Lesson learned, about winterizing using blow-out method

Well, temperatures here have started dipping down to freezing, so Saturday I had to officially end the camping season, and winterize the RV.

Anyway, I went through the usual procedure I use for winterizing - Remove water filter, run some antifreeze through/into the water pump, run air compressor to blow out all water lines, pour antifreeze down all traps/drains, etc. Have always used compressor blow-out method, and it works great for us.

Well, I'm finishing up pouring antifreeze in the bathroom shower and sink, when CO detector goes off. Cannot get it to quit alarming, sensing presense of CO in the RV. I open several windows, turn on bathroom fan, it finally quits. Turn off bathroom fan, a few minutes later it (CO detector) starts squealing AGAIN. I turn fan back on, let the fan run (with several windows open) for a good 20 minutes, CO detector then turns off, and everything is good.

At first I thought that this was a bad CO detector. Have had that happen before. However, the fact that after ventilating the RV for a while it cleared out....Well, seems there must have been CO present inside.

Oh, and no, the generator was NOT running, there was no gasoline engine running anywhere close by, no indication whatsoever of CO (and all gas appliances were turned off, gas bottles closed, shut off).

Soooo, apparently in the process of winterizing the RV, SOMEHOW, enough CO gas got in the RV to trip the detector. After thinking a bit, I realized what must have happened:

Air compressor was sitting in the garage when I was running it, when blowing out the lines. I run a long 100' air hose from compressor in the garage out to the RV when inflating the tires or winterizing. Compressor has always stayed in the garage.

I can only guess that there must have been some CO gas lingering around in the garage from when one of the cars pulled in earlier, and the compressor sucked it into its tank when running. Have been using compressor blow-out method for winterizing for years, and never had this happen before. But, makes sense how it could happen, when compressor's air intake is just a foot or so off the ground and inside the garage where the cars are.

Anyway, lesson learned from this: I think from now on when winterizing, I'm going to first purge the compressor tank of all air in it, roll it outside away from the garage, before turning it on. Hopefully that'll prevent any CO gas from getting sucked into the air compressor, and blown through the pipes and into the RV.

Has anyone that uses compressor blow-out method, ever had something like this happen? Any other ideas/theories on what may have caused the CO detector to go off in this case?

Seeking Advice

kaydeejay
Explorer
Oct 29, 2013
Not buying the compressor sucking in CO from car exhausts I'm afraid.
Modern cars do produce hardly any CO, to the extent that the hosepipe thru the car window from the exhaust in a closed garage is no longer a successful way of committing suicide.
I'm leaning to Glycol fumes myself, but have never had it happen either.
Fish__n___Grits
Explorer
Oct 29, 2013
I was standing by to move a construction barge one day, watching the divers working on the pilings under the pier. There were four divers on one compressor, which was on the pier. The Porta - Pottie guy came to pump out the toilets,and the discharge from his vacuum pump was right by the compressor intake. All four divers popped up at once and started yelling. I thought it was kind of funny, but they didn't. I guess it could have been bad if they were deep and had to come up slowly!
willald
Explorer II
Oct 29, 2013
ecoast wrote:
I'd say it's the mist from the glycol, prolly not co2

..RV antifreeze could trigger it? Hadn't ever heard that, either. If that was the case, I'd have thought this would be a common issue that would happen all the time with winterizing, and folks would be talking about it more on forums like this. This is first time its ever happened for us, and I've been doing the winterizing thing myself for over 10 years.

Think I might do a search or two..

Will
ecoast
Explorer
Oct 29, 2013
I'd say it's the mist from the glycol, prolly not co2
powderman426
Explorer
Oct 29, 2013
Get a CO alarm with a digital readout then you will know how many parts per million of concentration you have and whether its a reason to be concerned.
willald
Explorer II
Oct 29, 2013
mlts22 wrote:
One of my old habits with air compressors is to pull the ring so the tank blows itself out when done. This comes from the expensive Iwata compressors that are used in airbrush makeup work. Very precise machinery, but they do need to have the tanks emptied after a work session so there is no chance of water getting in the tank (there are water traps, but even then, any water going out the end severely screws up an airbrush job.)

Yes, every now and then, I pull the ring and drain out the compressor tank of all its air (mostly I do it 'cause the loud hissing noise it makes is a fun way to scare the cr*p out of some stray cats that hang around our house, haha!!)

Apparently, I need to pull that ring and purge the tank out more often.

Will
willald
Explorer II
Oct 29, 2013
Homer wrote:
in 40 years never had this happen. I agree with your deduction, unless your dog was in the coach with you. I will say one thing about your CO detector, it must be ultra sensitive. Again the dog could set it off, I have heard of lots of people finding that to be their problem.

Wow, a dog tripping the CO detector?? Never heard of that one.

No, we don't have a dog, I was only one in the RV when this happened. Can't blame this one on a dog. :)

We had a CO detector go bad about a year ago. It just started going off all the time, for no reason (and of COURSE, it started doing it at 3am when we were out camping, haha!). Had it replaced under warranty (very glad it was under warranty, them things ain't cheap!!) Ever since then, when that thing goes off, I immediately suspect the detector itself is faulty. That weren't the case this time, the detector was doing exactly what its supposed to do (and I'm glad it did).

Will
mlts22
Explorer
Oct 29, 2013
One of my old habits with air compressors is to pull the ring so the tank blows itself out when done. This comes from the expensive Iwata compressors that are used in airbrush makeup work. Very precise machinery, but they do need to have the tanks emptied after a work session so there is no chance of water getting in the tank (there are water traps, but even then, any water going out the end severely screws up an airbrush job.)

I can easily see that happening though. It can be easy to position an air compressor near a generator's exhaust.
old_guy
Explorer
Oct 29, 2013
this happened tome the other day, only mine is more confusing then yours. my compressor sits in a storage room not the garage and I also ran 100 ft of hose and was sitting in the chair trying to think of what next to do and the alarm went off. got it off and a few minutes later it went off again. it finally settled down and I have no idea why it went off.
Vulcaneer
Explorer
Oct 29, 2013
Interesting theory. I do understand, that CO could enter in through the intake into your compressor tank, as you describe. And when blowing out the lines, could go from compressor tank and out the faucets into the RV. If the CO did enter in to your compressor tank it would be....well....COMPRESSED. And as such might be quite CONCENTRATED. So blowing a little through the lines might actually be blowing a high concentration through the lines. The thing that impresses me is that you could figure that out. I never would have thought that through. Good job.

But because of the high concentration coming in to your trailer, I would not think your CO detector is OVERLY sensitive. Probably working just fine. And good thing it is too. So I would not worry about the CO detector.