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CO/LP detector false alarms

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My Safe-T-Alert CO/LP detector started false alarming about the same time that the allergy season hit in southern Arizona.

I ordered up a new co/lp detector (manufacture date: Dec 2015) and got it installed yesterday afternoon.

 

At 1:11 am the alarm goes off (just like the previous detector).

The weather is warm and the windows have been open all day and night. I'm on shore power and no propane or other combustion products are used.

 

I reset the alarm, back to bed. . .2.5 hours later and it alarms again.

I reset it. 3 hours later, alarms again.

So I put a soft pillow over it and it works fine. :rolleyes:

 

There's no odor of propane, and all the windows open.

 

I'm wondering if there might be a correlation between pollen detection and temperature.

I question temperature because the detector alarms at night, when the temperature drops 20 degrees.

 

There's a Mesquite tree right outside the window and several other Mesquite trees on the property - just now going to flower.

 

Any thoughts?

 

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Rich, we have seen a similar situation, and have nothing explanation or solution wise to offer. Most puzzling. I am going to track on this...

 

Seems like when we are boondocking in Nebraska in the Fall, our detector goes crazy. Once I thought it was decaying banana peels in the garbage (boondocking), but am not so sure anymore.

 

Thanks for raising the issue.

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Propane is heavier than air and as such will pool down low, like an invisible light liquid. Is yours placed low and within a foot of the floor? It may be detecting a minute amount of propane leakage. When it goes off if you can smell the Ethyl Mercaptin they use as an odorant, check close to the floor. As well turn on your burners just to check that the Propane you are using does indeed smell like garlic. Some bad batches of Mercaptins (Both Ethyl and Methyl are used) or old batches can lose their odor and are very dangerous because folks cannot smell it.

 

Failing that you can contact Propane suppliers/Fire Dept locally and perhaps rent a gas sniffer? Some Fir Depts. will do a check free of charge as they cost a lot less than responding to CO deaths.

 

If no minute leak exists then I would definitely contact the company and see if they have a recall on them or will replace one that is defective. You should get five year minimum use out of the detector/alarm sensor. One other thing is a sensor can be poisoned from being on the road in traffic emitting normal amounts of exhaust gases. This is why many or most detectors say not for use in RV in fine print on the package. While some folks have gotten by with the home and mobile home detectors, some also find out they got the wrong one when the warranty is voided.

 

Usually a leak that is dangerous from a broken pipe or other major leak will cause the check valve in the valve that connects to your propane tank or cylinder on the end of the pigtail to shut flow down from high flow down to low flow, and none of your RV gas appliances would work.. It will cut off any large loss of pressure when opening the valve on the tank/cylinder to use it.

 

You'll find it, let us know what it turns out to be. I'll put my money on a poisoned sensor first, and less likely bad propane odorant or a tiny leak near the detector/alarm.

Edited by RV

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First of all, you need to determine if it is alarming to CO or to LP. My Safe-T-Alert is 8 years old, Model 70-742. Anyway, when the CO alarm goes off, it does four beeps, then five seconds off then four more beeps and has a steady red light. If LP is detected, the audible signal is constant and the red light flashes.

 

Four nights ago at 3 am, my CO detector started sounding. I thought it was malfunctioning as I had no source of CO in my trailer going at the time. However, I had also installed a battery operated CO detector in the bedroom about a year ago and it was showing 30 ppm also. I thought maybe someone outside was idling a vehicle or running a generator or something similar, but no such thing.

 

I opened a couple of windows and turned on my exhaust fan. Both detectors cleared and went to zero within a few minutes. Everything was fine until that evening, when both detectors went into alarm again.

 

Long story short, I went online and researched what if anything could cause a false reading on CO detectors. Hydrogen off of a battery was one. I had just added water to my house battery the day before. So, I checked the battery. When I opened the battery compartment, I found a strong odor and a very hot battery with less than 9 volts. Evidently, hydrogen off of that battery had made it's way into the trailer and caused the CO detectors to alert. Replaced the battery and no problems for two days now.

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The unit referred to in the original post has two separate sensors, one for LP and one for CO. The LP sensor will react to pretty much anything flammable including methane emitted from animals. The CO sensor is totally different.

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Just an aside, but CO/LP combined units out to be outlawed as the two gasses have very different properties and sensors need to be in different places. LP monitor should be just above the floor. CO monitor should be in the bedroom area at shoulder height.

 

Barb

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Just an aside, but CO/LP combined units out to be outlawed as the two gasses have very different properties and sensors need to be in different places. LP monitor should be just above the floor. CO monitor should be in the bedroom area at shoulder height.

