Buying, owning and maintaining a motorhome can feel like a bit of a minefield. Damp. Habitation checks. Lithium batteries. Solar. Winter storage. Expensive repairs you definitely didn’t budget for, there’s a lot to get your head around.
So, I sat down with Gary and Ryan from Onsite Caravan Services to put your biggest motorhome and campervan questions to two people who actually work on these vehicles every day.
Between servicing, repairs, electrical upgrades, air-conditioning installs and pre-purchase inspections, they’ve seen the good, the bad and the “how has that not caught fire yet?”
Here are the biggest takeaways.
1. What should you check before buying a used motorhome?
Start with the boring-but-important stuff:
- MOT history
- Base vehicle service history
- Evidence of regular maintenance
- Whether the vehicle’s weight works with your driving licence
- The overall condition of the habitation area
Don’t automatically be put off by age or mileage, either. A 10-year-old motorhome may only have done 10,000–25,000 miles, and a well-maintained older van can still be a very sensible buy. In fact, regular use can actually be a good sign. Appliances that sit unused for years can develop issues, while systems that are used and serviced regularly often fare better.
2. How do you spot damp?
Damp is arguably one of the biggest fears when buying a used motorhome, and rightly so.
But as Gary points out, don’t confuse damp with condensation. Condensation happens because of temperature differences. Water ingress is where water has found its way behind the wallboards, usually through window seals, rooflights, body joints, corner caps and cracked or failed sealant.
A professional damp meter is the best way to check properly, but there are a few obvious warning signs to look for:
- Staining inside cupboards
- Discolouration
- Soft or damaged wallboards
- Suspicious areas around corners and joins
Finding damp doesn’t always mean you should walk away. The problem is that a small visible patch can hide a much bigger issue behind the wall. If you spot it, pause the purchase, get a proper inspection and find out what the repair is likely to involve before negotiating.
3. Can you prevent water ingress?
You can’t guarantee a motorhome will never leak, but catching problems early makes a huge difference. Gary and Ryan recommend giving the exterior a proper once-over regularly, especially when washing it. Keep an eye out for:
- Cracks
- Gaps around windows
- Tired rooflight seals
- Body joints
- Areas where moss or water collects
A small issue caught early may only need a reseal. Leave it too long and you could be looking at internal repairs, wallboard replacement and a much bigger bill.
4. What does a ‘habitation check’ actually cover?
A proper habitation check is much more than a damp test. According to Gary and Ryan, it should cover the condition of the bodywork, signs of water ingress, professional damp readings, appliances and the key systems inside the motorhome, including:
- Gas
- 230V mains electrics
- 12V systems
- Heating
- Water systems
- Batteries
- Charging systems
- Inverters
- Appliance safety and operation
They recommend having one done annually, particularly if it’s needed to maintain a manufacturer warranty. A typical UK habitation check costs roughly £170 to £300, depending on the provider and location. When you consider the value of the vehicle, it’s a pretty small price to pay for peace of mind and a useful service record when you come to sell.
5. Is it easy to upgrade from lead-acid to lithium?
Potentially. But it’s not always as simple as swapping one battery for another. The battery itself might be easy enough to fit, but to get the best from lithium, you may also need to look at:
- Whether the mains charger is compatible
- Solar charge-controller settings
- DC-to-DC charging
- The correct lithium charging profile
Gary and Ryan are big fans of lithium because it offers more usable capacity and a longer lifespan than a traditional lead-acid leisure battery. It makes most sense if you spend time off-grid, but even more casual users can benefit from having more usable power available.
6. How much solar do you actually need?
There is no one-size-fits-all answer, as your ideal solar setup depends on a number of factors:
- How long you spend off-grid
- How much power you use
- The size of your battery bank
- Whether you run high-powered appliances
- How much roof space you have
As a general rule, if you can fit 300 to 400W of solar, it will obviously replenish a lithium battery much faster than a 100 to 200W setup. But don’t just chase the biggest number possible, it’s important you design a system around the way you actually travel.
If you spend every night on a campsite with hook-up, you probably don’t need a roof full of panels and a battery bank that could power a small village.
7. Rigid solar panels or flexible panels?
For most motorhomes, Gary’s preference is rigid solar panels.
Flexible or stick-on panels are improving and can make sense on campervans, pop-tops, curved roofs or where weight is a major consideration. But rigid panels have an advantage. The airflow underneath helps them stay cooler, which is generally better for performance.
8. What should you do before winter storage?
If you remember one thing from this entire blog, make it this: drain the water system properly. Frost damage is one of the most avoidable causes of expensive winter repairs.
Before storing your motorhome, Gary and Ryan recommend:
- Turning the water pump off
- Opening the drain or dump valve
- Opening taps and leaving them in the centre position
- Emptying the fresh-water tank
- Emptying the grey-water tank
- Emptying toilet-related water systems
- Isolating the gas supply
Any water left inside a tap, pipe or boiler can freeze, expand and cause damage.
Gary said they get plenty of calls in January about cracked taps and damaged boilers that could have been avoided with a proper drain-down.
9. Should you start the engine during winter storage?
Not just for the sake of it. Gary’s view was that starting the engine briefly, without getting it properly up to temperature, is not especially helpful.
If you’re going to start it, take it for a proper drive. Don’t simply let it idle for a few minutes in the hope it will put some charge back into the battery.
If your motorhome is stored outside, even a modest solar panel can help keep the leisure and starter batteries topped up, depending on the weather and any parasitic drain.
