Tell me about it! I am faced with an analogous situation at the moment. There is a 500 liter propane tank on my roof that feeds gas to the two top floors for cooking and hot water. The gas lines are half-inch copper tubing, embedded in the walls and floors when the house was constructed. With every gas-fired appliance in the top two floors shut down including pilot lights, we were losing 25 liters of propane per day. Yes, 25 liters! The really scary part is, we have no idea where it went.

No amount of careful sniffing or checking every room in all four stories of he house, particularly the two bottom floors because propane is heavier than air, has revealed any hint of leakage or accumulation. All we know for certain is that more than 700 liters of propane are unaccounted for. Of course we have now turned off the valve on the tank itself so nothing more is leaking, and the pressure regulator on the tank is now completely quiet.

Clearly we are not going to start tearing out concrete walls and floors looking for a leaking copper tube. Instead, we will drop a new tube on the outside down to the level of the fourth floor kitchen, drill a hole through the wall to get into the house, and run the new pipe behind the dishwasher, the sink, and the cabinetry to connect to the stove.

The hot water heater for the fourth floor is up on the roof next to the propane tank, and that 15 feet of line has been checked thoroughly and is not leaking.

For the third floor we will just install a new system from scratch: storage tank and lines to the existing hot water heater and stove. Basement and ground-level floors already have their own system which does not at present have problems.

Presently the woman who occupies the third floor is out of the country, so she is not suffering the lack of hot water or cooking equipment, but she is returning in about three weeks so we have a deadline.

Coincidentally with discovery of the gas leak, we installed a solar hot water heater for the 4th floor. I am extremely impressed with it. With a 130 liter storage tank, it provides hotter water than the gas-fired heater, and more of it. Mid November, temperatures during the day in the high 70's, at night in the 60's (F), even before the sun comes up in the morning water temperature is 150+ degrees. Even without the gas leak, it will pay for itself in about a year and a half.

tanstaafl.