We recently bought a 3,400 square foot, very old home outside of Albany, NY. No one lived in it for the fifteen years prior to our arrival. We're in the process of installing a new, high-efficiency propane boiler (a Westinghouse 199,000 BTU combination boiler, specs here). There are large, 4” cast-iron pipes snaking through the basement and branching off to about 20 cast-iron radiators (which are spread throughout the first and second floors). There are no zone valves installed yet, but we will probably want to install some shortly. The previous owners were using an old Weil McLain heating oil boiler. A few questions have come up:
• First, with regard to circulator pumps: Westinghouse says the unit has an internal pump but recommended installing an external pump. We found an old Taco 10-F1 pump among the piping that we pulled out (1/15 HP, 1.2 amp, 3250 RPM) but aren’t sure if we need something that powerful given that we’ll be using it in combination with the boiler’s internal pump. We’re considering the Taco 007-F5 (1/25 HP, .71 amp, 3250 RPM) and the Taco 10-F3 (1/8 HP, 1.1 amps, 3250 RPMs). Which do you recommend? Is there a way to more accurately estimate the size/strength of the pump we need? How critical is it that we get the right one? Would it be better to get a pump that has multiple speeds?
• Second, with regard to flushing the system: we’ve run fresh water through the existing pipes (most of which sat unused for a long time) a few times. The water went from a deep, sludge orange to brownish to, finally, fairly clear but still not perfectly so. We’d like to use boiler cleaner to really flush things out before we hook up the boiler and turn it on. Is there any way to essentially do a DIY power flush? Maybe using the new circulator pump? Or a separate sump pump and some kind of filter?
• Third, and finally, with regard to calibrating the boiler: we’ve read about combustion analyzers and gas manometers but aren’t sure that they’re worth the price, given that we’d really only be using them once. Are there cheaper ways to calibrate the boiler and propane systems? If not, how much should we expect it to cost to have a professional do the job?
Thanks a lot – and let me know if I can give you any more information!