Help writing this. Heavy corrosion on hot water pipe at water heater:
You’ve already wrote it.
It could be a leak from the elbow joint?
Yes there is a drain pipe above the water heater. It leads to the exterior. My guess its an old vent exhaust pipe no longer needed.
It appears that the copper elbow above the water heater is leaking and sending corrosion down the pipe and onto the top of the water heater. I recommend a qualified plumber make repairs, as needed, to stop the leakage and return the piping to proper non-damaging integrity.
It’s heavily corroded and needs repair to help prevent water damage, I would not say where it’s leaking unless there is actual water there. It could be leaking from multiple places, best to let plumber figure that out. BTW, how old was the water heater? it appears to have been leaking like this for a long time.
Corrosion observed at the water heater water connection, recommend repair by a licensed plumbing contractor…done!
Water heater is about 8-9 years old.
Strange (and scary) house! It was built in 2005. Many kitchen appliances and water heater was replaced in 2011-2015!
High moisture in the space. Cold water is below the ambient air dew point.
Control the moisture.