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Auto-Trail • Expedition Coachbuilt • 2026
Complete guide — 30 diagnostic faults and 26 FAQs across 7 categories, assembled from every category document and cross-referenced part covering this exact edition.
TrumaiNet X Panel / Truma iNet X Pro Panel
Control Panel (General)9006 FAQs
iNet X Panel / Truma iNet X Pro Panel
Control Panel (General)Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
Control unit cannot be switched on | The control unit cannot be powered on or started. | — | Check the 12 V power supply and inspect vehicle power supply fuses, replacing them if necessary. | DIY Safe |
Error messages (Appliance Error) | An error occurred in a connected appliance. | — | Follow the suggested solutions on the display and confirm the error using the control unit. | DIY Safe |
App issues | Connectivity or functional issue with the iNet X App. | — | Check that the application is updated to the latest version and perform an update if necessary. | DIY Safe |
Control panel won't switch on | Power supply issue or blown fuse. | — | Check power supply (12 V) and check vehicle power supply fuses, replacing them if necessary. | DIY Safe |
Connected appliance fault | An error has occurred in a connected appliance. | — | View suggested solutions on the display and follow the instructions to acknowledge and reset faults on the control panel. | DIY Safe |
App connection/operation problems | App version may be outdated or connection lost. | — | Make sure you're running the latest version of the app (update it if not), that Bluetooth is turned on, and that you're within range. | DIY Safe |
Control panel won't switch on | The control panel fails to power on. | — | Check the 12 V power supply. Check the vehicle's electrical power supply and replace the fuse if necessary. | DIY Safe |
Error warnings (on connected device) | An error has occurred in a connected device, showing suggested troubleshooting solutions on the screen. | — | Follow the instructions on the screen and acknowledge the error on the control panel display. | DIY Safe |
App issues | Issues or malfunctions relating to the mobile app connection or functionality. | — | We recommend checking for app updates and updating the app if necessary. | DIY Safe |
Frequently Asked Questions
Q: How does standby mode work?
If no input is made for 60 seconds, the display changes to the lock menu, and after a further 60 seconds, the display turns off to save power. It can be reactivated by briefly pressing the Home button.
Q: Can multiple mobile devices be connected via Bluetooth?
Yes - you can pair several devices, and up to 3 phones or tablets can be connected to operate it at once.
Q: How do I switch on the control panel?
Press the Home button briefly for 1 second. The start screen will open in the display, followed by the main menu.
Q: How do I switch off the control panel?
Choose 'Switch off' in the main menu, then 'Switch off' again in the submenu. Bear in mind this also turns off every heater and air conditioner connected to the panel.
Q: How do I connect my mobile device via Bluetooth?
Turn on Bluetooth on your phone or tablet, keep it within range of the control panel, and follow the display's setup wizard together with the app's instructions.
Q: What is the service life of the integrated battery?
Its built-in battery, which keeps your settings (time, language, appliance settings), lasts roughly eight years. A dealer can replace it if you ask.
Auto-TrailElectrical System (Expedition Coachbuilt, 2026 Model Year)
Electrical1001 FAQ
Electrical System (Expedition Coachbuilt, 2026 Model Year)
ElectricalMaster Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | Miniature circuit breakers (MCBs) cannot be reset | Something's gone wrong on that circuit, or it's carrying more load than it can handle. | Investigate the circuit for faults or overloads before attempting to reset. | DIY Safe |
Frequently Asked Questions
Q: Which fuse or MCB protects which circuit, and what rating should I use to replace one?
On the PSU (fuses 2 to 10 show a red LED beneath them once blown, while the charger's own fuse has a green LED to confirm it's working): Fuse 1 (25A, white) - Charger; Fuse 2 (7.5A, brown) - Permanent 12V; Fuse 3 (10A, red) - 12V Sockets; Fuse 4 (10A, red) - Appliances/Fans; Fuse 5 (15A, blue) - Compressor Fridge (when fitted); Fuse 6 (10A, red) - Pumps; Fuse 7 (10A, red) - Light Main & Dimmer 1; Fuse 8 (10A, red) - Light Main & Dimmer 2; Fuse 9 (5A, tan) - Awning/Entry Light; Fuse 10 (10A, red) - En Route/Electric Step; Fuses 11-13 (15A/7.5A/5A) - Spare; Fuse 14 (15A, blue) - Solar (rear fitting).
