Propane alarm when using water heater

[jdoyle2141]

I have a Rockwood 1970ESP pop-up camper with a 6 gallon Suburban propane water heater.

In windy although I would say moderately windy conditions when I turn on the water heater I get a propane LP alarm. I've tried other appliances stove and furnace in same conditions no alarm so its definitely the water heater and it only happens when its on. That is it can't be the gas connection to the valve since that would always be alarming. Has to be something on the heater side of the valve.

I also used a step stool leaning against the side of the camper to shield the exhaust and problem went away.

Any ideas? Both Suburban and the dealer seem to think its somehow normal. I don't.

[jdoyle2141]

Upon further investigation, the door frame is supposed to be sealed with caulk on all 4 sides to the heater assembly. This would prevent unburned propane from getting pushed back into the cabin.

I am going to seal the other 3 sides, should be warranty but I wouldn't trust my dealer to change a light bulb, and give it a try. I will also make an external windshield for the exhaust.

I don't keep the water heater on all the time, really just to wash dishes but don't want to forget to turn off when its calm and then have an issue later when it gets windy.

[Bama Rambler]

I don't think it's normal, but it's possible that unburnt LP is getting into the RV from the exhausted gases. Especially during windy conditions, when the wind is blowing in the right direction.

Where is the LP alarm in relation to the water heater?
Have you checked the seal around the water heater to make sure it's sealed all around?

[jdoyle2141]

If you look at the design the only unburnt propane available is coming right out the inlet valve through a small opening in the tube to mix with air and then into the burner which is completely shielded. The burner was not being blown out thus there was no shutoff due to the flame sensor not being satisfied.

The only way it can get in is around the frame as far as I can tell. And the propane alarm is in the same cabinet right next to the water heater.

Haven't done this yet. I just used the step stool as a shield during the trip. But definitely not normal. The campground was full of campers with their water heater vents exposed to the wind (breezy but not wind advisory windy) and mine was the only alarm, at least out of the four folks who I polled. Two of whom had the exact same water heater.

I'll re-seal and try out soon and post the results.

Seems like a Rockwood screwup on installation.

[Reverse_snowbird]

I think you need to talk to this poster who has the same problem with a Rockwood water heater with the propane detector located near the water heater. Looks like it might be an installation problem.
https://www.forestriverforums.com/fo...ms-251467.html

[jdoyle2141]

Read this. He’s having a CO alarm I’m having an LP alarm. But in either case wind blowing into the heater has the possibility of blowing gas, LP or CO, back into the cabin if it’s not sealed properly. Easy to reseal so I’ll give it a try

[Reverse_snowbird]

The fact that you're both having trouble with wind and the water heater caught my attention. His CO detector is next to the propane detector.
Let us know how it goes.

[chriscowles]

Originally Posted by Reverse_snowbird

The fact that you're both having trouble with wind and the water heater caught my attention. His CO detector is next to the propane detector.

Let us know how it goes.

Having done nothing to change how the water heater works, nor changed any way it's ventilated or sealed, I'm sure all problems are due to incomplete ignition and raw propane circulating into the interior.

While I believe the alarms were CO, I cannot be certain. My wife does describe having smelled propane.

The confusion as to the cause of the alarm is why I'm replacing them with a separate LP alarm and a combination CO/smoke alarm.

[chriscowles]

I have a LP-only alarm on order. I need to buy a battery-operated combination CO/smoke alarm to replace the CO sensor. I bought a Kidde alarm at HD only to find in the instructions that it "isn't suitable for RVs or boats".

I spoke to Kidde tech support and was told the issue is sensitivity, that their RV (smoke-only) alarm is less subject to false alarms. Also, it's not available as a combination.

I already have a working smoke alarm. Since (according to Kidde) I can't buy a combination alarm intended for an RV, I might as well just buy a separate CO alarm. Can someone recommend one?

Does anyone have a combination that doesn't give them false alerts? The voice feature would be nice to help distinguish the source of the alarm but I don't want to pay double for that. (I guess separate CO and smoke alarms would make that obvious.)

