# Propane real vs. best practices



## bajaking (Jun 6, 2013)

I'm just about done replacing the entire dual-tank propane system on my new-to-me old boat, from tanks to stove/oven and heater and everything between. First boat I've owned with propane.

So we all know the best practice is to turn everything off, including the valves at the tank, when not being used. Every book, manual, blog, and forum rat says so. Not a big deal, it's only a couple steps into the cockpit to open and close the valves. 

But is that what everyone really does, always? 

I have to admit it seems tempting, especially in cool weather after a long day that includes propane use right up to bedtime -- a pre-bed cuppa while warming up next to the propane heater in one's PJs and sleeping cap -- to just close the solenoid and head to bed, then open it again for breakfast in the morning, saving two trips to the tanks. I would off course close the tank valves before leaving the boat unattended for more than a few minutes.

Is that practice pure sin? 
Surely more than one drunken sailor has slept off their grog more than once while forgetting to close their tank valves, maybe even forgetting to close the solenoid altogether, and lived to heat up a hangover cure the next morning. No?

Sincerely,
Fastidious and fearful of fiery death

p.s. feel free to pm if you're sure your insurer will read your response and void your policy!


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## capta (Jun 27, 2011)

If you have the solenoid valve properly placed at the tanks (properly installed outside or in a vented locker), I see no reason to turn off the valve on the tank when you are aboard, or just leaving to go out for a few hours, unless you suspect a problem with the system.
If I were leaving the boat for an extended period, then yes, I'd shut off the tank.
If you consider the number of propane equipped boats out there and the number of explosions from the gas, even though many using it do not take any precautions, I'd guess you'd have a better chance of being hit by a meteorite than being killed by a propane explosion.


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## chef2sail (Nov 27, 2007)

We shut ours off at the tank after using...it’s really no big deal to do that. Yes we also shut off the solenoid.


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## MarkofSeaLife (Nov 7, 2010)

I turn mine off when I go on vacation away from my boat.


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## SanderO (Jul 12, 2007)

Only shut the tank valve when leaving for long periods...leaks (there are none) will drain outboard.


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## capta (Jun 27, 2011)

MarkofSeaLife said:


> I turn mine off when I go on vacation away from my boat.


"go on vacation"????
Aren't you *always* on vacation? lol


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## MarkofSeaLife (Nov 7, 2010)

capta said:


> "go on vacation"????
> Aren't you *always* on vacation? lol


Ummmm, yes. When I am on holiday from my vacation :grin


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## RegisteredUser (Aug 16, 2010)

My routine...
When cooking is done..edge of being done..i turn off the tank then solenoid then burner then take pot or pan off burner.
If it is pouring..skip tank..unless sufficiently buzzed that the rain is a short buzz thrill


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## capecodda (Oct 6, 2009)

++ for the manual valve is only when I leave the boat for a few days.

The solenoid is for every day use while living aboard or cruising. 

One other paranoid idea is when you are done cooking, every once in a while with a burner lit, shut it off with the solenoid instead of the controls on the stove (shut the stove off after the flame extinguishes). It will take you longer to light it next time to get gas in the line, but you'll verify the solenoid works. This is not an every day thing either, but a good test that the system is working.

Y(Paranoia)MV YPMV...and I never want to discourage anyone for being more safe...so whatever floats your boat. Cool you updated everything!


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## fallard (Nov 30, 2009)

Propane leak anxiety? Not on my boat! Our cooking gas is lighter than air—unlike propane, which can settle in the bilge.

We have CNG and once we got a second tank, the inconvenience of limited CNG exchange stations faded. Hopefully, the resurgence of CNG fuel in the non-boating world will turn the situation around to make CNG refills more convenient. 

Meanwhile, I don’t turn off the gas while I am cruising. The only downside in not shutting off every evening over the years, is that we had a regulator failure a number of years ago that vented the gas outboard (the good news), but depleted the tank in about 3 days.


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## Don L (Aug 8, 2008)

I never go out to cockpit, get into the propane locker, and shut the valve on the tank,, except for when i need to replace the tank.

Ever stop to think how many 100s of millions of homes have gas stores that have nothing to isolate the gas source from leaking?


