Handyman and more helped me with two projects (cleaning up a back door trim and fixing caulk/grout in a bathroom) they were honest, professional and did a great job! we will definitely being using them again! Your flow rate multiplied by . gives you a rough idea of how powerful a boiler you’ll need in kilowatts, assuming your cold water comes in at about c your installer will be able to check your temperature and flow rate and help you make an accurate assessment. Don’t let.