 

Barb

 

I agree they should be different, but not for weight property reasons. Actually, a CO monitor is recommended to be at shoulder height only because it is easier to read at that height. CO is just slightly less dense than air. It could be placed at any height and be effective. I just think it is confusing to the user to have them both in the same unit.

 

I put the CO detector in my bedroom at shoulder height.

Edited by chirakawa

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We all seem to be assuming that it is the propane side that is alarming, but do we really know that for sure? Does your combination alarm indicate which detector is alarming or does the same alarm go for either one? It is important to know what it is that is alarming before we jump to any conclusions. It can be very difficult to pin down what is causing what seems to be a spurious alarm, but one should make sure that it is a false alarm. I had a problem of that sort with the propane alarm in our RV not so long ago and it was happening with the propane all shut off. The alarm is only 4 years old so should be good, but I have ordered a replacement for it and will be replacing it. There are also propane alarms that are battery only operated and there are some from places like Lowe's and Amazon that use 120V-ac power.

 

As a test, I'd turn off the propane and then see if the alarm goes off. It is pretty difficult to actually prove that a detector is working properly. You can test if it goes off by using a butane lighter that isn't lit and pointing the gas jet into the opening of the propane detector. It should alarm. There are hand held combustible gas detectors, but they are a little bit expensive to keep in an RV.

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I agree they should be different, but not for weight property reasons. Actually, a CO monitor is recommended to be at shoulder height only because it is easier to read at that height. CO is just slightly less dense than air. It could be placed at any height and be effective. I just think it is confusing to the user to have them both in the same unit.

 

I put the CO detector in my bedroom at shoulder height.

 

You do know that my degrees are in Chemistry & Chem Engineering and that I'm married to a Ph.D. Biochemist? CO montior needs to be at a level where normal breathing occurs. CO monitor on the floor means you'll be ill or dead before it goes off.

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You do know that my degrees are in Chemistry & Chem Engineering and that I'm married to a Ph.D. Biochemist? CO montior needs to be at a level where normal breathing occurs. CO monitor on the floor means you'll be ill or dead before it goes off.

 

Well, mine went off twice and I'm not dead and it's mounted a foot off the floor. The specific gravity of CO is .9667. It is well dispersed within normal air. I have a lot of practical experience with CO and it's detection and monitoring, but I'm not going to argue with an engineer.

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We all seem to be assuming that it is the propane side that is alarming, but do we really know that for sure? Does your combination alarm indicate which detector is alarming or does the same alarm go for either one? It is important to know what it is that is alarming before we jump to any conclusions.

 

You can test if it goes off by using a butane lighter that isn't lit and pointing the gas jet into the opening of the propane detector.

 

No, we are not all assuming that it is the propane side that is alarming. Read the first sentence in post #5. However, this is the reason I don't like the combo units. When an alarm is sounding is not best time to dig out the owner's manual and try to figure out which sensor is in alert.

 

Using a butane lighter to test a gas detector is a good way to ruin a perfectly good detector.

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Why? My wife tests our smoke alarm all the time cooking. :ph34r: All your doing is letting it detect the gas. Reset it and leave it alone. As someone that has had CO poisoning and survived, I would suggest that the monitors need to be where your head stays, bed height in the bedroom, sitting head height in the living room. I replaced the all in one unit with 3 separate alarms, 1 bedroom CO, 1 livingroom CO, 1 propane at living room floor height

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As someone that has had CO poisoning and survived, I would suggest that the monitors need to be where your head stays, bed height in the bedroom, sitting head height in the living room. I replaced the all in one unit with 3 separate alarms, 1 bedroom CO, 1 livingroom CO, 1 propane at living room floor height

 

I agree with your placement, especially since you probably don't have any children in your RV to mess with them. However, I can tell you that after taking hundreds, probably thousands, of readings with high dollar CO instruments that the difference between readings at eye level and readings at knee level are insignificant.

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The LP monitor will detect LP gas that has not combusted, which will sink to the floor because it is cold and heavy. CO monitor detects the product of combustion (carbon monoxide) which is lighter than air and will rise because it is a smaller molecule that either N2 or O2 and because it is hot. Just like a hot air balloon rises through cold air. Small differences, but CO detector really should be in the normal breathing area.