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## RegisteredUser (Aug 16, 2010)

So it does happen

Cng used to be the choice. Makes sense


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## boatpoker (Jul 21, 2008)

Full time liveaboard since 94'

The solenoid is used after each propane use.
The only time I've turned off at the tanks is if I'll be away from the boat for a few days.

I do make sure that my regulator, solenoid, fuel lines and pressure guage don't get older than about 7yrs.

These have all been fitted so that replacement of everything is a 1hr. job.


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## SanderO (Jul 12, 2007)

boatpoker said:


> Full time liveaboard since 94'
> 
> The solenoid is used after each propane use.
> The only time I've turned off at the tanks is if I'll be away from the boat for a few days.
> ...


Exactly what I have been doing for decades now.


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## Minnewaska (Feb 21, 2010)

Each time, when I'm done cooking, I leave the burner lit and switch off the solenoid breaker. If the flame goes out, the solenoid is closed. Then I turn off the burner knob. The hoses are therefore, no longer pressurized either. I see no overwhelming reason to close the tank, each and every time, if it's properly installed in a vented locker and I know it's closed off from the rest of the boat. 

I don't object to belt and suspenders, but I'm okay with just a belt. I know there could be edge cases where the solenoid is only close enough to extinguish the flame, but may let a little gas past. Although, I've never heard of that edge case happening. Then you'd need to forget and have the burner knob open too. Perhaps someone accidentally turns the breaker back on, however, I changed mine to be Red, so it was more obvious what it was.


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## MarkofSeaLife (Nov 7, 2010)

Minnewaska said:


> Each time, when I'm done cooking, I leave the burner lit and switch off the solenoid breaker. If the flame goes out, the solenoid is closed. Then I turn off the burner knob. The hoses are therefore, no longer pressurized either. I see no overwhelming reason to close the tank, each and every time, if it's properly installed in a vented locker and I know it's closed off from the rest of the boat.


Speaking seriously pour une moment...

Letting all the gas out of the hose, or even turning off the bottle, can lead to an air bubble in the hose. So if the gas is turned on again, lit at the stove, then the person turns away the gas may go out when the air bubble arrives at the stove. If the heat sensor (thermocoupler?) is faulty, and who knows is it is?, then you are letting gas into the boat.
Or thats the easiest way I can see to get an explosive amount of gas into the boat. Then the person sees the gas is out and tries to light it up again. BANG.

My method of keeping the gas safe is using a hand-held gas detector and running it weekly over all the connections.

BTW the other difficult bit in the gas system is the hose from the stove to the bulkhead. Its flexible but the gimbalised stove moves the whole time so t hat flexible hose gets brittle with age. after 20 years your continuous tugging on the hose there could be a problem.

In general I think gas stoves are extremely safe. The last person killed in a cruising situation, IIRC, was about 5 years ago in the Caribbean who blew up accidentally.

Again, the real risks on the boat are falling off, dinghys, booze, and heart attacks...

Mark


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## SanderO (Jul 12, 2007)

I should note that I have a shut off inside the galley which cuts off gas from the stove. I use that also at times when leaving the boat unattended for long periods.


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## bigdogandy (Jun 21, 2008)

While we’re talking cooking safety should note that enjoying safe snacks means always using a condiment.


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## Minnewaska (Feb 21, 2010)

MarkofSeaLife said:


> Speaking seriously pour une moment...
> 
> Letting all the gas out of the hose, or even turning off the bottle, can lead to an air bubble in the hose. So if the gas is turned on again, lit at the stove, then the person turns away the gas may go out when the air bubble arrives at the stove. If the heat sensor (thermocoupler?) is faulty, and who knows is it is?, then you are letting gas into the boat.


I see your theoretical point, but it still requires multiple failures: air bubble enters, person turns away after lighting and the thermocouple is faulty. Odds seem pretty low for a triple failure, don't they.

I'm not really sure I see how this air bubble gets in. It would have to back feed from the stove itself, as there is no other entry point. Air is lighter than propane, so the lines would have to go up, I would think. I've never had this happen.


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## krisscross (Feb 22, 2013)

I always turn off the gas bottle, solenoid, and of course the stove knob. On my boat it’s very easy to do and just takes few seconds. Occasionally I regret turning off the bottle when it’s cold and raining outside.