MCBs: MCB 1 (10A) - 230V sockets/cooker; MCB 2 (16A) - Extra 230V sockets/heating system; MCB 3 (10A) - Fridge/Separate Water Heater/Charger/Aircon. Always fit a replacement fuse rated the same as the original - never a higher one, since that risks damage to the wiring harness. If a new fuse blows again straight away, don't just keep swapping it out - get the underlying fault checked and speak to your dealer.
SargentAC-DC Battery Chargers
Standalone Battery Charger (Accessory)5005 FAQs
AC-DC Battery Chargers
Standalone Battery Charger (Accessory)Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | The electrical system shuts down by itself randomly. | Overvoltage - the Sargent system shuts down as soon as it detects more than 15V, usually because of a faulty solar regulator or a mains charger fault | To check whether the solar regulator's at fault, see if the random shutdowns only happen during sunny daytime hours when the regulator's actually active - disconnecting the solar input, or covering the panel, is a good way to test this. You could also measure the regulator's output voltage directly, though that reading can jump around depending on cloud cover. For the charger, a fixed-voltage type should never read above 13.8V; if you've got a PX300 fitted, its product page has a downloadable attachment for checking it's working correctly. | DIY Safe |
N/A | Battery is overheating and showing symptoms of being overcharged. | A failed cell within the lead-acid battery (turning it effectively into a 10V battery, causing it to draw more current and overheat under normal charge voltage). | Check the battery itself for a failed cell first. If you suspect the charger rather than the battery, see the separate troubleshooting for a PX300 that isn't working correctly. | DIY Safe |
N/A | Lithium battery has entered Deep Sleep mode (DSLP) with State of Charge reduced to 0% and output switched off. | The battery State of Charge has reduced to 0%. | Get the battery back on charge as soon as you can, since leaving it will shorten its lifespan and hurt performance. If it's gone into Deep Sleep, the Sargent PX310 charger's own 'lithium wakeup' feature may be able to rouse it and start charging normally - or you can briefly apply a fixed 12-15V across the terminals yourself. | DIY Safe |
N/A | Lithium battery has gone into Under Voltage Protection (UVP) after a cell dropped below 2.5V (or the terminals fell below 10V), cutting off output entirely | Critical low internal voltage of battery cells due to deep discharge. | Get it back on charge immediately - a fixed-voltage charger will bring the cells back up to the level at which they'll switch back on (2.8V per cell, or 11.2V total across four cells). Depending on how deeply discharged it is, this can take up to 30 minutes. | DIY Safe |
N/A | PX300 charger isn’t working correctly | — | Head to the PX300's product page, download the attachment linked there, and follow its instructions to check the charger's output voltages and confirm it's working properly. | DIY Safe |
Frequently Asked Questions
Q: What happens when the Sargent control system detects the battery State of Charge falls to 15%?
First, an alert appears on the control panel's screen, warning that the battery needs recharging.
Q: And if it's still not recharged and drops further, down to 5%?
The system alerts again, then switches off every circuit it controls to stop further discharge - though anything wired directly to the battery, bypassing the control system, will keep drawing current regardless.
Q: How can I extend the lifespan of a Sargent lithium battery?
Steer clear of frequent deep discharges, and try to keep it sitting at a partial charge - ideally somewhere between 40% and 80% - rather than running it right down. Don't treat Under Voltage Protection (UVP) kicking in as your cue to recharge; by then it's already past where you want to be.
Q: Can I fit a Lithium battery to my system?
