boiler repair

https://brightquillio.com/s/5v_AHPrxE6HC1mfbxe4VV

The boiler started making that ominous banging noise again, so I finally called a repair guy. He said the heat exchanger was partially clogged with sludge, which explained why the radiators were lukewarm. After he flushed the system, it ran quietly and heated up in minutes. Simple fix, but I'm glad I didn't ignore it.