Common mistakes

Wrong capacity

Too small means constant refill; too large can overload payload and carry stale water. Size from measured use and legal dump/refill reality.

Bad breathing and drainage

No vent, undersized vent, no full drain, no low points, tiny grey tank or sagging drain lines. Tanks then deform, burp, smell or never empty.

Bad pressure path

Oversized pump, no strainer/regulator, restrictive filter stack, mismatched tubing/fittings or relief valve mistakes. Every component must share a safe pressure/flow envelope.

No service/freeze plan

Hidden joints, inaccessible filter bowls, no isolation, exterior lines without drain-back and assuming insulation prevents freezing. Build for the repair you will eventually make.

Build rule

If you cannot reach it, isolate it, drain it and explain its pressure/temperature or water-quality job, it is not ready to hide behind a wall.

CHAPTER CHECK

• I can explain the purpose and failure mode of each item in this chapter. • I know which manufacturer limit or water-quality claim controls my choice. • I added the valve, access, drain, measurement or maintenance task to my drawing/checklist.