Most Sargent systems use a PX300 or PF200 battery charger. If yours has a different charger fitted, check with that charger's own manufacturer for Lithium compatibility. The PX300's charging profile suits many leisure-industry Lithium batteries that have their own internal Battery Management System (BMS) - its charging profile and voltages are available as a downloadable attachment on the PX300's own product page, though you'll still need to confirm suitability directly with your chosen battery's manufacturer.
Systems that use a PX300 include the EC800, EC700, EC600, EC500, EC400 series, EC400+ and EC328. If your system doesn't have a PX300, its charger will run a fixed 13.8V, which generally isn't suitable for fully charging a Lithium battery - and switching to Lithium may also mean you need a DC-DC charger to keep the charging current within limits.
Q: Can I fit a different make of AGM battery?
We don't endorse any particular make or model, but the PX300 charger (fitted across the EC400/EC400+, EC500, EC600, EC700, EC800 and EC328 systems) suits the great majority of good-quality AGM batteries sold in the UK. Its charge profile is included in the instruction manual attached to its product page - if you're at all unsure whether a battery is compatible, check with that battery's own distributor or manufacturer first.
SargentEC700 Series Systems
Battery Charger / Power Management3007 FAQs
EC700 Series Systems
Battery Charger / Power ManagementTechnical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | EC700 or EC800 control panel's battery current reading doesn't look right | — | Switch the mains charger off at the EC700/EC800 PSU (skip this if you're not on a mains hook-up). Press and hold the cog (system settings) button to open advanced settings, then use the arrow to move to page 2 and press 'Calibrate'. A pop-up warns that the van's power will briefly cut out while calibrating - accept it, and the current sensor calibrates itself. Once power's back, the current reading should show correctly again. | DIY Safe |
N/A | Leisure batteries keep discharging, or don't hold their charge as long as they should | In the vast majority of cases, this comes down to a faulty or under-performing battery - even a brand new one can be the culprit. | Before testing, give the leisure battery a full charge of 24 hours or more, turn the charger off, disconnect or cover the solar panel so it can't affect readings, and disconnect the Stinger alarm if one's fitted - if two batteries are fitted, test them one at a time. To check the PSU's own draw, fit an ammeter or plug-in meter where the leisure battery fuse normally sits: with the PSU's shutdown button out the reading should be zero (anything else means extra equipment is drawing current and should be disconnected); with the button in, compare the reading against the system's published Power OFF figures; and with the button in and the panel switched on (everything else off), compare against the Power ON figures. To check the charger, note the battery voltage on the panel or at the terminals (expect around 12.7V, or 13-13.5V if recently charged), switch the mains charger on and watch the voltage rise and settle at 13.6V float, then switch on some lights and confirm it shifts to 14.4V. To check the battery's actual capacity, switch the panel on, turn on enough lights to draw about 5A, and time how long it takes to discharge down to 10V (when the panel warns and cuts the power) - multiply the discharge current by the elapsed hours to get the real Ah delivered, and repeat the test if the result looks low. A battery that keeps testing poorly should go back to its supplier or manufacturer for proper discharge testing. | DIY Safe |
N/A | Ammeter still shows a reading even with the PSU shutdown button pulled out | Something's been added to the system since the original installation and is drawing current that shouldn't be there | Disconnect this extra equipment. | DIY Safe |
Frequently Asked Questions
Q: Is it possible to charge the vehicle (starter) battery using my system?
Whether you can depends on which type of Sargent PSU system you have - manual-charging or CAN-bus based.
On systems that only charge manually - PSU2007 with EC200, EC328, EC325, EC225 with EC100, EC176 with EC361/2/3, and EC155 with EC50/51 - the leisure battery is charged by default: with the control panel switched off, the mains charger starts charging the leisure battery the moment it's plugged in, and with the panel on, it keeps the leisure battery topped up while also powering the leisure loads. To charge the vehicle battery instead, switch the control panel on and pick the vehicle battery - the charger then charges that battery along with any leisure loads left switched on. Note that EC100, EC200, EC325 and EC50/51 panels won't allow the vehicle battery to be selected below 10.9V, while EC328 panels (software V2.21) will allow it above 2V provided the mains charger is on. If mains power is lost while charging the vehicle battery, leisure loads will start drawing from it instead - switching back to the leisure battery once the vehicle battery either falls below the 10.9V cut-off or, if it started above that, once it recovers back up to 10.9V. The leisure battery itself has its own 9V cut-off that disconnects leisure loads to stop it discharging further.
