Hot tubs, spas and pool equipment combine three washer killers: heat, constant water, and pool chemicals like chlorine and bromine. The right rubber washer holds up; the wrong one fails fast.
The challenge
- Sustained warm-to-hot water
- Continuous moisture and immersion
- Oxidizing chemicals (chlorine, bromine, ozone)
Best materials
EPDM is the standout for spa and pool use — it handles hot water, ozone and weather extremely well. Silicone is excellent where heat is highest and offers great chemical stability; see the silicone guide. For strong chemical exposure, Viton is the premium option. Avoid natural rubber and nitrile for sustained hot, chlorinated water.
Common uses
Pump unions, heater fittings, jet assemblies, filter housings and plumbing connections all rely on a chemical- and heat-resistant washer to stay leak-free.
Compare compounds in the material guide, size it in the size guide, and shop by size here.