Beeping CO Sensor Strangeness

[Shano]

So my CO sensor is acting strangely - it was beeping and then my dockmate heard it and opened the door and that stopped it. This is the second time the beeping stopped when the door was opened and fresh air came in. The curious thing is that there is no combustion going on, the propane tanks are shut off, the diesel heater is off, and of course the engine is not running. I went down and checked on it last time it was beeping and read the manual and did the test by pressing and releasing the test button and the monitor went through the cycle twice as per the manual. Faulty sensor or any other ideas?The boat is 2017 so shouldn’t be at the end of life of the sensor. I did notice that the green light was off the other day so I checked the fuses and when I re- inserted the fuse the green light came back on so a loose fuse connection posssibly? Any other ideas?

 

[Favunclerich]

Open the sensor and check the manufacturing date. Could it be that your 2017 boat was built in 2016 with a sensor that was built in 2015 and is now five years old and has reached its end of life?

 

[knotflying]

I will assume your batteries are charged okay? When there is a low charge in your batteries very often the co detector will beep intermittently.

 

[Shano]

Thanks Guys, the boat is connected to shore power and the batteries are fully charged. I will check the date on the inside of the cover and check that out and report back.

 

[Shano]

The CO sensor date is Sept 2021 but because the sensor is acting strangely I will replace it a year earlier than the expected EOL date.

 

[Thatguy]

I would start with replacing the CO detector, but bear in mind that it is possible for Hydrogen Gas to trip a consumer level CO detector. Hydrogen gas can be generated during charging of the batteries. Hydrogen will rise - is it possible for a battery compartment to vent into the cabin? I don’t know.
JP

 

[Shano]

I would start with replacing the CO detector, but bear in mind that it is possible for Hydrogen Gas to trip a consumer level CO detector. Hydrogen gas can be generated during charging of the batteries. Hydrogen will rise - is it possible for a battery compartment to vent into the cabin? I don’t know.
JP

That is interesting. I discussed this idea of a battery gassing causing the sensor to go off with my dock mate and we thought that because it is hydrogen gas that it would be unlikely. The engine and thruster batteries are very close physically but like you not sure how likely it is that enough gas could get into the cave area where the sensor resides. Maybe either my thruster or engine battery is faulty and thus is gassing more? It hasn’t happened since but I’m not at the boat 24/7 so really not sure. I’ll keep a keen nose on it and see. Thanks for the insight. I’ll replace it soon but chinook just opened at Sandheads so I’m going to be busy for a while!

 

[doke01]

Look around at your neighbors as well. I've had neighboring boats set off our alarm before due to CO build-up. It could be their exhaust exits towards your boat, for example, and gets sucked into yours with the right wind direction. Even closed up these boats are not air-tight and there is airflow.

 

[BB marine]

Hydrogen Gas can set a CO detector into alarm. If the battery charger is not operating correctly (auto charging) or a battery has a bad cell the bad battery will cause the battery to continuously charge. If any batteries are paralleled to this battery it can cause them to over charge and gas off. Do to the ACR installed the batteries would all be paralleled and the charge rate to the good batteries could cause them to gas off. The Cutwater or Ranger build does not have sealed bulkheads between the engine compartment and living space. Sealed bulk heads is a marine industry standard with boats with living quarters but not required with diesel powered water craft. The Cutwater or Ranger does not have a engine compartment ventilation system installed. It has spaces between the cockpit sole liner and and the hull some blocked by wire looms and hoses allows air in and out of the cockpit. Tailgating while operating the boat can cause vapors to linger in the cockpit and infiltrate living quarters. ( some have experienced soot stains in the living quarters) Outside ventilation intake and exhaust is an marine industry standard with inboard powered vessels. It is not required with diesel powered boats but recommended. The simple passive vents located on the exterior of the hull if installed allows for air flow into the compartment and out of the compartment. Without a true ventilation system situations of gassing batteries, propane leaks, tailgating while cruising, higher than advisable compartment temperatures may propose less than desirable condition. In the case of the CO sensor possibly alarming because of CO or Hydrogen in the living space is evidence of the issues that can happen without sealed bulkheads and a good machinery or engine compartment ventilation system. This is the reason that most marine manufactures install them even if it is not a requirement. Never over look a CO sensor if it is alarming find out why. Cudo's to Shano for starting the thread and asking questions.

 

[Shano]

Just to follow up, I purchased a new Xintex CO monitor and installed it. The old one’s EOL date was Sept 2021 but it was acting erratically so I had to replace it. So far it tests as it should and I expect that it will not beep when it shouldn’t. The new monitor looks different but the mount lines up with the old mount’s holes and it was an easy install.

 

[pleeson]

I'm pretty sure your sensor timed out. I've gone thru two on my 2013 already and that's with indoor dry storage and I would say pretty dust free conditions. If your new unit fixes the problem you've nailed it.

 

[S. Todd]

I too had a CO Sensor fail in a similar manner a year before the expiration date. Replaced it with a new one and all was good. Unfortunately, the manufacturer changed the style so it was not a simple plug and play install.