On Board RV Generators

What is an onboard RV generator and how is it different from a portable unit?

An onboard RV generator is permanently mounted inside the coach (usually in a dedicated belly bay or generator compartment) and wired directly into the RV's AC distribution panel through a transfer switch. It draws fuel from the RV's own gasoline, diesel, or LP tank rather than a separate gas can, and it starts from the dash or interior switch. Onan is the dominant name in this category, with models like the QG 4000 (gas), QD 6000/8000 (diesel), and LP-fueled units sized for travel trailers and Class A motorhomes. For 30-amp and 50-amp shore power conversion needs, see our RV plug adapters collection.

How do I pick the right Onan generator size for my RV?

Size the generator to the load you actually need to run, then add headroom for startup surge. A single 13,500 BTU air conditioner pulls roughly 2,800 to 3,500 starting watts, so a 4,000-watt Onan QG 4000 handles one AC plus lights, fridge, and a microwave. Two roof airs or a residential refrigerator push you to a 5,500 or 7,000-watt unit, and 50-amp diesel pushers typically run the QD 8000 or 10000. Confirm your coach's existing generator wiring, transfer switch rating, and compartment dimensions before ordering, swapping a gas unit for diesel or LP is not a drop-in job.

Do you carry propane (LP) onboard RV generators?

Yes. LP-fueled Onan generators are common in travel trailers and fifth wheels that already carry propane for the furnace, water heater, and cooktop, since they let you run a single fuel source across the coach. We stock the LP variants alongside gas and diesel models, plus replacement carburetors, control boards, starters, and fuel solenoids for existing units. If your generator runs but the AC will not start, the fix is sometimes upstream of the generator itself, browse RV electronics for capacitors, soft start kits, and control boards.

Can I install an onboard generator myself, or does it need a tech?

Most DIY-capable owners can handle a like-for-like Onan replacement: pull the old unit on its slide tray, reconnect the fuel line, ground strap, AC output leads, and 12V start wiring, then bolt it back in. New installs or fuel-type changes are a different story, they involve cutting a vented compartment, routing exhaust clear of windows, tying into the fuel system, and adding a transfer switch. If you are sourcing parts for a self-install and need to confirm fitment or wiring, text or call our team at 817-984-1852 before you order.

What shipping should I expect on an onboard generator?

Complete Onan generator sets weigh 150 to 400+ pounds depending on output and fuel type, so they ship via truck freight to a commercial address or terminal, with liftgate service available at checkout. Smaller parts (control boards, carburetors, mufflers, air filters, oil filters) ship standard ground and qualify for free shipping on orders over $100. Lead times on new generator sets vary by manufacturer stock, current ETAs are shown on the product page.