No reason unless your hard wired CO detectors are wired to a "kill circuit" on your generator.

I've got 3 of the battery powered CO/Smoke combo units onboard. This is in addition to the three hard wired rigs, one of which is not functional and I've not replaced

 

I actually have both. I replace the marine ones since they are there and have any extra one from the store in the aft berth where the kids sleep

 

Yes I can. They are not marine rated and built to survive long term in a high moisture environment that moves. Is it really a savings if we lose loved ones and only have non marine CO detectors? I choose to save money elsewhere.

That said I run both kinds at the sleeping berths in my boat…

 

Define "crazy expensive." You can get them for less than $200. In boat bucks, that's like $2.00. 12 volt hardwired with battery backup is the way to go. The home versions are 110 AC powered -- not great for a boat. Probably not an area I would cheap out on.

 

I have both. I replaced my CMD4’s with CMD5’s when the 4’s timed out.

 

Too late... Probably looking at CMD6s now.

-Kevin

 

There is a difference. The marine rated have several different trigger profiles based on CO concentration and time exposure, the home ones do not. Basically reduces the chance of false alarms.

For the record, I replaced the original hardwired CMD2 with new CMD5 last year, and I have a couple Kidde onboard.

 

You

This^^^^
You will find that the home versions are too sensitive and will false alarm a lot. Technically its not a false alarm I guess. They will be detecting CO. I have one in my cabin (despite not having a genset) for when I am at anchor rafted up with others that run their generators. Also, when I am running, if the canvas is not removed in front, it does alarm when operating at idle speed from station wagon effect. I think the marine ones have a bit more selective sensitivity.

 

Looks like the CMD6 is $99 at Defender. But like everything cool these days....backordered

 

Somewhat related, I was looking at smoke detectors online last night. Any recommendations on brand/model, and then where to install in the cabin?

 

We keep the OEMs up to date plus 4 from Home Depot.We have 5 fire extinguishers, Life jackets in both sleeping quarters, and a glass breaker in the aft state room to get out the side window if needed. With some of the fires at marinas the last few years where people died in the fire we took a hard look at what we would do in similar situations. The 55 has no way out of the aft stateroom other than up the steps to the helm and out the stern.

 

With some of the fires at marinas the last few years where people died in the fire we took a hard look at what we would do in similar situations.

Same

Great comment, while laying in the forward bed this weekend I though to myself I could get out of the hatch if I had to, but the aft room, not so much. The sliding cabin entry door is broken as well, jamming up. I am making that a priority to fix now.

 

I don't know...I've had three of the "home" units linked below for several years now. When I'm parked facing the wrong direction and some ding dong lights up his engines and idles for long enough...they all go off at the same time, including the hard-wired units.

If anything I think my marine (one CDM5 and some random old one) units tend to go off before the battery units. But that's just my experience...

https://www.amazon.com/gp/product/B000MXJ498/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

I asked the question because my 3 Fireboy CO detectors are the original ones and kept falsely going off, so I unplugged them. I couldn't determine how to pull them off the wall, so I bought the Home Center brands (First Alarm). And I say crazy expensive as they are double the price of the units for home use (and the home ones have digital displays). And I trust the home units for my home completely, so why wouldn't I trust them for my boat? If I didn't trust them for home, I wouldn't think twice about the price difference. And there are many products that both car/home share with boats and many times the marine products, even though the same, are priced high because they are for a boat. Thus the reason I started this thread. Someone commented that the boat CO detectors are more moisture resistant. The Fireboy website indicated this as well.

It sounds like many have both. I guess my plan will be to replace the original Fireboy CO detectors with new ones and keep my 2 First Alarm ones as well. I have 3 in the cabin and want to add one to the cockpit. Especially since I'm getting a new camper top and living in Michigan where the weather sucks early and late in the year, I run with my camper top on a lot and worry about CO in the cockpit. My old canvas is so bad there's a ton of air circulation. My new canvas will be tight.

 

Q: Do the marine rated CO detectors also function as smoke detectors?

 

If it is a dual unit otherwise no, you need two different units. I have separate smoke and CO on our boat.