takagi tk2 problem error code not in manual

[wilfsdad1965]

i have owned this takagi for 4 years. i clean the filters out once a year. i have the remote panel. today during a bad storm, it suddenly fires up for no reason (no water usage) beeps and gives error code 21. this code is not in the manual. i was wondering if i'm getting water coming in from the exhaust valve (it's a side wall exhaust not straight up). it's only happened today during this really big storm when lots of rain is hitting the outside exhaust.

[wilfsdad1965]

actually, my paper copy doesn't have it, but the pdf from takagi does. error code 21 is vent pipe. i took the front panel off and there is water dripping down onto the base part of the inside. i don't think it's condensation, i think water is coming through the vent pipe and stopping the burner from initiating.

[SewerRatz]

But as you said the burner was firing up with out any water being used. I would be worried that some electronics might of gotten wet.