In order to have hot water, you need a boiler. Boilers are notoriously expensive both to buy and repair, so be sure you're making the right investment. Always consult an expert (a heating designer ...

I have my forced-hot water boiler and my hot water storage tank in the crawlspace and the necessary plumbing, of course. I thought about pumping in concrete (might be expensive for a 25-by-30-foot ...