Bought a home three years ago with two Raypak H3-01803 residential boilers. I know they are very old. Do not know when the previous owner had them serviced but they did look to be in good condition. Just wanted to know is this something a handy person can themselves? Or should the system be power flushed? What is the typical flush interval? What is a typical price to pay for boiler flushing? Looking on google it says every year with the prices between $100 - $600. That does not seem correct to me.