Electrical and Systems
RV LP, Smoke and Carbon Monoxide Detector Replacement
Typical range
$200 to $600
Shop hours
1 to 3
Labor rate
$260/hr
The short answer
Detector replacement covers expired LP, smoke, and carbon monoxide alarms, including hardwired 12V units and the wiring behind them. Work runs $200 to $600, or 1 to 3 hours at $260 per hour plus detectors. Every unit carries a manufacture date and an expiration that owners rarely check.
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What this work actually involves
Every detector in an RV expires. LP detectors are generally rated for five years from the date of manufacture, and smoke and carbon monoxide alarms for seven to ten depending on the unit. The sensing element degrades whether or not the alarm has ever gone off, and an expired LP detector fails in both directions: it nuisance alarms at nothing, and it will not reliably alarm at real gas. Owners pull the fuse to stop the chirping, which is how a coach ends up with no gas detection at all.
Southern California conditions shorten that life further. Heat above 115 degrees in Palm Springs and Indio ages the sensing element faster than the rating assumes, and coastal salt air in Long Beach and Oceanside corrodes the contacts on the 12V feed behind the unit. The most common thing we find when a detector will not stop chirping is not the detector at all, it is a corroded or loose connection behind it delivering marginal voltage.
Placement matters and is frequently wrong on older or remodeled coaches. LP detectors go low because propane is heavier than air, carbon monoxide detectors go at breathing height, and smoke detectors go high and away from the galley so they are not triggered by cooking. When we replace detectors we also check that they are where they belong, since interior remodels routinely leave an LP detector mounted at eye level where it is close to useless.
The sensing technology also decides what each unit can honestly tell you. An LP alarm uses a heated metal oxide element that reacts to a broad family of combustible gases, which is why hairspray, aerosol cleaners, and a cooler of overripe fruit will all set one off. A carbon monoxide unit uses an electrochemical cell that consumes its electrolyte on a clock whether or not it ever encounters CO. Neither element can be verified by the button on the front, since that button proves the horn and the circuit and nothing else. The date code is the only honest verification, which is why we record it rather than pressing test and calling the coach good.
Location: All work is performed at our Yorba Linda facility. We do not offer mobile, roadside, or fleet route service.
02
What the job includes
- LP gas detector replacement with date coded units
- Smoke alarm replacement and correct placement away from the galley
- Carbon monoxide detector replacement at breathing height
- Combination CO and LP unit replacement where the coach uses one
- 12V hardwired feed testing and corroded connection repair behind the unit
- Mounting location correction where a remodel left a detector in the wrong place
- Detector circuit fusing and parasitic draw verification
- Function testing of every unit before delivery
- Documentation of manufacture and expiration dates on the invoice
- Propane leak testing at appliance connections before a chirping alarm is blamed on the unit
- Battery replacement and terminal cleaning on standalone units that are not hardwired
- Fire extinguisher condition and mounting check while we are in the coach
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When you need this service
- A detector chirping or alarming with no gas or smoke present
- A unit whose date code is more than five years old for LP or ten for smoke
- A detector that has been disabled, taped over, or had its fuse pulled
- Yellowed, cracked, or heat discolored detector housing
- No alarm response when the test button is pressed
- An LP detector mounted high on a wall instead of near the floor
- An alarm that sounds whenever aerosols or cleaning products are used inside
- A carbon monoxide unit that has been in place since the coach was built
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How we do it, step by step
- 01
Inventory and date check
Every detector located and its manufacture date recorded. Most coaches we see have at least one unit years past its rated life, and owners are rarely aware detectors expire.
- 02
Placement verification
Locations checked against how each gas behaves. LP goes low, carbon monoxide goes at breathing height, and smoke goes high and clear of the galley cooking area.
- 03
Power and wiring check
The 12V feed behind each hardwired unit tested for voltage and corrosion. A marginal connection causes nuisance chirping that gets blamed on the detector itself.
- 04
Gas system verification
Before a chirping LP alarm is condemned, the propane system gets a pressure decay test. Replacing a detector that is correctly reporting gas is the most expensive possible way to ignore a real leak, so the gas comes first.
- 05
Replacement
Date coded units installed, relocated where placement was wrong, and connections rebuilt with sealed terminals rather than reused corroded ones.
