Our heater is leaking. We took the cover off and inspected the heat exchanger. There is no leak at the top. We haven't taken it entirely out of the heater yet. My question is, can we still use the heater if it is leaking? We are not going to replace that heat exchanger. The part is just too darn expensive. We thought we had a plan. We were just going to run the heater long enough to get the pool heated and then flip the valves and shut the water off from going through that heater. We ran into a problem when we try to do this. They heater will kick on for about 15 seconds and then it shuts off. I'm assuming that there is not enough water pressure going through the heat exchanger? We had the part replaced before. When it was leaking that time the water leakage was very visible. Like I said earlier, we can't even see leak at the top. It also takes about five or 10 minutes before you even see the water coming out of the bottom of the heater. Could this be a separate problem? Or is it all caused by the leaking heat exchanger?