Trying to post again,I have several flex duct branch runs with water in them. Any ideas what causes this? How would you write this up?
Where r these ducts located. Attic, crawlspace etc. i assume these r heating ducts. Are they insulated? Sounds like condensation build up but need more info better description Photos?
Without knowing more or seeing pictures, one could say “There are several flexible ducts with water in them. This is not correct. Have a qualified HVAC professional investigate and correct the problem(s), now, before additional damage and problems result.”
Unconditioned crawl space. They are insulated flex duct
Ducts in unconditioned crawlspaces are not wisest choice. Too high moisture ruins insulation. Major problem with flex duct is if not perfectly stretched out , its gonna sag and be a collection point for condensation within ducts. Rigid ducts way to go insulated if you must put ducts in crawlspace
Water could also get in through the registers, by the doors, any wet or snowy boots? Kitchen, bathroom, wet mopping
I’m curious how did you notice the water in the ducts?
If this was the cooling season I could give some possible causes but in the winter time makes no sense has to be a external to the duct system problem. The only water associated with heating mode would be a humidifier and is generally on the return side of a furnace.
You can disregard all the talk about sags and location in the unheated crawlspace. That is just total nonsense…