Carbon Monoxide Alarm and Bleach Fumes

[pushx]

A while back I had a new hot water heater installed to replace the original possibly 30 year old model. Due to ‘life happening’ I’ve been unable to RV it up until recently. I’ve been preparing for a trip, and felt that I should sanitize the fresh water tank. I went ahead and drained the tank and hot water heater, and pumped about a third of a gallon of bleach into the tank and filled it up. I then went ahead and turned on the hot water heater for the first time since it was repaired.

I pump some bleachy water through the sink and all of a sudden the carbon monoxide alarm goes off, and I can’t get it to stop. I pull out my gas leak detector (this thing here: https://www.homedepot.com/p/HOME-FLEX-E ... /301876827) and put it by the bleachy faucet and I can’t get it to go off. I put it over on top of the hot water heater and it goes off consistently. I’ll see if I can get a video together to show the exact location but its right by the external port, on top of the heater, but inside the rv.

So I’m pretty worried about this. But is it just bleach fumes? Is it ok to put bleachy water through my hot water heater like this? Most likely calling the mechanic tomorrow.

[Rokrover]

Simple carbon monoxide or propane gas detectors can be activated when exposed to a variety of chemicals other than their target molecule. Examples are listed in the owners manuals available online. Chlorine bleach can release a trigger gas at ppm levels sufficient to cause a false alarm after contacting another reactive material like the sacrificial anode inside your hot water tank. I wouldn’t worry; just be sure to flush out all the bleach with fresh water and air out the coach. Any suspect vapors will evaporate below the alarm threshold now you are enjoying 100+ weather in Tucson

[BobW9]

The propane line to the hot water heater is inside on the right of the heater just about at the wall. It is a copper tube that comes up out of the floor and attaches to the heater with a large nut.

You should get thick soapy water (dish detergent), or better yet, the real micro-leak detector stuff like Cal-Blue Plus from Nu-Calgon (it is just extra thick blue liquid) and apply it all around the nut. Then wait 5 minutes or more to see if any bubbles form. If even a single bubble forms, then you have a slow leak of gas. The reason the Cal-Blue Plus type stuff might be better is, I believe, it is supposed to be thicker and last longer, so you can see very slow leaks that have a single bubble over minutes, rather than soapy water that might find bubbles over the first minute or two only.

If you have a leak, you need to shut off the propane at the main propane tank, undo that nut, and then reseal it, maybe adding a bit more pipe thread sealant, like Tplus2 from RectorSeal. You want to make sure the sealant is certified for LP gas propane on copper pipes, as some of the usual sealants like ProDope may not be good for Propane. I have ProDope for the pipes in the house, but it states in fine print that it is not recommended for LP Gas. Then turn the propane back on again and apply more of the soapy stuff to see if you still have any bubbles.

Or take it back to your RV guys

Bob

[Blue~Go]

I have had detectors go off for numerous other reasons. In my case the propane detector on the boat used to go off when filling with diesel sometimes. Or when spraying certain cleaning supplies. They don't always seem to know exactly which "problem" is occurring. Thing is, a third of a gallon of bleach is a pretty large amount, so there would have been a lot of fumes. (That's like 7 cups and usually you use about a quarter cup for 15 gallons of water to sanitize.)

If you used a gas leak detector (presumably gas means propane), and didn't smell propane (and it was the CO detector that went off anyway, not the propane detector, right?), then it's probably not propane. Still, as Bob mentions, it's never a bad idea to check the fittings of the propane lines with fluid meant for the purpose or soap-bubbly water. I actually just did all mine yesterday because I (finally) cut down the old refrigerator line and re-capped it. So I checked that new flare, and then went around and checked all the other ones. Nicely, Chinook set it up the way it's supposed to be with NO propane line joints inside the coach (except obviously there has to be a joint where the line joins the appliance), so there is one line for each appliance and that's it.

