10k for a new heater sounds high i payed 3800 a few years ago and im in a big city

I was about to say just let it be till I read the baby part

I personally would want to make sure everything is safe before the baby comes

There are dates on heaters I believe so you can see how old it is and you have time to get multiple quotes

"Any thoughts on what it could be?"

Gas companies add trace amounts of chemicals to gas to enable humans to smell leaks. Typically, sulfur-containing compounds called mercaptans are added. Most people describe the smell as "rotten eggs" or "rotten cabbage." The same smell can be produced by decaying matter. If your home is on a crawl space and you have duct work in the crawl space, your system can pull odors from decaying matter in the crawl space into your home. Grab a flashlight and inspect for mold/mildew or anything that might be decaying in the crawl and cause an objectionable odor. And inspect inside the ductwork to the extent you can. A dead mouse in a duct is a terrible thing.

Oh my gosh the magic 8 ball is back!

If the gas company hasn't found it after 5 attempts chances are slim keyboard jockeys will find it. For what it's worth to you I've been called countless times to find sources of "gas odor" in all electric buildings. Depending on which occupant I asked they described it as smelling like natural gas, carbon monoxide ,something burning, electrical fire,something dead ect ect ect.

To clarify… the current heater is about 15 years old.

The smell is rotten eggs and smells exactly like the times I DID call and there WERE confirmed gas leaks (in other parts of the house at different times or our previous house).

Natalie G,

Gas leaks do happen from time to time, but calling gas company usually will get the gas turned off and directed to HVAC contractor / plumber to investigate in person. (usually if I get a call in which gas company was called the gas was merely shut off the furnace is red tagged)

A 15 year old furnace isn't really considered that old. Most furnaces come with a 20 year heat exchanger warranty / some more recent furnaces may have a life time warranty on the heat exchanger. ( if you call a free estimate service, they will probably say otherwise because they make more money selling you a new furnace )

These things really need to be checked by a licensed contractor(s) in your area, as there could also be an appliance leak of some kind (gas stove, gas dryer, water heater, furnace)

Also realize it's not uncommon to get trace amounts of gas when appliances shut off (especially the furnace) if the blower compartment is not properly sealed it can draw this trace gas into blower compartment then disperse it thru the house.

If the furnace is short cycling, this particular problem is magnified. This comment isn't to suggest this is what is happening as it could be more sinister than that. But taking this sort of thing to a comment board is just argumentative without facts.

I service the Katy, Texas area.