It looks to me like in a previous hot water heater insta , they moved connections and were too lazy or unskilled to patch the drywall and just used those to cover the holes.

You can patch the holes properly yourself easily.

Trying to make sense of why someone would go to the trouble of putting floor drain covers over these holes, which is much harder than getting a solid coverplate. It's like they wanted air transfer. Sometimes, people aren't sure why of things, but know they don't want to mess too much with it, so kind of wind up with a half-arse solution.

Also, the location of high and low does not fit moving a gas line and Bvent over 4". And the ceiling cover looks to be protruding, like it is attached to a duct or something not fitting flush.

What I would guess is it was originally your fresh air for combustion, ventilation, and dilution for the gas-fired water heater. You are required a certain amount based on the BTU's of the appliance, for your safety. It could not take air from the garage (but ducted outside), and if there's a floor above instead of an attic that would be strange (but ducted somewhere outside), but it makes the most sense in some configuration.

I have no idea why either but originally we thought it was an air vent for the hot water heater or something similar but we’ve found nothing when we researched it.The hole in the ceiling goes straight to the attic and it wasn’t attatched to anything. I could see the Whirley bird on the roof from the hole when I was taking the picture.
I know a precious owner did some diy remodeling before we bought it so we’re guessing they moved the hot water heater a few inches for some reason. Wish I could see what all was done to this house since it was originally built. We have a closet addition also that is so hot I hate going in it to get my cloths. So many bad diy projects done here.

My guess is that these were intended to be outside makeup air sources for the water heater - both the combustion air and the air at the draft hood. Just a guess

@JANE HESTER

Where is this located? Is it in an otherwise sealed room?

I'm pretty sure those are intended to be outside makeup air - and if the room doesn't have another air source, you may be making a mistake closing them up.

It’s in the garage.

I’m not sure what you mean? Would they have that in the garage? I’ve never seen this before in any house I’ve ever lived in with a garage.

Now I’m kind of nervous that I messed up by covering them. 😬

Ok, so this is actually a picture inside the garage, not a laundry/utility room. The wood casing and popcorn ceiling was a non-typical choice by the previous owner, unless this space is being used as living space instead, which if it were, would continue the necessity of having combustion, ventilation, and dilution air for the gas-fired water heater (and furnace if that is there too).

If this is a new house to you, hopefully an escrow inspection raised some points. I don't want to cause concern for you, your house will not fall down, but I am going to point out what I observe just from the picture so you have information to decide what, if any, action you take in the future or look into further.

- "Vents": A solution to providing necessary outside air for a gas-fired appliance within an interior room can be chosen to have a high+low "vent," when the room is too small to provide enough indoor air. However, these would be undersized, and the choice of floor drain cover instead of a grille limits the air flow. And having this in the garage doesn't make sense, especially with the low vent going inside to the Mudroom/laundry/whatever. There is a code requiring a means of eliminating fumes or gasses in areas where they can be processed (e.g. garage), so maybe these, looking to be 3" round holes, may have once been connected to a jerry-rigged exhaust fan or something for some reason.

- "Venting" in garage: A garage wall shared with the house cannot have an unprotected opening into the house, so the low vent cannot be open. The high vent would have to be ducted to an exterior wall or something, if the attic is continuously open across the house from garage.

- Door: The door for a garage wall shared with the house cannot have a window (unless it is fire-rated, which you would see a thick frame and metal wire in the glass). It must have a threshold and seal around the door, the same as your front door. If there is a step down to the garage, the door cannot swing out over the step. It would need a self-closing hinge, which yours do not look like.

- Water heater: AO Smith is a good manufacturer, so good there. The gas line looks to be bent too sharp exiting the valve at the wall. A longer line (like 48" or 60") would help to not only alleviate that but push it back in a little so nothing gets snagged or hung on it. If your ladder and table storage is leaned against the water heater's control valve/thermostat unit, it would be better to store them somewhere else so as not to hit the gas line or pry the unit if stuck. The top line water connections are not how I would typically see them, and a city inspector might have issue. Also, based on everything else, even though it can't be seen in the photo an assumption might be right to say that the T&P valve is not piped correctly, Because your WH is on a stand (required 18" high in garage), the pipe would need to go past that to floor or be piped somewhere else.

Thanks for all this info. I’m about to go check the inspection and see what it says about this or if I can find any info in there. I didn’t know garage doors to interior shouldn’t have windows. Interesting. One of the previous owners moved a lot of stuff around in the kitchen area (which that garage door with the window opens to a small hallway type area/laundry room to the left and then another door about 2 feet away from the window door to the kitchen) because alot of that also does not make since. If I can add more pics I will gladly do it to get your opinion on what you think about it. Do you know if it’s possible to get original floor plans from when a house was built? I would love to know what all was done and I’m sure that would answer all of my questions about it.

If you think you have some creative previous DIY, you should see mine.

This weekend i went to pit in a 30 amp dryer outlet figuring with 20 places used in a 30 breaker load box, it would be easy. i took off the inner panel and the guy used a 30 breaker cover on 20 breaker load box. That made a simple wiring job 10 times harder then it should have been.

That actually sounds like something that happened at my moms house recently. I don’t even know how to explain it cause i know absolutely nothing about it but it sounds very familiar. Always seems we get screwed when hiring contractors for anything around here cause we’re women. I’ve tried to find decent help by asking people who they recommend but it still never seems to work out. That’s why I’m attempting stuff myself here.

I am not surprised

My girlfriend has this house and its shocking how many times people have tried to take advantage of her

This winter the oil company supposedly gilled her tank with 210 gallons of oil. i looked on the slip and the guy was here for 1 minute

i called up and asked them how many gallons a minute their trucks could pump?

I got a lot of money taken off the bill for that catch

@3onthetree

I'm not suggesting that the attempt at makeup air - if that's what this is - was done properly, but I do think that's what this is. It may be undersized and some "creative" covers, but it fits with a high and low vent that vents to the outside (attic space for the high vent).

I don't know if it's necessary because of a sealed room, or if there is an exhaust fan, clothes dryer, or similar devices that might necessitate makeup air for the water heater. Or maybe it wasn't necessary at all and the previous owner did it anyway.

What doesn't make sense is that these were abandoned holes where the water heater had been moved.

@JANE HESTER Can you provide a photo of the top of the water heater. I would like to see if there's any evidence of backdraft around the hood.

@Jake The Wonderdog, I never ruled out that they weren't used for some reason of getting, circulating, or exhausting of air, that is Stax riling you up.

Stax doesn't rile me up - I just ignore him.

You were talking about how it's undersized, in a garage, etc. and because of that, I took it that perhaps you didn't think that's what it was.

I think it is makeup air and was just poorly done - and who knows if it's needed or not without looking at the entire setup.

Perhaps I misunderstood your response.

I will get a picture as soon as I get home. With a few other pics of questions about odd things I would like yalls opinions on too. Thanks so much for y’all taking the time helping me. It’s much appreciated.

Sorry it took me so long but I have pics. Not sure if I got the right pics so just let me know. Also I know the ladder is on top of the water heater I’ve asked my boyfriend to move them numerous times and he claims they are fine. I don’t want to mess with them and accidentally knock something and blow up. Lol I hate messing with anything gas.

Nice job patching it.

Thanks. I thought so too for my first time doing that. The ceiling one not so much but I’m not done with that one just yet. I had to mix my own color cause the original color paint can had dried out from the previous owner and I threw it away when we moved In. I used chalk paint too! Good enough for the garage!