Although I hesitate to contradict Bob, who clearly knows his stuff, I don't believe you are supposed to use sealant on flare fittings* (which all of our propane lines are). If it's not sealing, the flare may be deformed or poorly made (unlikely if it's lasted this long), or it may need just a wee bit of a tighten (13/16" wrench on the flare, plus whatever wrench fits the opposite side because you can't just tighten the flare without holding the other side or you can break something). But I bet it was the bleach.

I would flush REALLY well, because I don't know if that much bleach will be hard on anything. My guess would also be that the bleach fumes set off the detector wrongly, but this isn't a bad time to check over your propane joint(s) and your detectors. Like, are you still using the built in CO detector from Chinook? They have something like a five year life, and it's in a bad location anyway (CO drifts, vs. rising or sinking, so the detector is usually recommended to be at head height when sleeping - who sleeps with their head at the ceiling by the door?). I would recommend a battery powered detector with a digital display and put it in a better spot. IMO this is one place where hard-wired is not quite as good.

BG

*I imagine it's sometimes used by contractors in a pinch, but it's not really meant to be used on flare fittings is what I understand. I've never had one not seal that didn't have some structural problem (bad flare, etc). Or something like a crack in the tubing where someone made a bad bend or other "structural" issue. Copper flares should seal just with the flare, the male part on the fitting or appliance, and the flare nut.

[pushx]

So....oops! I guess I used too much bleach. Good thing to note for next time! This is my first RV and first time doing this, so learning lesson! I'll run a lot of water through it.

So yes, this was the Carbon Monoxide Alarm going off, not the LP alarm. Further attempts to get the leak detector to go off have failed! It seems very likely that the issue was the bleach, not the hot water heater leaking LP. I ran the hot water heater for a good bit, with the detector on it in the same place it was before. It didn't find anything noxious.

Thanks Bob for the gas line troubleshooting tips. I may need to do this at some point, so good to know. When it comes to gas, I might just take it back to my rv guys!

[BobW9]

Hey, Blue. I make as many mistakes as anyone, and defy anyone that knows me well to say otherwise! I have not yet needed to perform any propane-related work on the RV and hadn't really noticed they are flare fittings. I believe you're right, for flare you do not use sealant.

I had jumped to looking at the propane connection simply because I understand the water heater to have been replaced and never run. And then when testing for the alarm, Pushx stated his Gas Leak Detector went off when near the water heater but not the faucet. I guess that detector catches chlorine fumes as well as propane, which maybe were just settling to the floor in the coach.

All's well that ends well, eh?

[Blue~Go]

Bob, Thanks for being gracious. But as it turns out, I made a mistake too. I thought the specialized gas detector didn't go off, but as you pointed out it did. None of us are infallible I guess (hmmph).

Anyway, dollars to doughnuts it was still the bleach fumes.

BUT, since you did just have the water heater replaced (which means they un-did and re-did the flare nut on the connection), I would just check that one fitting for propane leakage. It's on the forward side of the water heater, between the heater and the driver's seat, near the outer wall. The line comes up through the floor, then goes outboard and attaches at the water heater. You will see an elongated, sort of cone-shaped copper "nut" just at the heater. Mix up some soapy-bubbly water and lay some on around the joint (with the propane valve turned on, but water heater does not need to be running). You may want to use a mirror to see the back side. If there is a leak you will get a slow but continuous bubble in one spot. With soapy water you will also just get the bubbles naturally popping, but I think you'll be able to tell if one specific location still has bubbles continually coming up and popping. (They also make specialized goop you can use.)

IF you get a small wizzle, you can just tighten the flare a wee bit more. The way I like to do just a little movement like that is to put the two spanners on so they are about an inch or so apart at the far ends, and then you can just "controlledly" squeeze them together and it will tighten a little bit without going hog wild. That usually solves a little leak. (In fact, I usually err on the less tight side at first, because I'd rather tighten a little more than over-tighten at first.)

But it was probably your bleach factory..... Are the overhead cabinets lighter colored now?

BG

PS: I just noticed you have an '89, so the exact details on the water heater copper line location may not apply, but the concept should hold true.

[pushx]

So here is a video of me looking at the flare and searching for a leak, to give you guys an idea of what I'm seeing:

https://www.youtube.com/watch?v=72qThQf1Pp8

Thanks guys for the help, I really appreciate it. A lot of this is new to me. But thankfully I like tooling around with this kind of stuff.

