Most RV propane and carbon monoxide alarms are wired into the wall, so the replacement has to fit the same hole, the same screw pattern and the same 12 V wires. MTI Industries, the maker of Safe-T-Alert, publishes replacement charts for its own older models, for Atwood/Dometic alarms and for CCI Controls alarms. This guide puts those charts in one place, with a link to each current model. If your old alarm is not listed, the universal models with a trim ring at the end are the fallback.
Step 1: read the label on the old alarm
Turn off the 12 V supply, take the old alarm off the wall and note three things: the brand and model number, whether it detects propane only, CO only or both, and whether it sits on the wall (surface mount) or in a hole cut into the wall (flush mount). Also look for the date code. MTI says to replace any propane or CO alarm that is more than 5 years old, so an old alarm that "still works" is not a reason to keep it.
Older Safe-T-Alert models
These pairings come from MTI's product pages, its discontinued-models page and its Recommended Replacement Part Numbers sheet.
| Old Safe-T-Alert model | What it is | Current replacement |
|---|---|---|
| 20-441 (20 Series) | Propane, surface mount | 20-441-P (same alarm) or the 25-741 CO + propane alarm, which MTI says is the same size, shape and mounting |
| 30-441 (30 Series) | Propane, surface mount | 30-441-P or the 35-741 CO + propane alarm (same size, shape and mounting, per MTI) |
| 30-442 (30 Series) | Propane, flush mount | 30-442-P or the 35-742 CO + propane alarm, which MTI says replaces all 30-442 alarms without modification |
| 40-442 (40 Series, discontinued) | Propane, flush mount | 45-742 CO + propane alarm (MTI: replaces all 40-442 alarms) |
| 40-441 (40 Series, discontinued) | Propane, surface mount | 80 Series universal propane alarm with trim ring (MTI's listed alternate) |
| 65-541 and 65-541-R (discontinued) | CO, surface mount | 62-541 CO alarm |
| 65-542 (discontinued) | CO, flush mount | 62-542 with trim ring |
| 70-742 (discontinued) | CO + propane, flush mount | 25-742 with trim ring |
| 70-742-R-KIT (discontinued) | CO + propane with valve control | 25-742-R kit with relay, trim ring and solenoid valve |
The upgrade paths matter. MTI points out that many older RVs have a propane alarm but no CO alarm, and the 25, 35 and 45 Series combination alarms can add CO protection when the propane alarm is due for replacement; the chart above shows which ones MTI says fit the same spot.
Atwood and Dometic alarms
MTI's Cross Reference Replacements sheet lists these Atwood/Dometic models:
| Atwood / Dometic model | What it is | Safe-T-Alert replacement (MTI note) |
|---|---|---|
| 36681 | Dual LP/CO alarm, 12 V, white | 45-742-WT (same size cutout) |
| 31012 | Dual LP/CO alarm, 12 V, black | 45-742-BL (same size cutout) |
| 36720 | 12 V LP gas detector, white | 20-441-P-WT (mount sideways to align screw holes) |
| 31014, surface mount | 12 V LP gas detector, black | 20-441-P-BL (mount sideways to cover screw holes) |
| 31014, recess mount | 12 V LP gas detector, black, with recess bracket | 25-742-BL (mount sideways; MTI notes it can replace recessed installations without a bracket) |
MTI's 25 Series flush-mount product page also lists it as suitable for replacing Atwood models 31013 and 31014.
What about the Atwood 31011?
The Atwood 31011 CO and LP detector is not on MTI's cross-reference sheet, so we do not call any Safe-T-Alert model a direct replacement for it. You have two routes. If you want the same unit, we still sell the genuine Dometic Atwood 31011. If you want to switch, MTI says the universal mounting bracket on its Universal Alarms (the 80 and 85 Series) allows replacement of almost all alarms on the market, including Atwood and Dometic alarms, and the 85 Series universal CO and propane alarm comes with a trim ring that covers old screw holes and fits into the cutout of a previous alarm. Measure your old cutout first (see the Safe-T-Alert size guide) or send us a photo.
CCI Controls propane alarms
MTI's CCI cross list says these are direct replacements with no modifications needed:
- CCI 7770.231, 7770.281, 7773.081, 7773.151, 7773.231 and 7773.251: 30-442-P-BR
- CCI 7770.234 and 7770-284: 30-442-P-WT
- CCI 7770.244: 30-441-P-WT
MTI adds that its 30-442 can replace any flush-mount CCI model that does not use a valve, and that it can be installed vertically or horizontally. The 35-742 combination alarm replaces all CCI propane alarms that a 30-442 can replace, which adds CO protection in the same cutout.
Two wiring notes from the same MTI sheet. Some CCI units in Fleetwood and Winnebago RVs have two power leads; Safe-T-Alert units have one, so MTI says to connect the "House" power to the Safe-T-Alert red wire and cut and cap the "Chassis" wire. And never connect a Safe-T-Alert alarm to a solenoid valve controlled by a CCI propane alarm: MTI warns of a burn or fire danger and says the CCI alarm and valve must be replaced together.
No match? Use a universal model
MTI makes two universal replacements with a trim ring that covers existing screw holes and fits newer units into previous installation cutouts:
- 85 Series universal CO + propane alarm: upgrades a single propane alarm to a dual alarm. Size with trim ring 7 x 4 x 1 in.
- 80 Series universal propane alarm: propane only, for rigs that already have a separate CO alarm. Size with trim ring 7 x 4 x 1 in.
Frequently asked questions
Will a Safe-T-Alert fit my old wiring?
All the alarms in this chart run on the RV's 12 V DC supply (12 V plus or minus 15%), so no batteries are involved. Follow the wiring diagram in MTI's manual for your model.
Can I replace a propane-only alarm with a combination alarm?
Yes. MTI designs the 25, 35, 45 and 85 Series to upgrade a single 12 V propane alarm to one that detects both propane and CO. Check the chart above for the model that matches your old size and mounting.
Is the color important?
Only for looks. Most models come in white and black, and some in brown.
Which one replaces my Atwood 31011?
MTI does not list the 31011 on its cross reference. Buy the genuine 31011 if you want an identical swap, or measure the cutout and consider the universal 85 Series with trim ring.
Every Safe-T-Alert alarm we sell ships from our warehouse in Upland, California. Not sure which one replaces yours? Send us a photo of the old alarm and its label before you order and we will match it. Browse the full Safe-T-Alert range.