Why does my water pump cycle when no tap is open?

Because there is a leak somewhere in the pressurised side, or the pump check valve is passing. Cycling with everything closed means pressure is dropping, and pressure only drops if water is going somewhere. This is worth chasing immediately rather than tolerating, because a slow leak inside a wall or under a floor is exactly the failure that produces a large water damage bill.

How do I stop tank odours?

Usually not with more chemicals. Odour is normally caused by insufficient water in the black tank, so solids are not breaking down, or by a blocked roof vent, or by a dried out toilet seal letting gas back into the coach. Use plenty of water on every flush, keep the tank valve closed until it is at least two thirds full so it flushes properly, and check the vent is clear. Chemicals mask a symptom that has a mechanical cause.

Can a cracked fresh water or waste tank be repaired?

Sometimes. Polyethylene tanks can be welded plastically by someone who knows what they are doing, and a repair at a seam or a fitting boss frequently holds well. Cracks that run through a mounting point or across a large span usually justify replacement, because the tank is flexing and the repair will crack alongside the old one. Access is often the larger cost either way, since tanks are frequently boxed in behind structure.

How much does RV plumbing repair cost?

A leak repair or fixture replacement is $400 to $1,200. Pump or water heater work is $600 to $2,500. Tank repair or replacement is $1,500 to $6,000 depending heavily on access. A full system replacement on a rebuild runs $4,500 to $9,500.

What is involved in winterising?

Draining the fresh system, bypassing and draining the water heater, blowing lines clear with low pressure air, and either leaving the system dry or introducing RV antifreeze through the pump. In Southern California most owners never need it, but anyone travelling to altitude or out of state in winter does, and a single freeze event that splits a line inside a wall is far more expensive than the service.

RV Plumbing Repair, Tanks and Water Systems

Plumbing failures in a recreational vehicle are disproportionately damaging compared to the same failure in a house, and the reason is architectural.

In a house, a leaking fitting drips onto a floor you can see, in a room with a drain nearby, over a structure designed to get wet occasionally. In a coach, the same fitting is inside a sealed cavity, above a wooden floor, with no drain and no visibility. The water goes into the structure and stays there, and the first symptom is frequently a soft floor months later.

So the useful posture on RV plumbing is that small leaks are urgent.

The systems

Fresh water. Tank, pump, accumulator, distribution, and a city water inlet with a regulator. The regulator matters: park water pressure varies wildly and an unregulated supply will burst a fitting.

Water heater. Suburban, Atwood, Truma or a hydronic system such as AquaHot on larger coaches. Gas, electric or both.

Waste. Grey tank from sinks and shower, black tank from the toilet, valves, and a vent stack to the roof.

Fixtures. Toilet, sinks, shower, exterior shower, and on larger coaches a washer connection.

What fails and why

Fittings and connections. Vibration works every joint continuously. Push-fit connectors that were installed slightly out of square, crimp rings that were under-crimped, and threaded joints that were over-tightened all fail eventually.

Pumps. Diaphragm wear, pressure switch failure, and check valves that pass. A pump cycling with all taps closed is reporting a leak or a failed check valve, and either way something is losing pressure.

Water heaters. Element failure on electric, burner and thermocouple issues on gas, tank corrosion, and anode rods that were never replaced.

Tanks. Cracks at mounting points and fitting bosses, usually from flex or from freezing.

Valves. Blade valves on waste tanks seize, and the seal behind the blade fails, which is what produces a valve that closes but weeps.

Vents. A blocked or capped roof vent stops the tank breathing, which causes both slow draining and odour.

Freeze damage. Split lines and fittings from a single unprotected freeze, usually discovered in spring.

What we do

Leak diagnosis and repair, line replacement and rerouting, pump replacement and pressure regulation, water heater service and replacement including hydronic systems, fresh and waste tank repair and replacement, valve and seal replacement, toilet, sink and shower repair and replacement, macerator and sewer pump work, full system replacement on rebuilds and conversions, winterising and de-winterising, and sanitising.

What it costs

Job	Typical range	Hours
Leak diagnosis and repair	$400 to $1,200	2 to 6
Water pump replacement	$500 to $1,200	2 to 5
Water heater service	$400 to $1,000	2 to 5
Water heater replacement	$1,200 to $3,500	5 to 14
Toilet replacement	$500 to $1,500	2 to 6
Waste valve and seal replacement	$500 to $1,600	2 to 7
Tank repair or replacement	$1,500 to $6,000	6 to 26
Full system replacement	$4,500 to $9,500	20 to 40
Winterising	$250 to $600	1 to 3

Plumbing labor is $260 per hour where it involves gas or electrical connections, $210 for straightforward line and fixture work. See the pricing page.

Tank work is dominated by access rather than by the tank. A tank that is boxed in behind cabinetry and structure can cost several times what the same repair costs on an accessible unit.

Odour, properly explained

Tank odour has three usual causes and none of them is solved by chemicals.

Insufficient water. Solids need water to break down and to flush. Owners trying to conserve tank capacity by flushing minimally create the problem they then try to treat.

Draining too early. Leaving the black valve open on a full hookup lets liquid run out and leaves solids behind to dry into a pile. Keep it closed until the tank is at least two thirds full, then dump so the volume flushes the tank.

A blocked vent or a dry toilet seal. Gas that cannot leave through the roof comes back through the toilet, and a toilet seal that has dried and shrunk lets it.

Fix the mechanical cause and the chemicals become unnecessary.

When plumbing becomes structural

If a leak has been running for any length of time, the plumbing repair is the small part. What matters is what the water has done to the subfloor and framing, which is water damage restoration territory and is worth assessing at the same time rather than discovering later.

Estimates are $150 and credited back against an authorized repair.

Bring us the job the other shop turned down

We work on all years, all makes and all classes, from Class A diesel pushers down to enclosed cargo trailers. Estimates are $150 and are credited back against an authorized repair, so the money goes toward the work rather than to a shop that never touches your vehicle.

23281 La Palma Ave, Yorba Linda, CA 92887 | (949) 799-3387

Plumbing and Water System Repair