TOPIC: Rust under draft hood of water heater

I'm looking at an 11 year old water heater.  It shares it's vent with a 50+ year old gas fired boiler.  Does this rust come our of the water heater flue and is evidence of an old appliance?

Do you have any pics of the flue of the boiler and water heater?

What did the chimney look like, was it capped at the exterior?

I would guess the 50 year old boiler is probably the cause of the rust/debris.

I would think a clean and check of the boiler and flue would be a good recommendation.

Also did you check the appliances for backd rafting with a mirror or some other method of checking.

I have seen moisture from condensation in cool areas cause rust on flue pipes.