 

LP monitor detects any flammable gas whether it is propane, butane, ethane, or methane. Set a paper bag on the floor with apples in it, close it up and open in a couple of days - alarm will probably go off because of the ethene the apples give off. Ethene is used to ripen green fruit as it moves across the country. Dog with upset digestive tract can set it off, as can being down wind of a feed lot!

 

Barb

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Using a butane lighter to test a gas detector is a good way to ruin a perfectly good detector.

It don't harm anything and I have done so for years, after learning to do so from the manual that came with one of our detectors. Propane and butane are both products of petroleum distillation and either will be detected by the alarm. The alarm actually detects hydrocarbons which both contain, along with several other gasses. From propane dealer association.....

 

An easy test for a propane / LP detector is to activate, but not light, a portable propane/butane lighter next to the propane / LP detector. If the propane / LP detector is working, the detector should quickly activate with an alarm.

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It don't harm anything and I have done so for years, after learning to do so from the manual that came with one of our detectors. Propane and butane are both products of petroleum distillation and either will be detected by the alarm. The alarm actually detects hydrocarbons which both contain, along with several other gasses. From propane dealer association.....

 

I've seen videos of people seating truck tires on the rim using flammable gases also, but I don't recommend the procedure. It is very easy to fry the sensor in a gas detector by introducing a flammable in that manner. Just because you've done it and haven't ruined it doesn't make it a good practice.

 

Here is a link to the manual for the Safe-T-Alert combo LP/CO detector. On page 3 in the right hand column is the Test Procedure with a clear warning about doing what you suggest. But, you feel free to do as you please. As someone who has ruined more than one sensor by introducing it into a too rich environment, I will decline to do so with my own equipment. https://www.safehomeproducts.com/shp2/data/manuals/70-742.pdf

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It was the CO red light that was lit. Please remember that windows were open, plenty of air.

It is factory mounted at floor level.

 

I took the pillow off the detector this morning when the ambient temperature reached 60 degrees in the camper.

Made coffee and read emails. No alarm occurred. The detector has been on all day and not false'd even once.

 

My guess is that it will probably go into alarm sometime tonight when the ambient temperature drops (below 60 degrees, hopefully).

If it goes off, it will strengthen the correlation between alarm and temperature.

 

I have a hypothesis that this is a temperature related problem. The detector was installed with ambient temperature at 88 degrees - upon installation it takes ten minutes for the detector to initialize itself and perhaps now has a mean operating temperature range based on what it "saw" when it was installed.

 

However, I doubt that. The previous detector began alarming at about the same time that the pollen count went up.

Observe, hypothesis, test.

 

And I will be buying and installing a stand-alone CO detector as a back up.

 

 

 

 

 

 

 

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Chirakawa

 

You didn't see this in the manual?

 

 

This detector is UL® listed as a CO Propane and Methane (Natural Gas)
detector for RV use. Other explosive gases detected, but not tested by UL®,
include Acetone, Alcohol, Butane, and Gasoline all of which you may have
in your RV.

 

It will detect any of those - which is why hair spray will often set up an LP alarm. Also there will be some butane in any propane that you get.

 

The use of the test button is a way to avoid saturating the sensors - but all that really tells you is that the test circuit is working, not whether the sensor actually picks up the vapor or not. While I wouldn't use the butane all of the time, once in a while it is not a bad idea. 25 yrs of doing EH&S work, I always calibrated my test equipment with small known samples of the particular material of concern.

 

------

 

 

Rich, sure sounds like either it is temperature or pollen related. If pollen related that is a terrible design - - but then I think the whole combo idea is terrible. If it were me, I'd take it back and let them know it isn't working and just replace that with a propane alarm and then add your CO alarm in the bedroom area.

 

Barb

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The use of the test button is a way to avoid saturating the sensors - but all that really tells you is that the test circuit is working, not whether the sensor actually picks up the vapor or not. While I wouldn't use the butane all of the time, once in a while it is not a bad idea. 25 yrs of doing EH&S work, I always calibrated my test equipment with small known samples of the particular material of concern.

In addition, you don't shoot pure butane into the opening with the lighter as it will mix with air and I have found it does just fine held a couple of inches from that opening. It really doesn't require a very high concentration of the butane or other hydrocarbon to trigger the alarm. I'm sure that you could damage the sensor is you held the lighter there long enough or had a large enough supply, but most lighters just don't put out that much gas.

