After waiting longer than I ought to have after noticing sometimes a gas smell outside of my condo I called the gas company to inspect.

They went to read the exhaust from the furnace (outside) then came in to turn off the gas to the furnace after that reading.

Then the guy had the thought because he had “noticed a pattern with high efficiency appliances “ to check my hot water heater exhaust (exhausts into a completely separate area) and it was also reading gas in the exhaust (again outside, no readings inside thank goodness.).

Is there some connection between these two appliances? Why might they have this problem simultaneously?

Any advice for working with the contractors I can get a hold of?

Thanks 🙏.

Edit: also, did they really have to turn it off for what was in the exhaust but not in the home? It’s 15 degrees outside and I can’t get a hvac guy until 7 am. I am generally grateful but the form they gave me was so non specific. And when I asked what the reading was in case it’s useful he said it wouldn’t be useful. Then I asked anyway (at least so I could know what they were measuring) and he said it was 10 gas. I asked if “gas” was a unit and he said… yes? Does this seem right? Now that I’m sitting in the cold hoping my pipes don’t freeze I’m wondering a little more if that should have mattered on balance. I live in a condo (basement) so thankfully I think I get enough heat around me not to worry. They shut it down around 1 am and it was 74 degrees. It’s 4:30 now and sitting steady at 67.

Question from user rfp314 at hvacadvice at reddit.com.

Answer:

Answer from user at hvacadvice at reddit.com.

why would both my furnace and my tankless hot water heater be exhausting gas