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The Porta Potti 365 adds a piston flush and a waste-tank level indicator to a package with the same published tank capacities and seat height as the 165. Choose the 165 when a simpler bellows flush suits you; choose the 365 when those operating features justify the price difference you find.
Table of Contents
Compare the specifications that matter
| Feature | Porta Potti 165 | Porta Potti 365 |
|---|---|---|
| Flush mechanism | Bellows pump | Piston pump |
| Waste-level indicator | No | Yes |
| Waste tank | 21 litres | 21 litres |
| Flush-water tank | 15 litres | 15 litres |
| Seat height | 408mm | 408mm |
| Overall H × W × D | 414 × 383 × 427mm | 414 × 383 × 427mm |
These figures come from Thetford’s portable-toilet specifications. Retailer fields sometimes vary, so confirm the model and use the matching manufacturer information when space is tight.
Try the two flush actions
The 165’s bellows is pressed to pump rinse water. The 365’s piston uses a pull-and-push action. Both are manual systems, so neither needs a charged battery for flushing.
The 100-series support and 300-series support explain operation and care. If hand comfort is an important buying factor, try the actual controls rather than assuming the more expensive mechanism will suit everyone.
Do not buy the 365 for extra capacity
The published waste and flush capacities are the same. The level indicator is a convenience for monitoring the 365; it does not create a longer guaranteed interval between emptying.
For either model, plan emptying around use, the instructions and a manageable carrying weight. You can service the tank before it is full. Confirm the campsite’s authorised disposal point and accepted products before travelling.
Check the complete space
Allow room to open the lid, sit, stand and operate the blade, plus space to remove the waste tank. Identical closed dimensions do not mean either toilet will work in an enclosure that barely fits the base.
Consider compatible spare parts, cleaning supplies and any storage bag separately. Check the included accessories rather than assuming a listing photograph shows everything in the package.
Which should you buy?
Compare the Porta Potti 165 on Amazon UK and Porta Potti 365 on Amazon UK. Select the exact model before comparing current prices.
Pick the 165 if you are comfortable with its bellows pump and monitoring routine. Pick the 365 if the piston action and indicator improve daily use enough to warrant the difference. The more useful choice is the one the campers can operate and empty comfortably.
Continue with our camping wash guide.
Reviewed 10 September 2026. This guide is based on published specifications and guidance.