CAN-bus systems (the EC800, EC700, EC600, EC500, EC450 and EC400) include a smart-charge feature instead, on by default but switchable off. With the mains charger on, it defaults to charging the leisure battery while keeping an eye on the vehicle battery - if that drops below 12.4V, charging switches to it for 4 hours, then returns to the leisure battery for another 4 hours, repeating the cycle for as long as the vehicle battery stays low. This runs regardless of whether the control panel is on, as long as the system's own shutdown button is switched in (unless you've disabled the feature) - and if the panel is on, you can manually pick whichever battery you want charged at any point in the cycle.
Q: How do I calibrate an EC700 control panel?
Start by switching the EC700 PSU off, then switch the shutdown button on again while continuously tapping the control panel screen. Once the system powers up you'll see a blue screen prompting you to touch 3 dots - do that, and the panel will show 'calibrated' on the blue screen, then go back to its usual display, completing the process.
Q: How do I calibrate an EC800 control panel?
Start by switching the EC800 PSU on and powering up the control panel via its power button. Then press and hold that power button - after 5 seconds the screen goes off, but keep holding for another 15 seconds until a blue screen comes up asking you to tap 3 dots. Do that, and the panel will show 'calibrated' on the blue screen, then go back to its usual display, completing the process.
Q: Can I fit a Lithium battery to my system?
Most Sargent systems use a PX300 or PF200 battery charger. If yours has a different charger fitted, check with that charger's own manufacturer for Lithium compatibility. The PX300's charging profile suits many leisure-industry Lithium batteries that have their own internal Battery Management System (BMS) - its charging profile and voltages are available as a downloadable attachment on the PX300's own product page, though you'll still need to confirm suitability directly with your chosen battery's manufacturer.
Systems that use a PX300 include the EC800, EC700, EC600, EC500, EC400 series, EC400+ and EC328. If your system doesn't have a PX300, its charger will run a fixed 13.8V, which generally isn't suitable for fully charging a Lithium battery - and switching to Lithium may also mean you need a DC-DC charger to keep the charging current within limits.
Q: Can I fit a second leisure battery to my Auto-Trail motorhome?
On an Auto-Trail, adding an extra leisure battery is normally simple - every current model and most older ones already have a dedicated connector, so the extra battery harness just plugs in.
Ideally pick a second battery of the same make, type and capacity as the one you have. If that's not possible, at least keep the capacity the same and never mix battery types (for example, don't pair a 'wet' battery with an AGM one).
Sargent sells the harness through its web shop (https://sargentltd.co.uk/shop/product/auto_trail_additional_battery_harness_2011-2016/229). It's the newer type, fitted to Auto-Trail vans from 2011, but it suits older vans too because the battery connector hasn't changed.
To fit it:
- Connect the harness to the new battery, making sure both terminals are tight and their covers are back on.
- Secure the battery in its box or compartment (this varies by year and model) without trapping the harness.
- Take the protective cap off the vehicle's spare battery connector.
- Plug the new battery in.
With an EC328 or EC700 system, that's it - the extra battery is ready to charge and use.
With an EC500 and the EC480 colour LCD panel, also set the battery size to the new total in the advanced settings (two 100Ah batteries means 200Ah), then recalibrate the current sensor.
To change the battery size:
- On the home screen showing the brand logo, press both the up and down arrows at once and keep them pressed.
- Let go once the screen changes.
- Scroll to 'Battery Size' and use select to raise it to the new total.
- Go back up to 'Exit Advanced', then press select to return to normal use.
Don't worry if the Ah reading drops afterwards - it takes a few charge and discharge cycles to line up with the real capacity, which is normal.
