Alpine 3700FL Black Tank Flush

[haiduan]

When I flush the rear black tank I am getting a small amount of clear water showing up under the bathroom sink. I can't tell where the water is coming from. I get probably about a quart of water when I flush for an hour. No water showing up anywhere else. Storage bays are dry.

This just started in the past year. Doesn't make any sense. Any ideas?

[chuckster57]

Look under the sink up high for the anti siphon valve. Its most likely black and it has failed. You can replace it with the same type or you can go to any big box hardware store and get an upgraded one.

Factory original :https://www.amazon.com/RecPro-Breake...04481564&psc=1

Upgraded:https://www.amazon.com/Cash-Acme-173...pcontext&psc=1