had to take a guess I would go at gas pressure and recirc, it's nearly always gas pressure or recirc