A leaking hose at a freedom camping spot, a blocked toilet before a long weekend, or a fresh-water tank that suddenly smells odd can spoil an otherwise good trip. RV plumbing is not complicated, but it does need regular attention. A few simple checks before leaving home will save water, protect your van, and make waste disposal far less stressful.
For most NZ travellers, the key is understanding that an RV has separate systems for fresh water, grey water and toilet waste. They should stay separate from the moment water enters the van until it is emptied at an approved dump station.
How RV plumbing works
An RV water system starts with the fresh-water tank. This tank supplies water to the kitchen sink, shower, basin and sometimes the toilet. A 12-volt pressure pump draws water from the tank and sends it through pipes to each tap. When you open a tap, pressure drops and the pump starts. When you close it, the pump should stop once pressure builds again.
Water used in the sink and shower becomes grey water. It drains into a separate grey-water tank and must be emptied at an approved facility. Even if it looks harmless, grey water can contain food scraps, grease, soap, hair and chemicals. It does not belong in a stormwater drain, on the ground, or near waterways.
Toilet waste is held separately again, either in a cassette toilet, portable holding tank or a fixed black-water system. The layout varies between vans, but the rule remains the same: use the right chemicals, keep seals clean, and empty only at a suitable dump station.
The fresh-water side
Fresh water deserves the most care because it is what you cook, wash and possibly drink with. Fill only from known potable-water taps and use a hose reserved for drinking water. A general-purpose hose that has sat in the boot beside fuel containers, tools or dirty fittings is not a good choice.
Keep the hose ends capped when stored. Before connecting, let the supply tap run briefly to clear stale water from the outlet. If the tap fitting is muddy or questionable, find another source. It is a small decision that can prevent an unpleasant stomach bug when you are well away from home.
If your fresh-water tank is not used regularly, flush and sanitise it according to the tank or vehicle manufacturer’s instructions. A clean tank, clean hose and working filter give you a much better start than trying to fix poor-tasting water halfway through a trip.
The waste-water side
Grey-water plumbing is usually simple: sink and shower drains feed a tank, then a larger outlet hose and valve are used for emptying. The common problems are food scraps, hair, grease and a valve left partly open or not cleaned after use.
Use a sink strainer and wipe oily pans with paper before washing them. This reduces build-up in the pipes and tank. After emptying, rinse the hose and close the valve properly before putting it away. Check that the cap is secure as well. A loose cap can turn a rough road into a messy job at the next stop.
For toilet waste, avoid overfilling. Most problems happen when people wait until the tank is completely full, then discover a queue at the dump station or a difficult access point. Empty early when convenient, particularly before heading into remote areas or busy holiday destinations.
The RV plumbing checks worth doing before every trip
You do not need to pull the whole system apart before each outing. A quick practical inspection is usually enough. Fill the fresh-water tank partway, turn on the pump and open each tap one at a time. Check under the sink, around the shower fittings, and near the water pump for drips.
Then turn all taps off and listen. The pump should stop. If it keeps cycling when no water is being used, there may be a leak, a loose fitting, a faulty non-return valve or an issue with the pump pressure switch. Do not ignore it. A slow leak can empty a tank, flatten a battery through repeated pump cycling, and damage cabinetry or flooring.
Check your waste valves, caps and hoses as well. Rubber seals dry out over time, especially after a van has been parked through summer. Clean the seals, use a suitable lubricant where recommended, and replace cracked hose fittings before they fail on the road.
A sensible pre-trip kit includes a dedicated drinking-water hose, waste hose, spare hose washers, a couple of caps, gloves, cleaning wipes and a small torch. These are basic items, but they are the ones that turn a minor issue into a five-minute fix instead of a detour to town.
Water pressure: more is not always better
Caravan parks and campgrounds can have very different water pressure. Connecting directly to a mains tap without a pressure regulator can put strain on older fittings, hoses and internal plumbing. A regulator helps protect the system from a sudden pressure spike and gives you more consistent flow.
If you use a direct mains connection, check the fittings after the first few minutes and again before bed. A leak that starts slowly can go unnoticed overnight. When you leave the van unattended, it is generally wise to turn off the external water supply rather than relying on hoses and fittings to behave perfectly.
Low flow is a different issue. It may be caused by a blocked tap aerator, clogged filter, a kinked hose, a low tank level or a tired pressure pump. Start with the easy checks before assuming the pump needs replacing. Many flow issues come down to sediment in a filter or debris in an aerator.
Choosing the right pump arrangement
Where wastewater needs to be pumped rather than drained by gravity, choose equipment suited to the job and the pipe size. For domestic-style wastewater arrangements, vortex and centrifugal pumps are generally the more reliable option. They are designed to move water and suitable solids with fewer of the reliability issues associated with older domestic macerator arrangements.
Portable and specialised waste systems have their own requirements. Storeit4less uses the BLACKBOX-270SUPERMAX macerator/cutter pump in its purpose-built portable waste management setup, where controlled transfer of waste is required. The important point is not to force one pump style into every installation. The tank size, pipe run, lift, outlet access and expected use all matter.
If your van has a pump that is noisy, runs continuously, trips a fuse or struggles to clear a line, get the cause checked before your next trip. Electrical faults and blockages rarely improve by being used harder.
Keeping smells and blockages under control
Bad smells are often blamed on the toilet tank, but the source can also be a dry drain trap, a blocked roof vent, stale grey water or residue in the hose. Start with the simple causes. Run water through every drain, empty the grey-water tank, rinse the waste hose, and check that vents are clear.
Use products that are suitable for RV holding tanks and follow the dosage instructions. More chemical is not always better. The aim is to control odour and help keep the tank clean, not create a harsh mix that affects seals or makes disposal difficult.
Do not put wipes, paper towels, sanitary products, cooking fat or food scraps down the toilet or sink. Even products labelled as flushable can cause trouble in small tanks and narrow pipework. RV systems are compact by design, so they have less room to forgive poor habits.
Dump stations are part of the journey plan
A well-run RV trip includes a waste plan, not just a route and a place to sleep. Know where approved dump stations are before you need one. Holiday periods can make popular facilities busy, and some sites have access limitations for larger motorhomes or vehicles towing trailers.
At the dump station, take your time and leave it clean for the next person. Wear gloves, keep hose connections controlled, rinse down the area if needed, and secure everything before driving away. Good waste habits help keep facilities available and protect the places we all travel to enjoy.
Treat your plumbing system like the practical piece of equipment it is. Keep it clean, inspect it often, fix small faults early, and plan disposal before the tanks are full. That leaves more time for the beach, the bach, the bush track or simply a quiet night parked somewhere worth waking up in.