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## boatpoker (Jul 21, 2008)

Minnewaska said:


> Each time, when I'm done cooking, I leave the burner lit and switch off the solenoid breaker. If the flame goes out, the solenoid is closed. Then I turn off the burner knob. The hoses are therefore, no longer pressurized either. I see no overwhelming reason to close the tank, each and every time, if it's properly installed in a vented locker and I know it's closed off from the rest of the boat.
> 
> I don't object to belt and suspenders, but I'm okay with just a belt. I know there could be edge cases where the solenoid is only close enough to extinguish the flame, but may let a little gas past. Although, I've never heard of that edge case happening. Then you'd need to forget and have the burner knob open too. Perhaps someone accidentally turns the breaker back on, however, I changed mine to be Red, so it was more obvious what it was.


Thermocouple would try to close solenoid again and if that failed, you still have your LPG fume detector.

PS. I've never seen a partial (edge) solenoid failure either. when they do fail, they fail closed.


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## bajaking (Jun 6, 2013)

Wow, lots of responses, thanks! I'll probably ease into things by starting with belt and suspenders - closing tank valves every morning before leaving for work and opening up again (and checking gauges for leaks) when I get home to the boat - but reduce to just belt (tanks always on, solenoid calling the shots) after I'm confident everything is good. I also have one of those handheld gas detectors in addition to the panel-attached sniffers. Fun to use and worked well when testing my little butane camp stove; next I'm gonna test for methane in the w.c...



boatpoker said:


> Thermocouple would try to close solenoid again and if that failed, you still have your LPG fume detector.
> 
> PS. I've never seen a partial (edge) solenoid failure either. when they do fail, they fail closed.


Maybe I missed something: does my stove (new Force 10) communicate with the propane locker solenoid somehow? Or is there a solenoid inside the stove controlled by the burners' thermocouples?


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## SanderO (Jul 12, 2007)

Solenoid is an electric powered valve which is used at the gas bottle location... It is normally CLOSED. When you energize the solenoid it opens and allows gas to flow into the hose/line to the cooking device.

If you close the solenoid the pressure will drop if there is a flame burning. I doubt the line will be purged however.

You should have a gas sensor w/ alarms below the stove. Propane is heavier than air and will sink into the bilge.


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## bajaking (Jun 6, 2013)

Thanks Sander, I get that much, so I was confused by boatpoker's suggestion that the "thermocouple would try to close the solenoid". I'm pretty sure the only thing controlling my solenoid is the Xintex panel and its on/off switch and sniffers, not the stove itself. I'll have to pull the Boatowner's Mech & Elec off the shelf; realizing now that I have no idea how the stove itself works, just that there's a valve inside it somewhere that gets closed if the thermocouple isn't heated by the fire of a properly operating burner. But without electrical power to the stove, this is presumably not a solenoid type valve, right?


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## MikeOReilly (Apr 12, 2010)

I do shut off the valve at the tank most of the time after use. I'm not religious about it, and sometimes forget (or am too lazy to go up in the cold), but most of the time our practice is:

1. Turn off solenoid.
2. Let burner go out.
3. Turn off stove valve.
4. Then close the valve on the tank.

Our tank is relatively easy to access, so it's kinda in the _'why not do it' _category. If it was harder to get to I'd likely not bother. But it does feel like good practice.


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## boatpoker (Jul 21, 2008)

bajaking said:


> Thanks Sander, I get that much, so I was confused by boatpoker's suggestion that the "thermocouple would try to close the solenoid".


The thermocouples shut off the propane at the stove.


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## Minnewaska (Feb 21, 2010)

SanderO said:


> .....If you close the solenoid the pressure will drop if there is a flame burning. I doubt the line will be purged however.....


I'm sure that's right. However, if you shut the solenoid, with the flame burning, it must take the pressure off, even though there would still be propane in the line. It should reduce the risk of pressure forcing a leak through a loose fitting or small breach.

I don't want to underplay the risk of propane leaks. However, note how hard it can be at times to light a backyard bbq. That's because propane only burns in a narrow gas/air mix range. A small leak needs to accumulate sufficiently for that mix to occur. I'm not willing to place bets on when that is, so zero leaks are the goal. The point is only whether it's leaking long enough. Low odds from an unpressurized hose. I think.  YMMV


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## SanderO (Jul 12, 2007)

This is kind of a weird discussion.

Strove uses thermocouples.... no flame it shuts down the gas at the hob.

