Pressure Washer Problems Explained: Low Pressure, Leaks & Noise
Keter Manor Outdoor Apex Double Door Garden Storage Shed (6 x 8ft)
A durable and stylish beige and brown garden storage shed perfect for storing garden tools, equipment, bikes, and outdoor essentials. Weather-resistant, low maintenance, and ideal for any garden or allotment setup.
🌱 Compost & Soil Improvers
Give your garden beds a boost before winter with compost and organic matter.
Shop Compost & Soil Improvers
🌿 Autumn Plant Feed & Fertiliser
Prepare your soil for autumn planting with suitable fertilisers and soil nutrients.
Browse Garden Fertilisers
🥬 Seed Trays & Propagation Kits
Keep growing through autumn by starting suitable hardy crops under cover.
Shop Seed Trays
Pressure washers are tough machines, but even good models can develop problems over time. Most issues — low pressure, water leaks and unusual noise — are caused by simple faults rather than serious failures.
This guide explains the most common pressure washer problems, why they happen, and what you can realistically fix yourself.
⭐ Recommended Products — Pressure Washers & Outdoor Cleaning Tools
• Electric Pressure Washer (Corded)
A reliable, easy-to-use mains-powered washer — perfect for cleaning patios, garden furniture, driveways, and decking with consistent pressure.
👉 Click here to see top options
• Cordless (Battery) Pressure Washer
Portable and convenient with no trailing cable — ideal for patios, cars, garden walls, and bikes. Great if you want flexible cleaning around the garden.
👉 Click here to see top options
• Petrol Pressure Washer
Higher power and flow for tougher cleaning jobs — excellent for large driveways, brickwork, and heavily soiled surfaces where extra grunt helps.
👉 Click here to see top options
• Pressure Washer Accessory Kit
Includes a range of nozzles, extension wands, brushes, and surface cleaners — expands the versatility of your washer for different surfaces and jobs.
👉 Click here to see top options
• Pressure Washer Detergent & Cleaning Solutions
Specialised soaps and detergents formulated for use with pressure washers — boosts performance on grease, algae, and stubborn grime on outdoor surfaces.
👉 Click here to see top options
🚿 Problem 1: Low Pressure or Weak Spray
Low pressure is the most common complaint and usually the easiest to fix.
Common Causes
✔ Blocked nozzle — dirt or grit restricts water flow
✔ Air in the system — especially after storage
✔ Low water supply — tap not fully open or restricted hose
✔ Worn nozzle — spray tip enlarged over time
✔ Incorrect nozzle fitted — wide fan instead of narrow jet
What to Do
• Remove and clean the nozzle with a pin or nozzle tool
• Run water through the machine without the lance attached to remove air
• Check hose for kinks or restrictions
• Try a different nozzle or spray setting
• Ensure your outdoor tap provides adequate flow
Tip: Low pressure is rarely a motor fault — check accessories first.
💧 Problem 2: Water Leaking From the Machine or Hose
Leaks look worrying but are often caused by seals or fittings.
Common Causes
✔ Loose hose or lance connections
✔ Worn or damaged O-rings
✔ Split or kinked hose
✔ Cracked plastic connectors
✔ Internal seal wear (less common)
What to Do
• Tighten all connections firmly (hand-tight, not forced)
• Inspect O-rings and replace if flattened or cracked
• Straighten hose fully during use
• Replace damaged connectors — cheap parts cause most leaks
When to worry:
If water leaks from the pump housing itself, internal seals may be failing — this may need professional repair.
🔊 Problem 3: Loud Noise, Knocking or Vibrating
Pressure washers are noisy — but new or harsh sounds usually indicate a problem.
Common Causes
✔ Air trapped in the pump
✔ Cavitation from poor water supply
✔ Loose internal components
✔ Pump running dry
✔ Worn bearings or pump parts
What to Do
• Bleed air by running water through with the trigger held down
• Check tap flow rate and hose diameter
• Never run the washer without water
• Inspect for loose external screws or panels
Warning:
Grinding or metallic knocking usually means internal wear — stop using the washer to avoid further damage.
⚡ Problem 4: Washer Pulsing On and Off
This often feels like pressure surging while cleaning.
Common Causes
✔ Trigger not fully open
✔ Blocked nozzle
✔ Air leaks in hose or fittings
✔ Faulty unloader valve
What to Do
• Hold the trigger fully open during use
• Clean or replace the nozzle
• Check hose connections for air ingress
• Replace worn seals if pulsing continues
🧯 Problem 5: Washer Stops or Cuts Out
Common Causes
✔ Overheating motor
✔ Thermal cut-out activation
✔ Electrical extension lead issues
✔ Low voltage supply
What to Do
• Let the washer cool down fully
• Use a short, heavy-duty extension lead
• Avoid running continuously for long periods
• Check plug and socket condition
Preventing Pressure Washer Problems
✔ Flush water through before and after use
✔ Clean nozzles regularly
✔ Store hoses straight, not coiled tightly
✔ Drain water before winter storage
✔ Never run the machine dry
Good maintenance prevents most pressure washer faults.
When to Repair vs Replace
Repair is worth it if:
✔ Issue is nozzle, hose or seals
✔ Machine is under 5–7 years old
✔ Brand spares are easily available
Replace if:
✔ Pump housing is leaking
✔ Motor is failing
✔ Repair cost approaches replacement price
Final Thoughts
Most pressure washer problems — low pressure, leaks and noise — are caused by blockages, air in the system or worn accessories, not major failures. Start with simple checks before assuming the worst.
A well-maintained pressure washer should deliver strong pressure, stable performance and reasonable noise levels for many years. Fix the small issues early, and your machine will keep working when you need it most.