 

Rich, like Barb I think that you probably are getting an alarm caused by something other than propane, but it may be tough figuring out what. The problem that we have had with ours don't seem to have much pattern, other than always being at night. I have suspected that at least part of our problem is one of "out gassing" from construction materials. I am about to get back to work on ours for coming seasonal travel. The RV has been stored and I disconnected the alarm when it went off one night with nobody in the RV and the propane had been shut off for a month. My first attempt will be a new detector but mine is separate from the CO side. I don't like the combo units just because they are too hard to pin down, but it does help that yours has a light to say which side is alarming. I've seen some that didn't have that light.

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Chirakawa

 

You didn't see this in the manual?

 

 

It will detect any of those - which is why hair spray will often set up an LP alarm. Also there will be some butane in any propane that you get.

 

The use of the test button is a way to avoid saturating the sensors - but all that really tells you is that the test circuit is working, not whether the sensor actually picks up the vapor or not. While I wouldn't use the butane all of the time, once in a while it is not a bad idea. 25 yrs of doing EH&S work, I always calibrated my test equipment with small known samples of the particular material of concern.

 

Barb

 

I think I stated earlier that the LP detector will trigger on other flammable substances. It is listed as a propane detector because that is what it is calibrated to.

 

Your last sentence sums it up. You calibrated your instruments to "known samples". These "known samples" are at a predetermined level in a closed source. A cigarette lighter held in open air at a variety of distances away from the sensor is not a "known sample", thus the warning in the manual about not doing it.

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It was the CO red light that was lit. Please remember that windows were open, plenty of air.

It is factory mounted at floor level.

 

I took the pillow off the detector this morning when the ambient temperature reached 60 degrees in the camper.

Made coffee and read emails. No alarm occurred. The detector has been on all day and not false'd even once.

 

My guess is that it will probably go into alarm sometime tonight when the ambient temperature drops (below 60 degrees, hopefully).

If it goes off, it will strengthen the correlation between alarm and temperature.

 

I have a hypothesis that this is a temperature related problem. The detector was installed with ambient temperature at 88 degrees - upon installation it takes ten minutes for the detector to initialize itself and perhaps now has a mean operating temperature range based on what it "saw" when it was installed.

 

However, I doubt that. The previous detector began alarming at about the same time that the pollen count went up.

Observe, hypothesis, test.

 

And I will be buying and installing a stand-alone CO detector as a back up.

 

 

 

 

 

 

 

 

I've never heard of a CO monitor alerting to pollen or temperature fluctuations, but you may be on to something. If the CO sensor is going through it's warm-up period properly, it shouldn't be temperature sensitive. With the windows open, it sure doesn't appear that any inside CO source is the culprit.

 

One other thing to be aware of is any activities in the immediate area around your RV. Many CO events where people died or were seriously ill, the source of the CO was outside the structure. The most obvious incident would be after weather events when people lost electricity and were using generators on their patio or in their garage. I saw four people go to the hospital after a stump grinder operated for 30 minutes about 20' from a house. The exhaust just happened to be directed toward the house and filled the house with CO. Cars running, tractors working, forklifts operating nearby are other examples.

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Another night has passed and ambient temperature dipped to only 61 degrees and NO alarm.

Thinking about smoke detectors. . .my experience is that when a smoke detector battery goes low, it will start to chirp at night.

Maybe because the temperature drops at night?

 

I haven't checked the camper battery voltage. Camper is new to us. Only had it three months. It's a 2014 model.

Battery idiot light shows full. Camper jacks can lift and lower on battery power alone.

I'm pretty sure battery voltage is good but will check with a multimeter later today.

 

We have a few days of warm temperatures ahead and may not be able to test the temperature drop idea until the next cooling trend.

 

The immediate area has no CO source. For interest, it can been seen here: Google satellite shot (Our house is vacant, used just for showers, laundry and some cooking. Adjoining house with all the cars is vacant and in foreclosure. Nursery shuts down at 5pm and is vacant. Nearest neighbor is quiet.)

No stump grinders, generators or that short of thing capable of making CO..

 

Unfortunately, I was too quick to throw the old CO/LP detector away and should have kept it for testing purposes.

Hopefully, I'll have a few nights of uninterrupted sleep.

I will report any results or changes as they occur.

 

Thank you for discussion input - it has spurred new thoughts and ideas.

 

 

 

 

 

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I haven't checked the camper battery voltage. Camper is new to us. Only had it three months. It's a 2014 model.

Battery idiot light shows full. Camper jacks can lift and lower on battery power alone.

I'm pretty sure battery voltage is good but will check with a multimeter later today.

 

 

 

 

 

 

 

 

 

 

According to the manual, the detector will operate normally down to 7 volts DC. I'm pretty sure you are above that, judging by your comments.

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