The pressure gauge on the machine says one thing. The jet at the far end of the yard tells a different story.
Nothing has failed. The pump generates the pressure, and the hose spends some of it before the water reaches the gun.
How much it spends depends on length, bore, couplings and how you treat the hose. You control every one of those variables.
Why a hose loses pressure at all
Water rubs against the inside wall of the hose as it moves. That friction converts some of your pressure into heat and turbulence.
The trade calls it friction loss, and it exists on every machine and every hose assembly.
Length is the first factor. Double the hose and you approximately double the friction the water has to overcome.
Flow is the second. Push more litres per minute through the same hose and the loss increases faster than the flow does.
So a high flow commercial pump on a long run suffers more than a compact machine on a short hose.
That is why the gauge on the machine reads higher than the pressure arriving at the nozzle.
Bore matters more than most people think
Bore is the internal diameter of the hose. A narrow bore forces the same flow through a smaller channel.
The water travels faster, creates more turbulence and loses more pressure along the way. A small step up in bore can cut the loss by a useful margin.
You will find the bore printed on the outer cover, beside the pressure and temperature rating.
We will not quote a bar per metre figure, because it varies with flow, temperature and hose construction. The principle applies to every setup, though.
Match the bore to the job. A domestic machine on a short hose seldom needs a wide bore. A commercial pump on a long run often does.
If you are unsure what bore your machine needs, our Kränzle hoses list the sizes. You can also send us the model number and ask.
Extension hoses add more than length
Connecting two hoses together feels like a free solution. It is not.
Every coupling restricts the flow path for a moment, and that adds its own small loss. Three hoses joined together means more couplings and more loss on top of the extra length.
Each joint is also a leak point. A worn O-ring at a coupling weeps under pressure. On a Total Stop machine, that weep can make the motor cycle on and off.
If the machine already struggles to hold pressure, read our pressure diagnosis guide before you add another length.
One long hose of the right bore beats several short ones joined together. It has fewer seals to wear and fewer places to snag.
Couplings also add weight and bulk, which makes the hose catch on kerbs, doorsteps and vehicle wheels.
Hose reels need their own rules
A hose reel keeps the hose organised and off the ground, which protects the outer cover. It also introduces two habits worth learning.
Unwind it fully when you run hot water. A coiled hose traps heat, because each layer sits against the next one.
On a hot water machine, that heat builds up inside the coil. The rubber softens, the hose ages faster and the rating can suffer. Heat also expands the hose against the drum, which stresses the fittings at each end.
Watch the swivel joint. Every reel has a rotating seal where the water enters the drum. Dragging the reel and yanking the hose accelerate wear on that seal.
A weeping swivel loses pressure and drips continuously onto the frame. Our guide to lances, nozzles and reels covers the options if yours needs replacing.
Pressure and temperature rating
Every high pressure hose carries a rating for maximum pressure and maximum temperature. Both specifications matter.
A hose rated for cold water can fail on a hot water machine. The temperature degrades the inner layer, and the hose eventually ruptures under pressure.
Hot water needs a hose rated for hot water. If you run one of our hot water pressure washers, check the hose rating before you fit anything new.
Compare the printed rating on the hose cover with the maximum pressure on the machine's data plate.
Never fit a hose rated below the machine's maximum pressure. A burst at full pressure can cause a serious injection injury.
Our guide to pressure washer safety explains why those injuries need a hospital, not a plaster.
Routing the hose properly
Careless routing costs pressure and destroys hoses prematurely.
Kinks restrict the flow. A tight bend behaves like a narrow bore at one point, and it stresses the steel braid inside.
Never drive over it. A vehicle wheel crushes the braid even when the rubber looks fine afterwards. The hose can then fail weeks later at that spot.
Keep it off sharp edges. Kerbs, steel frames and brick corners gradually abrade the outer cover. Once the braid shows, replace the entire hose assembly.
Position the hose in long, loose curves and keep it out of doorways where it gets trapped.
Experienced operators run the hose along the edge of a building, away from foot traffic and reversing vehicles.
Longer hose or move the machine?
Here is the practical test. If repositioning the machine takes a few minutes, move it.
A shorter hose delivers more pressure at the gun and less weight in your hand. It also puts less strain on the pump. Every extra metre adds weight you drag around the site, which tires your arms over a long shift.
A longer hose makes sense when the machine cannot move. Think of a fixed wall mounted installation, a cramped yard or an electrical supply in one location.
Watch for knock-on effects. A long, narrow hose can starve flow at the attachment. A surface cleaner then rotates sluggishly or stalls.
Our guide to surface cleaner stalling explains how flow and setup interact. Nozzle choice plays a part too, and our nozzle size guide covers that.
Signs a hose needs replacing
Hoses deteriorate, and they seldom give much warning. Inspect yours before every big job.
Look for these signs:
Bulges or soft spots anywhere along the hose.
Cracks in the outer cover, or braid showing through.
Weeping or corrosion where the metal crimp meets the rubber.
A hose that stays rigid and kinks repeatedly in the same position.
Any of these indicates replacement. Do not tape it, and do not wait for it to burst.
A new hose costs far less than a burst hose, a damaged vehicle panel or an injury claim.
Storage decides how long a hose lasts. Drain it after use, coil it in loose loops and hang it on a wide bracket.
A narrow hook creates a permanent kink at the same point every time. Sunlight and frost both degrade the rubber faster than dry indoor storage.
Frequently asked questions
How much pressure does a long pressure washer hose lose?
It depends on the flow, the bore and the hose build, so there is no single figure. Loss rises with length and climbs faster at higher flow.
Does a wider bore hose give more pressure?
It loses less pressure along the way, so more reaches the gun. The pump still makes the same pressure at the outlet.
Can I join two Kranzle hoses together?
Yes, with the correct coupling. Each joint adds a little loss and another seal that can leak, so one longer hose is usually better.
Why does my hose reel get hot?
A coiled hose traps heat from a hot water machine. Unwind the reel fully whenever you run hot water.
Can I use a cold water hose on a hot water machine?
No. Fit a hose rated for both the pressure and the temperature of your machine.
How often should I replace a pressure washer hose?
There is no fixed interval, because use and storage vary from one operator to the next. Inspect the hose before each big job and replace it at the first sign of damage.
The bottom line
Every metre of hose costs pressure, and every joint costs a little more. A narrow bore makes it worse.
Keep the run as short as the job allows. Use one hose with the correct bore and the correct rating, and maintain it properly.
Not sure what your setup needs? Send us the model number and the length you need to reach. We will recommend the right hose before you buy.
If the pressure is still poor with a short hose, the fault may sit in the pump. Book a full workshop service at our Bedfordshire workshop, with a written report and twelve months warranty on our workmanship.