Hi and thanks to those who read and respond to my post.

I think the oil furnace boiler is leaking water internally. I did my spring furnace clean, and found the soot in the bottom of the boiler inside was moist. Before, inside was VERY dry and easy to vacuum. Soot does not smell like fuel oil. The concrete pad around it and the water heater is damp, but not wet. (Gas Water heater just replaced and problem remained). There is also evidence of water in the flue pipe, with dried rust stains on outside of pipe. The furnace was very noisy this season at shutoff.

Is this a leaking boiler, or could it be something else? Is is repairable, or time to replace? The hot water unit (Vaillant) is about 20 years old. The Igniter unit (Blue Angel) is about the same age.

Thanks for your help

You could have a hole in your chimney cap, and rain coming down threw.

Thanks,
I checked the rain cap, but its looks OK. That would have been an easy fix. Plus, the concrete pad under the furnace and hot water heater is damp, and we have not had any rain for at least a week.
I now see that the concrete is dampest at the corner where the water supply enters this utility room. The pipes and whole house shutoff valve are dry inside the house. Could I have a leak underground enroute to the Water meter at the street? This still would not explain why the INSIDE of the boiler shows moisture.:confused:


You could have a hole in your chimney cap, and rain coming down threw.

Could have a main water line leak, or if it is real hot and humid you may just be having a condencation problem

[fix] water leak in oil furnace
http://dailytweak.wordpress.com/2013/01/30/waterfix-leak-in-oil-furnace/

Rust on the flue pipe is only from condensation. Water around the base and inside the furnace is probably telling you that there is a leak in the cast heat exchanger. After 20 years, this would not be considered uncommon. It's expensive but think about installing one of the new high efficiency furnaces out there. They are smaller, do an incredible job and are very fuel efficient.