I am looking at getting a OWB to heat my indoor swimming pool (in Michigan) and enclosure and possibly a pool barn down the road. I am looking at about 500,000 btu so I can accommodate the barn down the road. I have been looking at a Central Boiler brand with a duel fuel (natural gas) option so I don't have to burn wood in the summer when my heating load is minimal I don't have to use wood. Does this sound like a good option? Does anyone have experience with an indoor pool or with the Central Boiler brand? Any feedback/help would be greatly appreciated. Thank!

We have an indoor pool over here in Green Bay, Wisconsin but it is heated with geothermal. Your pool contractor shouldn't care much how it is heated, I would however oversize the heat exchanger, we ended up with two 150,000 btu heat exchangers in series to keep the output temps of the 4 ton geo down, but on a boiler it might not be as big of a deal if the delta T is a lot higher. Right now the output of the geo is leaving at about 20F above pool temp and returning about 10F higher than the pool water, which is fine. The problem was with a single 150,000 btu exchanger and on the hot tub that meant the geo had to put out 130F and returning at 120F to get 100F hot tub water. It never trippe out, but to close for us.

The trick will be the heating call from the pool equipment "turning on" the boiler. Since it's a pool it doesn't need to be quick, but I am not sure how those boilers turn on, is it as simple as a 24vac switch?