Propane Leak Detection or Theft?

The remodel of our casa included a new propane tank and associated plumbing. None of the original plumbing was kept. After two months, I found the tank to be nearly empty! I had figured, generously, we had a six-month supply. I witnessed the initial filling watching the meter on the truck. I do not doubt that the tank was filled.

Our plumber who did the install could only find a pinpoint leak in a hose connected to the dryer.

Likely there's a broken pipe in an exterior wall or the roof, and it's venting away. Not once did my wife or I pause and say, "Do you smell propane?".

Two questions:

1) Know of anyone who has a gas sniffer that could examine the entire house?
2) Is theft a possibility? The tank is up in the mirador and fed from a high, street-level connector.

Thanks for your feedback!

I highly doubt theft too. Sounds like a leak. I would seek the opinion of a different plumber/gas guy.

They make gas detection meters - I borrowed one from a neighbor when I had a gas leak in a new construction condo done by poorly paid/unskilled laborers.. Turned out a majority of the units had gas leaks in the walls = saving money by piecing lengths of copper together, rather than buying the whole length needed. Lame-ass seals don't last. Once in the wall ~ SOL. I personally would check around the hot water heater installation for seal leaks.. ALL connector cords need to be METAL, not plastic too  - just experienced this foolishness last week myself.

You need to have a gas meter installed. I have one from my tank to inside my kitchen. Anytime I have gas delivered, I can actually see how much is put in the tank and at anytime I can check how much gas is in tank. May not help with present problem but will help in future. Remember full tank is usually around 80% as a fuller tank can cause explosion.

Here is a benchmark:  I have a 295 litre propane tank which is filled to 85% and refilled when it falls to 20%.  I burn through this range (65% = 192 litres) in about 4.5 months.  About 99% of the propane is used in cooking; LOTS of cooking!  My house has solar electric/water.