To recalibrate the current sensor:
- Turn the charger off, and switch the control panel off at its power button.
- Go to the active battery screen.
- Hold select until 'calibrating please wait….' appears.
- Let go - calibration is done.
Q: Can I fit a different make of AGM battery?
We don't endorse any particular make or model, but the PX300 charger (fitted across the EC400/EC400+, EC500, EC600, EC700, EC800 and EC328 systems) suits the great majority of good-quality AGM batteries sold in the UK. Its charge profile is included in the instruction manual attached to its product page - if you're at all unsure whether a battery is compatible, check with that battery's own distributor or manufacturer first.
Q: Can I connect additional solar panels to my system?
How much solar you can add through the PSU comes down to the fuse protecting that circuit, which varies by system - the maximum recommended wattage through the PSU is 120W for EC325/EC328/EC500/EC600, 80W for EC400, and 150W for EC700/EC800/EC400+. You can go beyond that by wiring extra panels straight onto the leisure battery via their own regulator and a correctly-sized fuse, though you'll lose the ability to see that extra solar's output on the control panel.
Any system without a PSU solar input at all needs its solar wired directly onto the leisure battery this way regardless - and there's no upper wattage limit when connecting straight to the battery like this.
Auto-TrailGas Supply System (Expedition Coachbuilt, 2026 Model Year)
Gas Regulator / Supply1001 FAQ
Gas Supply System (Expedition Coachbuilt, 2026 Model Year)
Gas Regulator / SupplyMaster Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | Burner accidentally extinguishes on gas hob, oven, or grill | — | Turn the knob back to O and wait a minute before trying to relight the burner. If it still hasn't caught within fifteen seconds, turn the knob back to O again, let go, wait another minute, then start the whole lighting sequence over. | DIY Safe |
Frequently Asked Questions
Q: How do I connect and change a gas cylinder?
Make sure you're using the right high-pressure hose for your cylinder type, and that the connector's sealing washer is fitted and properly compressed. Put out any naked flames nearby, secure the cylinder in its compartment and tighten the retaining straps, then fit the high-pressure hose to the cylinder with a suitable tool before turning the cylinder valve on.
TrumaCombiNeo 4 (E) / CombiNeo 6 (E)
Heating System (Space/Water)6004 FAQs
CombiNeo 4 (E) / CombiNeo 6 (E)
Heating System (Space/Water)Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
Appliance will not start | Gas supply disrupted or air in the gas line. | — | Confirm the gas cylinder and shut-off valves are open. It may take several attempts to draw gas fully through to the appliance. | DIY Safe |
W434H | Air bubbles have stopped appearing in the water container. | — | Switch off pressure pump, open FrostControl manually for about 15 seconds to drain approx. 2 litres of water, close FrostControl, switch pump back on, open hot water tap to bleed air, and wait briefly for the air bubble to rebuild. | DIY Safe |
Water's running straight back out - the water container won't fill | FrostControl is open. | — | Close FrostControl. | DIY Safe |
The water container won't drain even with FrostControl open | Bottom outlet of FrostControl or L-piece blocked, water pipe frozen, or aeration system blocked. | — | Check openings for dirt, slush, ice, or leaves and remove; thaw frozen water pipes; check venting hose for kinks or blockages. | DIY Safe |
Water drips/flows from elbow connection valve into venting hose | The elbow connection valve is scaled up or dirty. | — | Descale, clean, or replace the elbow connection valve. | DIY Safe |
Water is dripping/flowing from FrostControl floor outlet | Water pressure too high. | — | Check the pump pressure doesn't exceed 2.8 bar / 280 kPa, fitting a pressure reducer if it's on mains water. | DIY Safe |
Frequently Asked Questions
Q: Can the CombiNeo be operated while driving?
Yes, operation while driving is permitted provided that national regulations and rules are followed, and an appropriate safety shut-off device (such as Truma MonoControl CS or DuoControl CS) is installed.
Q: Why does FrostControl open automatically?