[LukeGvRw]

Sorry for the late response here folks, I get way behind on reading the FR Forum. But this thread caught my eye because of similar problems with wind and CO detector (in our case) alarming. We have a Viking 17BH TT with the Suburban gas fired hot water heater installed under one of the dinette benches. The combination CO/LP on board detector is mounted on the outside of the seat compartment -so it is in the camper cabin. Almost as soon as we bought the camper in 2019 we started having CO alarms. It took a while to figure out it was happening anytime the wind (gentle or brisk) was blowing against the side of the camper where the water heater vented. My dealer tried to add sealant around the heater edges to no avail. At first they didn't believe it was happening until I bought a separate CO detector and put it under the seat. It went up to over 900 ppm (400 will kill you in about an hour). I finally called the manufacturer who agreed I needed a new hot water heater which they provided under warranty, including installation. We used the new water heater first time this season and second trip with wind the CO goes off! So here we go again. Supposedly, the manufacturer examined the original water heater but not sure they will be willing to explain how combustion gases were getting from the burner into the seat compartment/cabin. I suspect some kind of design or assembly flaw.

[Chris61]

Suburban Hotwater systems in Australia had a recall on their products and their licence was suspended because of a manufacturing problem

https://rvdaily.com.au/suburban-in-h...m08Lkiu6bYp16A

The problem has only just been rectified. They are the same unit as used in USA except for a different electric element. We use 240v, you use 120v

[LukeGvRw]

Hi Chris61, thanks so much for posting your reply with the Suburban recall info. If nothing else it validates that our problem is not an imaginary one! My model number (SW6D) is not specifically noted (SW6DA is) and it is only gas fired (no electric element) so may not be exactly like the ones recalled in Australia. (Unless the "A" just designates the same model released in Australia??) In any case, it certainly makes me more suspicious that there is an ongoing design or manufacture flaw once again in the replacement unit our dealer installed. To be sure, I will be following up on this even to our U.S. Consumer Product Safety Commission if I have to. Thanks again my friend!

[jdoyle2141]

The AU problem is almost 2 years old. Any update on cause and resolution?

[jdoyle2141]

As I had previously posted I suspected the heater was not properly sealed, presence of caulk on the bottom edge of the frame but none on the other three sides.

I caulked the other three sides of the frame and just got back from a 5 day trip. No alarms.

It was not a lakeside site and it was not quite as windy as my previous situation but still it was pretty breezy.

Some differences with problems other folks had. Mine is a propane alarm not a CO alarm. It doesn't happen all the time only when windy.

My theory is that when wind hits the water heater side through the exhaust grill it hits the burner heat shield. Note the combustion side (CO) is shielded from side winds and the exhaust is directed upwards.

The propane feed side is behind a louvered intake grill but is not otherwise shielded and there is an open part of the feed tube that is designed to mix propane with air. Wind could deflect off the heat shield and push propane through the unsealed opening into the cabin.

Time will tell. I'm thinking we'll be lakeside in September. I'll update.

[Chris61]

What are the defects?
The flange securing the burner heat exchanger tube to the internal front fascia of the appliance may not be properly formed. During use on gas, hot water services with the defect may emit carbon monoxide into the caravan or motor home.
What are the hazards?
If the unit is powered by gas and is operated in an enclosed area – such as caravan or motorhome - carbon monoxide may spill into the vehicle and poisoning could occur resulting in serious illness, injury or death.

https://www.productsafety.gov.au/rec...ca-and-sw6deca

Not sure if this applies to USA models, but there is a possibility

[sbjenni]

Just wondering if jdoyle2141 or anyone else has an update for this thread(?) I'm having a similar problem with the Suburban water heater in my Flagstaff T12RB PUP, but with one difference: The flame actually goes out in windy conditions and this triggers an ignition cycle, complete with gas line purge. And I'm reasonably certain its the repeated ignition cycle purges that causing a gas accumulation that is setting off the propane alarm in my case. But why is the burner so susceptible to wind? Or is it the exposed gas jet stream into the burner tube that's being deflected by wind? Meanwhile, has anybody figured out a successful design for a wind deflector for the outside vent?