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too much pump for this hydronic system?

For a 4 zone radiator system 2 bedrooms/bath/family room with no more than 20 feet from the heat source to the most remote zone valve and with less than 4 feet rise in elevation from under the house to room level, do I use a Grundfos that draws over 2 amps to run a Takagi Jr. or do I go with an Embassy BMS boiler unit that has a built in Grundfos that draws less about .75 amps. It seems to me that with the Takagi I will be running the pump continuously as long as a zone valve (Caleffi) is open. Bypass valves will be used to make sure the pump doesn't turn the one radiator into a noise maker should the other 3 zones be off/closed. I think the boiler has a 4 gallon tank holding the hot water and most likely the .75 amp pump runs intermittently. I am wondering if the Takagi Jr. is the best choice for my simple closed loop system here just north of San Francisco or if I should opt for the slighty pricier boiler system? I am getting the image that the Takagi, which is excellent as my domestic water supply (a TK-2) is perhaps not the best candidate to run my small, closed loop hydronic system. It seems a 1/25 hp pump just makes more sense than a 1/12 hp. Would there be condensation issues with the Takagi and why? And is that important. I haven't run the numbers yet but it seems the larger pump would be drawing 250 watts continously until my son's bedroom goes from say 50 degrees to 70 degrees. At 140 degrees temperature which is the Takagi's temp, it will take longer to bring that room to temperature and with a larger radiator than if I am running the boiler drawing less than 100 watts from the pump running intermittently, at 180 degrees, at 87 AFUE rather than I think 81-84 for the Takagi Jr. Thanks for any help.


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