The inside of my old boiler

seized123

I have no idea what the inside of a boiler should look like, but here it is. It’s a Weil-McLain WGO-3, ran for about 22 years and eventually leaked. (The one before it had a shorter life.) The new one is identical to both of those.

We have aggressive water with high tds, no water softener but we do have a neutralizer for pH. In the spring I plan to add treatments suggested by @hot_rod and a micro bubble air separator as per hot rod and @SuperTech, and anything else anyone might suggest looking at these pics.

Notice streaky looking marks on back and side of assembled boiler. And inside the holes it looked blackened in spots.

EdTheHeaterMan

What is that boiler connected to?

• Copper baseboard
• Large cast iron water filled radiators
• Steam system
• Radiant floor tubing
• Air handler with hot water coil in the ductwork
• Convectors
• PEX tubing without a oxygen barrier
• something else?

The color of the cast iron flue gas side may indicate condensation of flue gas over the years of service. but the black coating on the water side is a little troubling. That sounds like your water chemistry should be adjusted and monitored for the lofe of the system. I have seen that boiler last twice as long as your's are lasting.

seized123

@EdTheHeaterMan it’s copper baseboard and indirect hw.

I thought of adding the below stuff which hot rod suggested:

EdTheHeaterMan

@hot_rod is my go to guy for water quality questions. I would follow his recommendation.

The reason I asked about your radiator system… If you have a large volume system like cast iron radiators, then your near boiler piping might have been an issue. With Copper baseboard, that is not the case. You should not need any special piping to prevent flue gas condensation on an oil boiler connected to baseboard loops. Just make sure that you have a good exhaust temperature that does not get too low. 350° to 400° should be fine. Just don't underfire the boiler and end up with a stack temperature below 350°

seized123

@EdTheHeaterMan thanks. Last couple checks the temp was about 410F.