Inspecting swimming pool filters during a home inspection is a visual and operational check for safety, obvious defects, and basic performance, not a maintenance service or code certification.

Scope and limitations

  • Inspect only readily visible and accessible components; do not disassemble tanks, remove internal grids, or perform media changes.
  • Do not exceed the system’s normal operating pressure or bleed valves, loosen clamps, or open tanks; filter tanks can explode if clamps or fasteners fail under pressure.
  • Do not certify design flow rates, filter sizing, or full compliance with any specific code or manufacturer specification; recommend a qualified pool professional where needed.

Identification and documentation

  • Identify filter type (sand, cartridge, D.E.) and record make/model or estimated size if legible.
  • Note the approximate filter location, accessibility, and working clearances around the tank and valves.
  • Confirm presence and legibility of equipment labels, safety warnings, and flow/valve labels where provided.

Filter tank, clamps, and safety features

  • Inspect the tank body for cracks, bulges, corrosion, UV damage, or previous repair attempts; note any leakage or patching at seams, drain plugs, or fittings.
  • Evaluate the clamp/band or fastening system: look for rust, deformation, missing hardware, or evidence it does not fully seat in the tank grooves; degraded or damaged clamps are a critical safety defect.
  • Confirm an air pressure‑relief valve is present on pressure filter tanks and appears intact and operable (handle/knob moves, not obviously broken).
  • Check that the tank is properly supported on a stable, level pad and not shifting, tilting, or bearing on unsupported piping.

Piping, valves, and gauges

  • Inspect visible suction and return piping at the filter for leaks, impact damage, poor support, excessive bends, or obvious deterioration.
  • Verify valves are present and appear functional, with handles intact and positions reasonably labeled or intuitive; mis-labeled or unmarked manifolds can be called out.
  • Confirm influent and effluent pressure gauges (and any vacuum gauges) are present where expected, mounted securely, and show plausible readings under operation; inoperative or missing gauges should be noted.
  • Look for a sight glass or visible discharge point on backwash lines where required, and that backwash discharge is routed to an appropriate location, not eroding soil or discharging against structures.

Operational checks (without servicing)

  • Run the circulation system, observing that the pump primes, water visibly circulates, and the filter tank and connected piping do not leak under normal operating pressure.
  • Note the operating pressure at the gauge and, if a “clean” baseline is provided on site, whether current pressure appears elevated; if substantially above the indicated normal range, recommend cleaning/service.
  • Observe flow at returns and skimmers: markedly weak return flow or poor skimming may indicate a dirty filter, blocked plumbing, undersized equipment, or other conditions meriting further evaluation.
  • Do not initiate backwashing, open air bleeds, cycle multiport valves under load, or power the system on/off repeatedly; recommend service if the owner reports operating issues.

Type‑specific points

  • Sand filters:
    • Inspect multiport or push‑pull backwash valves for leaks at the stem, cover, and unions, and for damaged or missing handles.
    • Call out visible channeling, sand discharge into the pool, or labeled media replacement that appears overdue if documentation is present; otherwise, defer exact media condition to a pool technician.
  • Cartridge filters:
    • Note condition of the tank lid and locking mechanism and any signs of water bypass or leakage at the lid O‑ring.
    • If the owner states cartridges are very old, or pressure is high with poor flow, recommend service and cartridge inspection/replacement without attempting removal yourself.
  • E. filters:
    • Confirm any required backwash or recharge labeling is present and that waste/backwash piping is in place.
    • Recognize that handling D.E. requires proper procedures; do not open the tank or disturb grids or D.E. powder.

Electrical, bonding, and ancillary safety

  • Verify that filter‑pump equipment is on a proper mounting pad with clear access to a disconnecting means you can operate without reaching over water or standing in wet areas.
  • Observe that metallic components of the pump, filter, and associated hardware appear bonded with appropriate conductors where required; missing or loose bonding should be reported as a safety concern.
  • Note any obvious entrapment risks associated with the filter system’s operation, including missing or damaged drain covers or flow rates that appear excessive for visible outlet grates, and recommend evaluation if concerns are noted.

Reporting and recommendations

  • Describe the filter type, apparent condition (satisfactory, marginal, defective, not inspected), and any observed safety concerns such as damaged tanks, compromised clamps, missing relief valves, or leaks under pressure.
  • State clearly that the inspection is visual and non‑invasive and does not include internal inspection, pressure testing, or certification of filter performance or compliance. Recommend evaluation, cleaning, or repair by a qualified pool professional when abnormal pressure, poor flow, leakage, damage, or safety defects are observed.