Thermocouples are widely used in science and industry. Applications include temperature measurement for kilns, gas turbine exhaust, diesel engines, and other industrial processes. Thermocouples are also used in homes, offices and businesses as the temperature sensors in thermostats, and also as flame sensors in safety devices for gas-powered appliances.

Gas remained in the plumbing.

Shut down using a solenoid at the tank and or the tank leaves gas in the plumbing up to the thermocouple. 

No way to purge propane from the plumbing by closing valves.

When you run out of gas.. you have nothing to ignite.

When you change the tank it takes some time for the pressurized gas to purge/replace the air with propane.


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## Don L (Aug 8, 2008)

Wonder how many of the gas paranoid people also shut all thur valves when not it use. Are they the same ones who when living on land shut off the gas and electric each time they leave?


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## MikeOReilly (Apr 12, 2010)

Yes, I forgot to add the thermocoupler in my steps.

1. Turn off solenoid.
2. Let burner go out.
_2a. Thermocoupler automatically closes the burner valve once the heat dissipates. _
3. Turn off stove valve.
4. Then close the valve on the tank.

Like I said, I'm not particularly paranoid about this, but since my tank is easy to access (it sits on my cabin top, under a soft cover), it just seems like a simple thing to do. We have a simple visual sign to know when it is closed or open.

Sometimes I forget. And sometimes I'll go days without closing it (often if the weather outside is frightful ). But it just seems like good practice to close it when not in use. It feeds my little _black box._

To be honest, I've not really thought much about the whole line pressurization question. I let the flame burn out as a check to know the solenoid is working (it always has). Obviously the line is slightly depressurized, but it certainly still contains gas. I'm not worried about this.


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## bigdogandy (Jun 21, 2008)

Hmmmm.......I’m not on the boat currently, but don’t recall a thermocouple on the burners.....Mariner Princess with piezo ignition. On the oven, yes - if the pilot light goes out the thermo there is supposed to shut off the gas, but I never rely on that. I always light the pilot each time i use the oven....


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## bajaking (Jun 6, 2013)

bigdog, as I understand things, if it's an older stove it might not have thermocouples. Pretty sure the surveyor said the 40 yr old Hillerange that was on my boat did not have them, but I don't trust my memory these days.

https://www.suremarineservice.com/site/PDFs/manuals/Stove-Repair.pdf

Looks like there is no thermocouple on some older units, at least. Seems there was, and presumably still is on current stoves, a "mercury control valve" that is the built-in brother of the upstream system solenoid (presumably this is what boatpoker is referring to).

I'll add that one reason I ditched the Hillerange is that we (surveyor and I) had trouble getting the oven lit. Got the pilot going after many tries, but that was it. The "oven guy" at Sure Marine said the gas tubes in the oven are probably steel, and after 40 years in a boat, corroded and starting to get pinholes, which will only lead to problems.


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## bigdogandy (Jun 21, 2008)

Well, my stove would definitely qualify as “older” - it’s from 1981 and original to the boat 

Still works great, though - the previous owners kept it clean and I have tried to do the same. The oven works great, although it doesn’t get quite hot enough to really do cornbread the way I like it, but the gas control and pilot light / thermocouple components all are still great shape. Dickinson did it right when they put that one together!


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## outbound (Dec 3, 2012)

Also shut off solenoid first then hob. Understand others thinking but would add solenoid being on is a constant draw on your batteries. The habit of doing the solenoid first is a good way to ensure you remember to shut it off.
Think shutting it off doesn’t really completely purge the line. Have never noticed the stove/oven being hard to restart.
When away from the boat turn tank valve off but also unscrew line. Probably ridiculous but also do that on barbecue at home before we leave for the boat.


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## SanderO (Jul 12, 2007)

outbound said:


> Also shut off solenoid first then hob. Understand others thinking but would add solenoid being on is a constant draw on your batteries. The habit of doing the solenoid first is a good way to ensure you remember to shut it off.
> Think shutting it off doesn't really completely purge the line. Have never noticed the stove/oven being hard to restart.
> When away from the boat turn tank valve off but also unscrew line. Probably ridiculous but also do that on barbecue at home before we leave for the boat.


I believe that a gas solenoid on a boat draws no current in the normally closed position. When you ACTIVATE it it open the valve so.... you DO draw current when you use the gas for cooking.

