I have a quick question. I have talked to several local hvac companies, and I really need a second opinion. Have a 4400 sf brick home, outside of detroit mi. There is a 1955 US Radiator 200,000 btu hot water boiler in the basement now, 3 zones, 3 b/g circulators, and 6 relays (3 24v coil relays for the circs. and 3 110v relays for the burner). The furnace was initially oil burning with a domestic tankless coil in it. The boiler was switched to gas in the 1980s. After the switch, an electric water heater was installed, and the tankless coil was left disconnected from water. When that electric water heater went, it was replaced with a normal gas unit. Now- The question: I want to re-use that tankless coil to heat water ONLY during the winter and ONLY for half the house (kitchen, laundry- high temp.) Now I dont mind opening and closing a few valves every spring/fall, but the question is how do I have the HVAC co set up the aquastat. I assume, that originally, the boiler had a triple aquastat which kept the boiler "warm" year round. Now there is a single aquastat, acting as a "high limit" set to i think 160 degrees. The burner and aquastat only get power when a circulator/zone is active. Since i shut the boiler down during the summer, do I want a triple aquastat installed, or should I just feed the existing aquastat 24v 24/7 during the winter ? I know that years back, the space heating operated on the high portion of the aquastat, and the water heating operated on the low side, since it represented such a small load, but since I have a large hot water demand, can I just run the boiler at one temperature (160-180) Thanks a lot, I appreciate the help. Also- when i have my hvac co come out and replace the aquastat and hook up the plumbing, has anyone had good luck with a particular brand of aquastat?
- posted
17 years ago