I've been having this recurring issue with water in my natural gas lines. Here are the facts:
-The apartment has 2 gas appliances- a 22,000 btu wall furnace heater (rinnai) and a gas range. These were unused for about 2 years until I bought the building and moved into this unit. The gas was pressure tested and worked fine for about 2 months until it started to get colder.
-One day the gas to the heater went out (gas range always continued to work fine). It was found that a substantial amount of water was clogging the pipes. We blew it out and thought we were good until it happened again 2 weeks later. The water was blown out and then 2 days later it happened again (this time the water was frozen in the pipes)!
-Now the gas company saw water was in the meter, and given the amount decided to check the main. After digging up the road they did not find enough water in the main to conclude that was the problem, but they did find a leak in the valve in the underground service line in my front yard. After that was fixed we thought would finally be ok.
-Another 2 weeks go by and the pipes filled up again! Now the gas company is saying that I need to reconfigure my gas pipes before they will go any further with the issue. My gas pipe (black iron) goes across the basement and then outside, up the side of the house where it enters into the heater. Even though the pipes had been like this for many years with no issues, and pipes are outside of buildings all over the place (up here in Portland, ME), they (Unitil) are claiming a condensation issue. I will also note that we added a drip leg the day they dug up the main, which was completely filled in the most recent instance of the issue.
-Given the amount of water that has been collecting each 2 week period this has occurred, and the fact that exterior pipes are common, I really don't think I should have to re-pipe my heater. I'd be happy to do it if it was clearly the problem, but since no one at the gas company really knows I'm hoping some people in this community can provide some help. It seems to me like my natural gas has way too much moisture in it and gas company should be testing that. THANK YOU!!!!!!!