10. Can toilet fluid damage the flush pump?
Apparently, yes. Gary and Ryan regularly see toilet flush pumps get stuck or blocked because too much pink fluid has been used, or it has not been diluted properly.
The advice is simple: don’t just pour loads in and hope for the best. Measure it properly, use less than you think you need, or use clean water where the system allows. It is a tiny detail, but it could save you the cost of a replacement pump.
11. Which jobs should you leave to professionals?
Gas, 230V mains electrics and major 12V electrical work. These systems can become dangerous very quickly if you do not understand the regulations, cable sizing and installation requirements.
Gary and Ryan say they’ve seen DIY installs involving everything from incorrect cable sizes and overloaded wiring to loose electrical connections and ignition sources that are dangerously close to gas systems.
A 12V system might sound harmless, but a cable that’s too small for the current it is carrying can overheat and become a fire risk. If you’re in any doubt, get somebody properly trained and accredited to do the work.
12. How often should you test smoke and carbon monoxide alarms?
Every time you use the motorhome. Press the test button and make sure they work. Gary and Ryan also recommend carrying suitable fire-safety equipment onboard. It takes seconds and is one of the easiest checks you can make.
13. What is the best motorhome upgrade for £1,000?
Unsurprisingly, both engineers point towards electrics. Depending on the motorhome and how you use it, £1,000 could go towards:
- A lithium battery
- Solar panels
- Better charging
- Wi-Fi
- Other practical upgrades
You don’t always need to spend huge amounts to make a noticeable difference. The best upgrade is usually the one that makes your own trips easier, not the one that looks most impressive on a spec sheet.
14. Are underslung LPG tanks a good upgrade?
Gary was not particularly keen on them. His concern is that underslung LPG tanks sit beneath the motorhome, where they are more exposed to road debris, damage and corrosion. He also stressed the importance of having an isolation point that is easy to access and understand.
There are plenty of people who are happy with underslung tanks, but Gary’s preference is generally for alternative LPG arrangements where possible.
15. Is motorhome air-conditioning worth it?
For those heading into hotter parts of Europe, air-conditioning is a tempting upgrade.
Gary explains that roof-mounted air-conditioning units can often replace an existing 400mm x 400mm rooflight, although it depends on the vehicle and its wiring. One useful benefit is that the unit can be removable and transferable to your next motorhome, so it does not necessarily have to stay with the same van forever.
A professionally installed Truma system is estimated at around £2,000 to £2,500, although prices will vary.
16. Can you run air-conditioning off-grid?
Yes, but you need a seriously capable electrical setup. Most habitation air-conditioning units run on 230V, so you’ll typically need:
- A suitably sized inverter
- A substantial lithium battery bank
- Correctly sized cabling
- A way to recharge everything afterwards
Gary gives the example of a setup using two 600Ah lithium batteries, which calculations suggested could run air-conditioning for around eight hours. But once the battery power is gone, it needs replacing.
So, is it possible? Definitely. Is it cheap, simple or realistic for every motorhome? Not really.
17. Is a pre-purchase inspection worth it?
For me, this was probably the biggest takeaway from the conversation. A proper pre-purchase inspection is similar to a full habitation check and covers the things most buyers simply cannot assess properly on a viewing.
Take the fridge. You can turn it on during an inspection and still have no idea whether it works, because it may take hours to reach temperature.
Their tip is to ask the seller to have the systems running before you arrive. That way, you can check that the fridge is cold and the hot water is working. A replacement fridge alone could cost more than £2,000.
Onsite Caravan Services start with a damp test. If serious damp is found immediately, there may be little point paying for the rest of the inspection.
They have also seen buyers pay around £10,000 for motorhomes that turned out to be worth less than half that because of hidden issues.
Their advice was blunt: if a seller refuses an independent inspection, walk away.
18. What is the most overrated motorhome upgrade?
Over-speccing your electrical setup.
You can spend thousands on huge battery banks, inverters and solar systems. But if every trip involves a campsite with electric hook-up, you may barely use any of it. Build the motorhome around your travel style, not around the most impressive possible specification.
If you want to hear about the most overrated upgrades, you can watch the full video below.
19. What is the most underrated motorhome upgrade?
Ironically, the answer came back to lithium.
When it’s properly installed and suited to the way you travel, lithium can transform your usable battery capacity and make off-grid trips far easier. It’s not the right answer for everyone, but for people who regularly stay away from hook-up, it can be a genuine game-changer.
20. What’s the biggest mistake owners make?
Sometimes, it’s simply not understanding the vehicle.
Gary said a surprising number of call-outs are down to operator error. Modern fridges, heating systems, chargers and control panels can be complicated, so read the manuals and pay attention during the handover.
One brilliant tip: record the dealer handover on your phone. You will be grateful for it later when you are parked somewhere remote, staring at a control panel and wondering why nothing is working.
They also highlighted servicing requirements that owners may not know about. Some wet central-heating fluids, for example, need changing periodically depending on the system.
Final thoughts
If there is one message that came up again and again in this conversation, it was this: preventative maintenance is always cheaper than repairs.
Get the habitation check. Keep an eye on your seals. Drain the water system properly before winter. And please, do not take chances with gas or electrics just to save a few quid.
A motorhome is a big investment, and most of the expensive problems Gary and Ryan see could have been caught earlier, or avoided altogether. If you’re about to spend tens of thousands on a used motorhome, paying a couple of hundred pounds for an independent pre-purchase inspection is a no-brainer.
Gary and Ryan at Onsite Caravan Services offer habitation checks, servicing, repairs, upgrades and pre-purchase inspections locally.