I suppose it depends on how much gas might remain in a shut off gas line... and if there was a leak... what happens to the gas?

A gas sensor is a good idea.

Your gas locker should drain over board.

The balance of the gas plumbing will have leaks settle down as the gas is heavier than air.

If you have active ventilation... such as an bilge exhaust this may remove any propane. Our engine room has an exhaust fan. The engine bilge communicates with other bilges so essentially, but not efficiently air from all bilges is exhaust by this fan.


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## outbound (Dec 3, 2012)

Yup that’s what I’m saying. No draw when off. If you forget to turn it off over time can drain down the house bank. Don’t see that red light may have depleted the bank to a significant degree. Think it’s about an amp.


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## SanderO (Jul 12, 2007)

outbound said:


> Yup that's what I'm saying. No draw when off. If you forget to turn it off over time can drain down the house bank. Don't see that red light may have depleted the bank to a significant degree. Think it's about an amp.


There are some very small always on loads... and of course can over time drain a battery bank.

Our bank is almost 500 AH and we have over a 100 watts of solar. The nest is that there is no drain on the batts for these small loads. All distribution switches are left in the open position when the devices are not in use. So for the way we use the boat we usually have topped up batts.

Things like the LED interior lights, radios and the computer are draining the batts. Our refer is engine drive so we typically run the diesel each day with a high output alt we replace use amps.

Topped off batts last longer than cycled ones I am told.


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## Minnewaska (Feb 21, 2010)

Not sure if some missed this point. Watching the flame go out, means the pressure has dropped in the line, not that the line is purged. This unpressurized state is not going to escape through any breach that isn’t a true break open to atmosphere. If you hose breaks in two, the propane inside will leak, even if the tank valve is closed. Removing pressure takes away the possibility that a fitting is starting to allow a pressure leak.


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## SanderO (Jul 12, 2007)

outbound said:


> Yup that's what I'm saying. No draw when off. If you forget to turn it off over time can drain down the house bank. Don't see that red light may have depleted the bank to a significant degree. Think it's about an amp.


There are some very small always on loads... and of course can over time drain a battery bank.

Our bank is almost 500 AH and we have over a 100 watts of solar. The nest is that there is no drain on the batts for these small loads. All distribution switches are left in the open position when the devices are not in use. So for the way we use the boat we usually have topped up batts.

Things like the LED interior lights, radios and the computer are draining the batts. Our refer is engine drive so we typically run the diesel each day with a high output alt we replace use amps.

Topped off batts last longer than cycled ones I am told.


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## MikeOReilly (Apr 12, 2010)

My solenoid draws about 1 amp when on. It's easy to see on the meter.


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## outbound (Dec 3, 2012)

We had 1024 in the house bank when the lifelines were installed 4 years ago. Recent load test shows just under 1000 as we baby them. They rarely if ever go below 70%. They go to 100% at least 2 to 3 times a week. So leaving the solenoid on isn’t much of a concern. Still spent years and years with small pb acid banks when it was a concern. Think our world changed with having panels and the D400s but not everyone has such a set up. Then that one amp is a concern. Remember having no regular access to shore power and no alt energy with a small bank. Think there’s still a lot of boats like that. 
With agms, especially on a cruising boat, getting those last few amps to get to 100% takes time. See the arrow on the Philippe go in/out of the bank. Commonly even turn off the invertor when on float to get rid of all the little draws as I want to be at 100% as often as I can. Think Li and fireflies are a big plus in this regard. But haven’t gone that route yet.


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## Minnewaska (Feb 21, 2010)

I’ll add that shutting off the solenoid, after each use, to watch the flame expire, demonstrates it will still work in an emergency. Good to know.


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## SanderO (Jul 12, 2007)

Minnewaska said:


> I'll add that shutting off the solenoid, after each use, to watch the flame expire, demonstrates it will still work in an emergency. Good to know.


it's normally off... is the emergency you refer to... opening the valve?


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## Minnewaska (Feb 21, 2010)

SanderO said:


> it's normally off... is the emergency you refer to... opening the valve?


Yes, they fail closed. If one leaves it open (on) permanently, they don't know it isn't stuck or there isn't a short that sends power, keeping it open, despite tripping the switch down below. Failsafe closed is more a comfort to know it won't reopen itself. I like to visual see the solenoid works.


