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My building has convectors in each unit, they are 2-Pipe supply and return. In winter its hot water circulating from the boiler and in the summer this switches to cooled water. At times they need to be bled to get the air out of the coil for heating or cooling. Lately we've been running into other issues.
The lower apartments have been submitting work orders for no AC. The convectors are having flow issues, it seems that either supply or in many cases the return line is clogged. (Sometimes the coil) It is brown rust, sludge, etc.
What is the best way to clean this out? Suck from the supply line? Push through the coil? Push the return?
What equipment? Pump?
Any help would be appreciated.