I’ve had been doing business with SpectraPure since 2001. I’ve had many calls and maintenance with my system that has been been providing purified RO water for many years. The shut off valve may be at the end of it's life, although it was changed in 2007. Great value but know if your 3-stage RO under the sink water filter is making a loud humming sound, this little part could be the culprit!