- 06
Function testing
Each unit tested for alarm function and, on hardwired units, verified to hold correct voltage with the coach on battery power alone.
- 07
Documentation
Manufacture and expiration dates for every installed unit written on the invoice so the next replacement interval is on record rather than forgotten.
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Pricing and posted rates
| Item | Rate or range | Notes |
|---|---|---|
| Typical job range | $200 to $600 | Varies with extent of damage and parts availability |
| Shop hours | 1 to 3 | Quoted after teardown, not before |
| Mechanical and electrical labor | $260 per hour | 2026 posted rate |
| Parts | 100% markup under $100, 35% over | Special order parts require a non refundable deposit at order |
| Deposit | 50% at authorization over $2,000 | Additional 25% when parts arrive on jobs over $10,000 |
| Sales tax | 7.75% on parts and materials | Labor is not taxed |
Insurance billed jobs may be billed at carrier negotiated labor rates that differ from the posted retail rates above. See all posted rates.
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Vehicles we do this work on
Vehicle
Class A Gas Motorhomes
A Class A gas motorhome is a flat-front coach built on a Ford F53 or Workhorse front-engine chassis, typically 28 to 38 feet. Rear
Vehicle
Class C Motorhomes
A Class C is a coach body built onto a cutaway van chassis with a sleeping or storage cabover extending above the factory cab. Tha
Vehicle
Travel Trailers
A travel trailer tows from a ball hitch behind the tow vehicle rear axle on an A-frame tongue, which makes it the most sway-prone
Vehicle
Standard Fifth Wheels
A fifth wheel couples to a hitch in the truck bed through a kingpin and pin box, with a raised forward bedroom over the truck. The
Vehicle
Truck Campers, Slide-In
A slide-in truck camper sits in a pickup bed and is clamped down at four points, so it absorbs the truck frame twist directly. Jac
Vehicle
Camper Van Conversions
Camper van conversions are Sprinter, Transit, or ProMaster chassis with windows cut into the sidewalls, a roof full of penetration
Vehicle
Park Model RVs
A park model is a towable unit up to roughly 400 square feet built with residential windows, roofing, and finishes, designed to si
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Questions about lp, smoke and co detector replacement
Frequently asked questions
Do RV detectors really expire?
Yes. LP detectors are generally rated five years from the manufacture date and smoke and carbon monoxide units seven to ten. The sensing element degrades on a clock, not on use. An expired LP detector both nuisance alarms and fails to detect real gas, which is the worst possible combination in a sealed coach.
How much does detector replacement cost?
Work runs $200 to $600, or 1 to 3 hours at $260 per hour plus detectors. Replacing a single LP detector at an existing location with sound wiring is at the low end. Replacing LP, smoke, and combination CO units, relocating two of them, and repairing a corroded 12V feed is at the high end.
My LP detector chirps constantly. Is it bad gas or a bad detector?
Test the gas first, always. If the system passes a manometer decay test, the chirping is either an expired unit or a marginal 12V feed behind it. Corroded connections are extremely common in coastal stored coaches and they produce exactly this symptom. What you should never do is pull the fuse and drive on.
Where should each detector be mounted?
LP detectors go within a few inches of the floor because propane is heavier than air and pools low. Carbon monoxide detectors go at roughly breathing height since CO mixes with air. Smoke alarms go high and away from the galley so cooking does not set them off. Remodels frequently leave these in the wrong places.
Can I just buy a detector and swap it myself?
On a standalone battery unit, sure. On a hardwired 12V LP detector it deserves more thought, because the fault we find most often is not the alarm at all but the feed behind it, and swapping the unit without testing the circuit hangs a brand new alarm on the same marginal connection. Mounting height has to be right as well, and many replacement units are not dimensionally identical to what came out, which leaves an opening in the wall panel that has to be closed properly rather than covered.
What happens if a detector alarms while my coach is in your shop?
We treat it as real until proven otherwise. An LP alarm gets a gas system check before anything is replaced. A carbon monoxide alarm gets the coach opened up and the combustion appliances shut down while we look for a source, which in an RV is usually a generator exhaust path, a furnace combustion chamber, or a water heater flue. Neither one gets silenced and handed back to you. If it turns out to be a genuine fault, we document what we found and what it took to clear.
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Ready to move on lp, smoke and co detector replacement? Bring it to Yorba Linda.