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## SanderO (Jul 12, 2007)

Minnewaska said:


> Yes, they fail closed. If one leaves it open (on) permanently, they don't know it isn't stuck or there isn't a short that sends power, keeping it open, despite tripping the switch down below. Failsafe closed is more a comfort to know it won't reopen itself. I like to visual see the solenoid works.


I don't know for sure.... but I believe a solenoid is a relay which use electricity to magnetize a coil and mechancially close (in this case) a circuit which moves the valve to the open position. No power it "returns" to closed. The magnet coil can pull it open.

The starter solenoid closes the high voltage circuit to power the starter motor. When it fails your starter circuit cannot energize.


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## outbound (Dec 3, 2012)

I'm curious as well. Always thought there was a spring that held it the closed position. When energized the electromagnet moved and held it open. Hence no draw when closed and draw when open. 
https://b9i5f9p8.stackpathcdn.com/w.../How-normally-closed-solenoid-valves-work.png


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## boatpoker (Jul 21, 2008)

outbound said:


> So leaving the solenoid on isn't much of a concern.


Propane passing through the solenoid keeps it cool.

Suggest you put your hand on that solenoid after 15.minutes engaged without propane throughput. It may change your mind.


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## outbound (Dec 3, 2012)

So many things you don’t think get hot do. Even LEDs, phone chargers, inverters, computers....in fact any electrical device with any degree of resistance will heat some over time. Another reason to turn all snuff off when not in active use and be careful about what’s near it. My wife thinks I’m a nut as I follow her and turn snuff off she leaves on. The light switches for the hanging closets are on pressure switches but the lights in the frig and freezer aren’t. I’ve got her trained to not open the door to the frig unless absolutely necessary but rather open the top and reach down but not to make sure to turn off the light if used. That’s a double whammy. Heat in a box you’re trying to cool and more parasitic draw. Of course it’s light tight so you need to open it to check if light is off. 
People stress about propane, fuel and other flammables but think there’s more electrical fires than gas explosions. Wonder if statistics bear that out.


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## denverd0n (Jun 20, 2008)

outbound said:


> Always thought there was a spring that held it the closed position. When energized the electromagnet moved and held it open. Hence no draw when closed and draw when open.


That is correct. That is how they work, when they are working correctly. They CAN, however, get stuck in the open position. I had that happen quite a few years ago on a camper trailer that I had. It may be extremely rare, but it is not impossible.

Ever since then, like Minnewaska, I will periodically turn off the solenoid first, just so that I can see for myself that it really is stopping the flow of propane.


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## boatpoker (Jul 21, 2008)

outbound said:


> think there's more electrical fires than gas explosions. Wonder if statistics bear that out.


You are correct. The following is from BoatUS Magazine. Pay particular attention to the last paragraph.

BoatUS Magazine - One problem with a fire aboard a boat is that unlike a house where running across the street to escape the flames is an option, on a boat there's no place to go but overboard. Unfortunately, this violates the second rule of boating: Stay with the boat. Ironically, if enough of what the boat is floating on can be brought into the boat, the fire can usually be put out. This, however, violates the first law of boating: Keep the water outside the boat. 
Obviously, stopping fires from getting started in the first place is the best defense. our Marine Insurance claim contain hundreds of fire-related claims which Seaworthy editors have spent many hours analyzing. Here's a rundown:
1)AC and DC wiring/appliance 55%

DC shorts/wiring 30%
DC engine voltage regulator 12%
AC appliance/heater 4% shore power 4%
AC wiring/panel 2%
DC battery charger 2% 
AC power surge 1%
If you've noticed a lot of wiring and electrical articles in Seaworthy over the years, now you know why; the number one cause of fires on boats are DC wiring faults. In the last issue of Seaworthy, we talked about your boat's DC electrical system and the fact that the most common electrical problem was related to wires chafing. Many fires are started by battery cables, bilge pump wires, and even instrument wires chafing on hard objects like vibrating engines or sharp-edged bulkheads. Shore power can be a problem area as well; 11% of fires were started by the boat's AC system, frequently at the shore power inlet. A few fires every year are caused by AC heaters and other household appliances that were brought on board. Electrical fires can be hard to put out because the source of the heat (a shorted wire) can reignite the fire even after a fire extinguisher has been used, which is why your boat must have a main battery switch and/or AC breaker to turn off the boat's entire electrical system.