FrostControl opens automatically at temperatures below approximately 3 °C to protect the water system from frost damage, or in the event of overpressure in the system.
Q: How do I deal with winter operation using gas?
For operation at temperatures below 10 °C, propane must be used because butane stops vaporizing at around 0 °C.
Q: How often must the water container be descaled?
Descale the water container once a year, or whenever the control panel prompts you to.
Auto-TrailSmoke & CO Alarms (Expedition Coachbuilt, 2026 Model Year)
Smoke / CO Alarm3000 FAQs
Smoke & CO Alarms (Expedition Coachbuilt, 2026 Model Year)
Smoke / CO AlarmMaster Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | The smoke alarm gives a brief beep every minute. | The battery is worn out and needs replacing - the low-voltage warning will keep sounding for about seven days. | Replace the battery immediately. | DIY Safe |
Recommended partsAffiliate linksView 2 optionsHideCheck which battery your smoke alarm takes (look at the battery fitted now), then choose the matching one: The handbook says the smoke alarm is battery-operated but doesn't name the battery type, so check yours before ordering. 9V batteryDuracell Plus 9V Alkaline Batteries (2 Pack) 6LR61~£6.50 for 24.7★ (15,000+ ratings), dispatched/sold by Amazon View on Amazon →AA batteriesDuracell Plus AA Alkaline Batteries (12 Pack) 1.5V, LR06~£9.00 for 124.7★ (71,000+ ratings), dispatched/sold by Amazon View on Amazon → | ||||
N/A | The smoke alarm's LED doesn't blink once a minute as it normally would. | Battery is completely flat | Replace the battery immediately. | DIY Safe |
Recommended partsAffiliate linksView 2 optionsHideCheck which battery your smoke alarm takes (look at the battery fitted now), then choose the matching one: The handbook says the smoke alarm is battery-operated but doesn't name the battery type, so check yours before ordering. 9V batteryDuracell Plus 9V Alkaline Batteries (2 Pack) 6LR61~£6.50 for 24.7★ (15,000+ ratings), dispatched/sold by Amazon View on Amazon →AA batteriesDuracell Plus AA Alkaline Batteries (12 Pack) 1.5V, LR06~£9.00 for 124.7★ (71,000+ ratings), dispatched/sold by Amazon View on Amazon → | ||||
N/A | The carbon monoxide detector gives one audible chirp every minute, and can continue doing so for up to 30 days. | Incorrect settings found by the continuous sensor/circuitry check or low batteries | Check detector settings or change the batteries. | DIY Safe |
Auto-TrailToilets & Sanitation (Expedition Coachbuilt, 2026 Model Year)
Toilet0001 FAQ
Toilets & Sanitation (Expedition Coachbuilt, 2026 Model Year)
ToiletFrequently Asked Questions
Q: How do I prepare the Thetford cassette waste-holding tank before using the toilet?
Take the waste-holding tank out through the service door, stand it up so the pour-out spout faces upward, then take the cap off. Add the recommended amount of Thetford waste-holding tank additive plus roughly 3 litres of water so the bottom is covered, refit the cap, and slot the tank back into place.
Auto-TrailWater System (Expedition Coachbuilt, 2026 Model Year)
Water System Component2001 FAQ
Water System (Expedition Coachbuilt, 2026 Model Year)
Water System ComponentMaster Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | The water pump keeps running for more than 5 to 10 seconds after every tap has been shut off. | Possible leak in the water system | Check the system for leaks immediately. | DIY Safe |
N/A | Aerated water from a tap | There may be a leak on the pump's suction side. | Look for a leak where the pump draws water in and repair as needed. | DIY Safe |
Frequently Asked Questions
Q: How do I drain down the water system for winter or storage?
Open the fresh water tank's drain valve, then the wastewater tank's (into a suitable container), then leave every tap inside the vehicle open (mixer taps set to their central position). There's also an internal drain valve that clears the water heater and its own pipework - open that too, give the vehicle five minutes to finish draining, then briefly run the pump to clear any water left in it. Empty the cassette toilet too.
