Got delayed leaving Montana and am now having to run off the hurricane heater and on board water. Over night I lost hot water. Checked everything for possible frozen pipes (got below 0) last night and found no evidence of frozen pipes. In fact the bay which has the hurricane and seaward hot water heater is very warm. The storage bays are also very warm and the water bay is also very warm. Seems the hurricane plus one space heater down below is doing a great job. I have cold water at every faucet but no hot at any faucet. In the bay with the hurricane there are two pumps. One, I am certain, pumps the fluid through the several hydronic heaters. What is the other pump for. I am not hooked up to city water.