2) Engine/Transmission Overheat 24%
Engine overheat 19%
Turbocharger overheat 2%
Transmission overheat 2%
Backfire 1%
Nearly a quarter of boat fires (24%) were started by propulsion systems overheating. Most frequently, an intake or exhaust cooling water passage was obstructed causing the engine to overheat and begin to melt down hoses and impellers. These fires tended to be less serious, but because of the amount of smoke they made, they got undivided attention, especially since the smoke was coming from an area with flammable fuels. Often the fires were simply smoldering rubber until someone made the mistake of opening the engine compartment and allowing fresh air to enter. The best way to put out a fire that's in the engine compartment is to have an automatic extinguisher system do it for you. If you don't have an automatic system, the next best course of action is to shut down the engine and use an extinguisher in a fireport if your boat has one; if not, crack open the hatch and discharge the extinguisher. Keeping the water intake lines and especially the exhaust manifolds and risers free of obstructions (weeds in the intake, rust in the exhaust) and replacing worn pump impellers will prevent most overheating fires.

3) Fuel Leak 8%
This might be the worst kind of fire to have on a boat. Many boats carry over a hundred gallons of gasoline on board and burning fuel can be hard to extinguish (95% of fuel-related fires were caused by gasoline). Typical problem areas are fuel lines, connections on the engine itself, and leaking fuel tanks. Fortunately, the first warning sign is usually a gas smell that is easily detected by the average human nose-if you can smell raw gas, something's wrong. Several fires were started by carelessness around gasoline; cleaning engine parts with gas, overfilling a fuel tank, and installing non-ignition-protected parts. One fire started when a member poured gas down a carburetor to start the engine. The engine backfired and caught the overhead on fire; the member jumped off the boat and ran to his house carrying the gas can, spilling gas along the way. The fire department report noted a zigzag burn pattern on the lawn up to the member's front door. Fortunately, aside from some burned grass, there was no damage to the house (Claim #0009144). A gas leak has to be taken seriously since it has the potential to explode and destroy a boat - that's why it's critical to run the bilge blower for four or five minutes before starting the engine. Diesel is not immune from igniting either - one fire was started when a ruptured line sprayed fuel on a hot manifold.

4) Miscellaneous 7%
Some fires didn't fit into any category-misdirected flares during a fishing tournament, anchoring in the wrong spot during a fireworks display, a child playing with matches, and even a case of spontaneous combustion from linseed-soaked rags. The only fire that couldn't have been prevented by more care was one caused by lightning.

5) Unknown 5%
Occasionally, investigators can't determine the cause of a fire. Sometimes, boats are completely destroyed and sometimes they sink, making finding the cause impossible.

6) Stove 1%

Stove fires appear to be less common (1%) than in the past, probably due to fewer alcohol stoves being installed on new boats. Still, alcohol can be a dangerous fuel; though it can't explode, an alcohol flame is hard to see. One fire was started when a member tried to light the stove and gave up because he couldn't see the flame. Unfortunately, he had succeeded, but didn't realize it until he got a call from the fire department. Only one fire was started by propane; a portable stove fell off a counter and ignited a cushion.


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## MikeOReilly (Apr 12, 2010)

Thanks BP. I'd love to see similar data for back in the day when pressure alcohol were common. 

I used one for years with zero problems. But I come from a camping background where these types of stoves are common. I learned at an early age never to turn my back on one, or leave it unattended.


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## MarkofSeaLife (Nov 7, 2010)

Wow. So few Propane fire is surprising.

Thanks @boatpoker for that info 

Mark


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## Minnesail (Feb 19, 2013)

MarkofSeaLife said:


> Wow. So few Propane fire is surprising.
> 
> Thanks @boatpoker for that info
> 
> Mark


I know this has been shared several times before, but it's worth watching. And fun to watch, since there's an explosion at the end 

When Yachting Monthly tried to blow up their "Crash Test Boat" with a propane explosion they had a difficult of a time getting it to ignite.

Crash Test Boat - Gas explosion

YouTube: Yachting Monthly's Crash Test Boat - Explosion!

A gas explosion is what's called a low probability/high impact event.


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