CO alarm goes off with water heat on

[Mountain7]

Hi everyone,

So I bought my brand new 2021 Forest river Salem Cruise lite trailer and thought everything would be peachy but within the 2nd week the monoxide detector keeps going off and I pin pointed the problem to it only goes off when the water heater is turned on.

So my water heater only runs on propane. I have done the detergent test and not seen any leak on the outside. I am plugged in to electricity so don't think its a faulty power surge or battery related since it only goes off when the water tank is turned on.

I have also resealed the vents and cables of the water heater from outside using automotive sealant. I am unfortunately far away from any dealer or mechanic to come look at the problem.

Would appreciate any advice?

[5picker]

Is this when using the R/V closed up as in no windows or doors open?

Is there a slide near by that could be allowing gases in (bad seal) where the CO detector is located?

Is the alarm from CO or LP?
Many have indicator lights that tell you or a different audible sound.

Welcome to the forum. I see it is your 1st post.

[Mountain7]

Originally Posted by 5picker

Is this when using the R/V closed up as in no windows or doors open?

Is there a slide near by that could be allowing gases in (bad seal) where the CO detector is located?

Is the alarm from CO or LP?
Many have indicator lights that tell you or a different audible sound.

Welcome to the forum. I see it is your 1st post.

Thank you! Definitely new to this site and to the RV life.

So I almost always close all the doors and windows when I have the water heater running since the exhaust vents are right outside the door and the detector is very close to the door as well.

I'm not sure what you are referring to the "slide". I did seal the frame of the water heater from outside since I've seen from inside that you can see light and it wasn't sealed well.

Also I believe it is only CO detector part that is going off (turns red and beeps every few seconds), since there is a light for the propane on the detector which doesn't go off or do anything.

Last time it went off was 5 days ago after I sealed the vents and I thought I took care of the problem. Now I'm thinking it was windy and the gases were dissipating off. Yesterday was a nice sunny day with no wind and it went off again.

Running out of ideas what could be the cause of it for a new trailer. Was hoping it was just a faulty detector but it only goes off with the water heater on.

[Scrapper]

A slide / slide-out is a portion of your RV which can be extended outward allowing expanded living area.

Any time the gas is turned on at the tank there is a clear path to the 2-way refrigerator, furnace, cooktop/oven and water heater. The furnace and cooktop/oven are the two items which have the gas line connections inside the rv. Sometimes the water heaters lp supply line runs into the rv before being connected to the wh's gas valve and burner.

If you have only turned on the valves at the LP tanks when trying to use the water heater the gas may be leaking from a different appliance's supply line or connection. You need to check for leaks at every gas line connection to all the appliances.

Since you say the alarm only goes off when trying the wh have you tried leaving the gas turned on at the tank without operating the wh to see if the alarm still goes off?

[Mountain7]

Originally Posted by Scrapper

A slide / slide-out is a portion of your RV which can be extended outward allowing expanded living area.

Any time the gas is turned on at the tank there is a clear path to the 2-way refrigerator, furnace, cooktop/oven and water heater. The furnace and cooktop/oven are the two items which have the gas line connections inside the rv. Sometimes the water heaters lp supply line runs into the rv before being connected to the wh's gas valve and burner.

If you have only turned on the valves at the LP tanks when trying to use the water heater the gas may be leaking from a different appliance's supply line or connection. You need to check for leaks at every gas line connection to all the appliances.

Since you say the alarm only goes off when trying the wh have you tried leaving the gas turned on at the tank without operating the wh to see if the alarm still goes off?

Thank you for the response.

So I leave the gas tank outside connected and one of them open at all times until it runs out. My stove, furnace, water heater and stove (dual electricity/gas) run on propane. I didn't think to check the connections for the rest since the alarm hasn't ever gone off with the furnace or the stove being used.

Only time the detector has gone off is when I turn on the water heater switch on my panel. It doesn't do it right away either but after like 5-15min it goes off. And again not every time since it was working well for a few days on and off.

[Mike134]

Some how the exhaust from the heater is finding it's way back into the trailer. Wind direction seem to have an effect? How about are exhaust fans running so air/fumes are being sucked into the trailer?

[Mountain7]

Originally Posted by Mike134

Some how the exhaust from the heater is finding it's way back into the trailer. Wind direction seem to have an effect? How about are exhaust fans running so air/fumes are being sucked into the trailer?

Wind presence seems to definitely dictate whether the alarm goes off. Is there an exhaust fan for the water heater that I'm not aware of? I have not looked from the inside so much to see if the issue is from inside or not. I was hoping and assuming its from outside seeping to inside.

Is there a way to seal the vents from inside?

[Scrapper]

Originally Posted by Mountain7

Wind presence seems to definitely dictate whether the alarm goes off. Is there an exhaust fan for the water heater that I'm not aware of? I have not looked from the inside so much to see if the issue is from inside or not. I was hoping and assuming its from outside seeping to inside.

Is there a way to seal the vents from inside?

No, the exhaust from the WH is too hot for a fan. As far as sealing from the inside that will involve removing the WH so it will be quite a bit of work in a tight space. Your dealer will be better equipped to handle it since your rv is new. Until you get it fixed make sure there are no windows open near the WH.


Since I haven't seen it mentioned yet the CO/LP detectors are susceptible to cleaning sprays/solution, bug spray, hair spray, and even dog farts.

[Mike134]

Originally Posted by Mountain7

Wind presence seems to definitely dictate whether the alarm goes off. Is there an exhaust fan for the water heater that I'm not aware of? I have not looked from the inside so much to see if the issue is from inside or not. I was hoping and assuming its from outside seeping to inside.

Is there a way to seal the vents from inside?

The exhaust fan I was speaking about would be the bathroom or kitchen exhaust over the stove pulling in outside air when they run

[5picker]

Since you mention it is the CO part of the detector alarming and not the LP side and since you say it only goes off when using the water heater, you'll need to focus on why the exhaust from the water heater burner is getting back into the R/V.

As mentioned, look for something not sealed where the water heater mounts to the sidewall (you mentioned being able to see out past the water heater from inside) and also look for anything that could be sucking the exhaust fumes into the R/V. Also look to be sure nothing is blocking the water heater exhaust (wasp nests). Have you tried running the water heater with the door open and see if it still happens? Do you have an aftermarket screen over the water heater exhaust?

[mnoland30]

We had that problem on our houseboat when the wind was blowing directly into the water heater. It went away when the wind died down. If I were you, and it is at home, I'd use a 120 v CO detector from your house and see if it goes off. That will tell you if your detector is faulty. If you don't have one for your house, get one. It is cheap insurance. I had a co-worker that woke up with a terrible headache, called 911 and collapsed before she could tell them what was wrong. She survived, but it was a close thing.

[wboglejr]

I had the same problem in my previous trailer when the breeze was on the water heater side of the trailer. Eventually the dealer determined who ever installed the water heater at the factory did not install the butyl seal around the heater. This allowed the CO to enter the trailer even though everything else was caulked/sealed very well. Never had another problem once it was installed.

[RV Rockies]

Mountain 7,
Have you figured out the issue with the alarm keep going off when you water is on? I have similar issue with my 2017. Please share your solution if you have one. Thanks!