Need a little help. I have a Heatmor Outdoor wood stove. It is rated to heat up to 10,000 square feet. My house is about 4400 square feet. I have two 80 gallon hot water heaters and two furnaces. I installed my sidearm heat exchangers to my hot water heater by removing the drain valve and using a tee. I reinstalled the drain valve on the end of the tee and piped up from the tee to where the temperature relief valve. The temperature valve is on the side of the hot water heater. I removed it and installed a tee. I reinstalled the valve on the end of the tee and piped down into my sidearm. So my sidearms are in between the drain valve and Temaperature relief valve towards the top of the hot water heater. I have two supply lines coming from my stove and two return lines going back to the stove. One supply line goes to one hot water heater and furnace and the other line goes to the other. I have circulating pumps operating each supply/return line seperately. My supply lines come in the house and go into the sidearm then they go to the heat exchanger for the furnace and back to the stove. The problem I am having is with my sidearms. They heat my water for a couple days then my water starts getting cooler until it gets cold. Water from the stove is flowing threw the sidearms and to the heat exchangers for the furnace because the house heats great. Its seems that when I open the temperature relief valve and fill a bucket of water up the sidearm starts working and the water heats up. Then in a couple days the water started getting cooler again. Any help would be great. Thanks