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Carbon monoxide alarm

R

Ron B.

Well Known Member
I'm getting an intermittent alarm signal on my new RV with a CO Guardian 353 detector. If I use cabin air it self clears , it I use cabin heat it self clears. Without air it will stay on. I only have 7.4 hrs. so far, I doubt it's the new aircraft smell causing this. I thought I did a good job sealing the firewall and after sealing the firewall I added Fiberfax along with S.S. foil and sealed all that. As I wright this I'm recalling that I did not seal around an eyeball cable pass thru. I will get to that before next flight , but I'm doubting that will solve the problem ( I hope it will).
Anyone else run across an alarm in a new aircraft? I could not find any threads on this topic.
Thanks Ron
 
Do a light test.

In a very dark hangar (at night if necessary) have a helper move a very bright light across the entire area of the firewall while watching for any hint of light on the aft side.
If you see any light at all, you have found a potential leak point.
 
rvbuilder2002 said:
Do a light test.

In a very dark hangar (at night if necessary) have a helper move a very bright light across the entire area of the firewall while watching for any hint of light on the aft side.
If you see any light at all, you have found a potential leak point.
Click to expand...

Thanks , I'll do that.
 
Also, be aware of the "tail pumping" phenomenon whereby air can enter from the high pressure area in the tail area and travel through the fuse to the cockpit where there is lower outside pressure over the canopy. Not sure if this will be a problem for the -14 but it has been in some of the others, like my RV-6. Solution was sealing the baggage bulkhead to prevent air from getting through the bulkhead. I was getting pretty consistent CO warnings until I fixed it.
 
If all else fails, call Ash at Guardian - he is a wealth of knowledge. I have one of his units with zero alarms in my -10.
 
We never had any alarms on our 10 either, but I think we had Flightline's interior covering up the rear bulkhead. Might not have been tight but might have made the difference.
Thanks for the tips.
 
Sealed the baggage bulkhead best I could and sealed the cable ball penetration, thought I had it made as the alarm never sounded in the first two hrs. today. But this evening it went off a couple times. I would clear it with opening the fresh air vents wide open for a minute. The bulkhead below the baggage floor is full of lightning holes and the air can flow forward and come out numerous places.
 
There is exhaust air entering somewhere, very likely from the aft portion of the airframe. Opening the vent or even cabin heat adds a little pressure to the fuse so you have air going out the hole that is sucking in exhaust when the vent is closed. Maybe you could tie/tape some pieces of yarn around the cabin to see which one blow forward with the vent off and back with the vent open and see if you can seal those openings. I have seen exactly this same scenario with a poorly sealed A/C system in the tailcone of a -10. Opening any vent shut off the CO Guardian alarm.
 
Ron, I had to also seal up a couple of canopy leaks when I sealed the baggage bulkhead. Just wondering if you've checked that. I think the slider is probably more prone to leaks than the tip-up, so probably not a factor for you, but worth checking. I took a small piece of cloth and moved it around the canopy edges in flight to see if I could detect any suction. If you find any, you need to seal them up. I think you're on the right track. With me, I would get CO indications at different airspeeds, mostly when I would slow down. Happy hunting. :)
 
No cover on my bulkhead, never open the fresh air vents (a/c) and never receive an alarm on the -10. Did you call Ash yet?
 
Just because no one has stated it yet....
You need to ventilate your cockpit or not fly until this is resolved. Your CO alarm it telling you something important. CO can kill you!
 
Pat Hatch said:
Ron, I had to also seal up a couple of canopy leaks when I sealed the baggage bulkhead. Just wondering if you've checked that. I think the slider is probably more prone to leaks than the tip-up, so probably not a factor for you, but worth checking. I took a small piece of cloth and moved it around the canopy edges in flight to see if I could detect any suction. If you find any, you need to seal them up. I think you're on the right track. With me, I would get CO indications at different airspeeds, mostly when I would slow down. Happy hunting. :)
Click to expand...

I would also say my problem is at slower speed settings (been breaking in the engine). Will check the canopy seals. Thanks Ron
 
Gisnar said:
Just because no one has stated it yet....
You need to ventilate your cockpit or not fly until this is resolved. Your CO alarm it telling you something important. CO can kill you!
Click to expand...

I always clear the air when the alarm sounds, it does not take long.
Thanks
 
Evolution10 said:
No cover on my bulkhead, never open the fresh air vents (a/c) and never receive an alarm on the -10. Did you call Ash yet?
Click to expand...

Not yet , but will if I cannot resolve the issue with help from here. So far I have received good tips here. Thanks for the suggestion, Ron
 
Find it----fix it.

Ron B. said:
I always clear the air when the alarm sounds, it does not take long.
Thanks
Click to expand...

One thing to keep in mind is that your body does not purge the CO very well, it will accumulate over multiple exposures in a short time------like a single flight.

The alarm will "reset" after you give it a blast of fresh air-------but your body does not.

CO is dangerous stuff------there is a reason we put these alarms in, please do not take this alarm lightly.
 
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Mike S said:
One thing to keep in mind is that your body does not purge the CO very well, it will accumulate over multiple exposures in a short time------like a single flight.

The alarm will "reset" after you give it a blast of fresh air-------but your body does not.

CO is dangerous stuff------there is a reason we put these alarms in, please do not take this alarm lightly.
Click to expand...

I look for the problem every flight. I plug a hole here ,I plug a hole there. Today I think I might have located the culprit . While cleaning the oil (yes I do have a little oil, I'll solve that one soon) from the belly ,I saw that I did not plug the ADSB antenna holes (no antenna ADSB) yet. I placed alum. foil tape over the hole and could not get the CO detector to sound off at any speed and with the fresh air vents closed for as long as I could stand it (hot).
I will continue to monitor the situation , but hopefully I got it. I feel I did a very good job sealing the firewall taking my time and then I installed fiberfax and S.S. foil on top and carefully sealed that.
 
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