Video summary: I don't see any bubbling at the flare using the soapy water. I hope I'm looking at the right connector. I'm also not seeing the gas detector going off at the original location. At the end I follow the copper tube outside to see where it goes and to give a view of the system from the outside. I mention a second flaring but it was just a grommet for the exterior hole for the intake tube.

[pushx]

But it was probably your bleach factory..... Are the overhead cabinets lighter colored now?

Haha, what is it with the 80s and dark wood? I think it would be an improvement!

[Blue~Go]

And since we are talking RV "decor" and not houses, the 80's extend all the way into the late 90's and even the 2000's! The mauve upholstery and tile go away, but my '99 had plenty of slate blue velvety stuff, and fairly dark wood (that went bye-bye). Never thought of your method though, I removed mine the hard way

So just in watching the beginning of your video (great idea to post that), I see a couple of things.

1) There is an "extra" gas connection that doesn't exist in the later Chinooks (including mine). That IS a flare nut you are looking at, and it does not seem to be leaking. However, there will be another one where the copper line continues on and actually attaches to the water heater (unless it's *really* different, but I've never seen a water heater come with 12" of copper line attached).

Did they add that line? Reason I ask is that on my Chinook they used long flares (which is recommended for vibration on vehicles) and those are short flares. Plus it looks like a double flare with a short male/male piece in between. BTW, where they would leak is not where the "back" of the flare and the tubing meet, but where the "front" (bigger end) of the flare meets the threads (of course check it all for good measure).

Here is an illustration of a flare fitting, for reference. You can see why they call it a flare: The end of the copper tubing is flared. (After you put the flare nut on... ahem... don't ask me how I know.) Then the next fitting has a formed cone (and threads). You slide the flare nut over a piece of tubing, flare the end of that piece, then set the "cone" of the fitting from the piece you are joining (you have to buy cone fittings, not make them), and then slide the flare nut down and screw it onto the threads (which is where you usually get any little leak, although of course it CAN leak from other places).

You can ignore the threads on the far right - they aren't flare threads and ... well, just ignore them.




Edit for this next part: I watched the end of the video and I see you did go outside and take off the grille. That would normally be the only fitting (besides the lines under the Chinook). At least on later models. So you could just check that one for leaks too. (And kind of ignore my not realizing you had already seen this when I blather on below.) BTW that large "nut" in the very center bottom that is right at the end of the video when it goes still is the drain plug/anode rod for the water heater. It does look just like a Suburban 6 gallon.

On mine (Suburban 6 gallon), you can see that final flare by taking the grille of the outside wall of the rig (in other words you are standing outside). It's right down in the forward/lower corner on mine. Let me see if I can dig up a pic. (That gas would technically leak outside, or should because that outside "pan" area should be sealed from the interior, but of course you'll still want to check it.)

Okay, I'll look for a photo.

So here is a photo of the outside "pan" area of a Suburban 6 gallon. I mis-remembered and the flare is on the forward side but midway up, not at the bottom. The whole area that you see in the photo is what you see when you are standing outside and remove the access panel on the water heater.

You can see the area where the copper comes into the exterior "pan" of the water heater through a black grommet that is also sealed (with silicone, but we'll ignore that ). On my era Chinook that copper line comes up through the floor about a foot in from the wall (by the front of the couch), then travels more-or-less horizontally over along the floor to where it goes into that hole and outside into the pan. There is no extra "vertical" copper or set of two flares inside like I see in your video (that's actually completely improper on a boat, but somewhat acceptable in an RV as long as it's secured and it's in an area you can check from time to time - vs. my buddy's other brand RV where they buried many flare fittings inside the walls in inaccessible areas - boo!) Did that second flare and extra copper just get added at the shop for some reason? Maybe you don't have a Suburban so it's different?

This is not my Chinook by the way, nor did I annotate the control buttons. But it shows the propane line and the flare fitting really well.

Okay, off to finish watching the video.

BG