Swimming Pool Troubleshooting:
My Pool is losing water – process of elimination.
Pressure test pipework between the pool and the plant room. To do this you need specialised equipment.
Visually check the pool surface for deformation, cracking or lining issues.
Check around the pool fittings and gaskets, check the skimmers for cracks especially in an outdoor pool after a cold winter.
Check the pools underwater lights, the cable glands and grommets are tight and correctly sealed.
Check the pools automatic cover cable conduit and cable glands are correctly sealed.
Check pools surround deck boxes and cable connection boxes for leaks.
Check the pools balance tank for damage or leakage.
Check the valve/Multiport valve on the waste line, check that water is not passing through the valve whist in a closed position.
All pools have a top up system either pool side via a float valve/fill valve, via a top up which is controlled via a float switch in a skimmer or a float valve or a top up controller controlled by sensors in the pools balance tank. You can paste this straight into Word and use it as a general “Pool Problems & Troubleshooting Guide” for customers.
Common Pool Problems & Troubleshooting Guide
A Simple Guide for Pool Owners
Pools are generally reliable, but like any system they can occasionally develop issues. This guide helps you identify common problems, carry out basic checks, and understand when to call a pool professional.
1. Pool Losing Water
Some water loss is normal due to evaporation. Excessive or continuous loss may indicate a leak.
What to Check
Mark the water level on the pool wall or skimmer and recheck after 24–48 hours.
Inspect the pool surface for cracks, damage, or liner issues.
Check skimmers, return inlets, gaskets, and fittings for cracks or loose seals.
Inspect underwater lights, ensuring cable glands and grommets are sealed.
Check the pools automatic cover conduits, deck boxes, and cable connection boxes for dampness.
Inspect the balance tank (if fitted) for cracks or unexplained level changes.
Check valves and the multiport valve to ensure water is not passing to waste when closed.
Check automatic top‑up systems to ensure they are not stuck open and masking a leak.
When to Call a Professional
Pipework pressure testing between the pool and plant room requires specialised equipment.
If the source of water loss cannot be identified.
2. Cloudy or Milky Water
Cloudy water is one of the most common pool complaints and is usually caused by water balance or filtration issues.
What to Check
Test and adjust water chemistry (chlorine, pH, alkalinity).
Check that the pump and filter are running for the recommended daily hours.
Inspect the filter for blockages or overdue cleaning/backwashing.
Remove debris from skimmer baskets and pump strainer baskets.
Common Causes
Poor circulation
Dirty or overloaded filter
Incorrect chemical balance
High bather load or debris after storms
3. Green Water or Algae Growth
Green water is typically caused by algae due to insufficient sanitation.
What to Check
Test chlorine levels and raise if low.
Brush pool walls and floor to remove algae.
Ensure filtration is running long enough each day.
Clean or backwash the filter after treatment.
Prevention Tips
Maintain consistent chlorine levels
Regular brushing and vacuuming
Adequate circulation and filtration
4. Strong Chlorine Smell or Eye Irritation
A strong chlorine smell does not usually mean too much chlorine—it often means poor water balance.
What to Check
Test pH and chlorine levels.
Shock the pool if combined chloramines are present.
Ensure adequate circulation and fresh water dilution if needed.
5. Low Suction or Poor Circulation
If the pool cleaner is weak or water flow is reduced, circulation may be restricted.
What to Check
Empty skimmer and pump baskets.
Check for blocked suction lines.
Inspect the pump lid seal for air leaks.
Ensure valves are fully open and correctly positioned.
6. Air Bubbles in Pool Returns
Air coming from return jets can indicate air entering the system.
What to Check
Water level is high enough to cover skimmer openings.
Pump lid and O‑ring are clean and sealed.
No visible leaks on the suction side pipework.
7. Pump Not Running or Switching Off
What to Check
Power supply and circuit breakers.
Pump timer settings.
Overheating due to blocked pipework or blocked baskets.
Unusual noises, vibrations, or leaks.
⚠️ Electrical faults should always be checked by a qualified professional.
8. Heater Not Heating the Pool
What to Check
Pool water flow is adequate.
Filters are clean and not restricting circulation.
Heater settings and thermostat are correct.
No visible error indicators or warning lights.
9. Automatic Water Level Problems
If the pool water level is too high or too low:
What to Check
Float valves or sensors are moving freely.
The system is not stuck open or blocked.
The top‑up system is not compensating for an unseen leak.