First off - thanks to all of the professionals who are sharing their knowledge of Apollo systems. I have (2) Apollo 5010 units supplying heat and hot water for my townhome. One of the units will lose it's pilot light for no apparent reason. In the last month and a half it has gone out twice. The last time it was relit it remained so for about (2) weeks. Any suggestions for what may be happening? The only reason it is known is because heating and water are both affected if only half of the system is operating. Thanks