Black tank flush back flow location

[cdougmark]

Anyone familiar with the location of the black tank flush back flow valve on a 2015 28SGS 5th wheel?

It is not under the bathroom or kitchen sinks. I don't see another water line from the pass through going up into the bathroom except for sink, toilet and shower. Don't want to pull down under belly to trace the line if it can be avoided.

It sprays only for a few seconds and then there is a thump and it builds up pressure. We are done with it for the year however am concerned about freezing since it did not spray and may have residual water.

From my research on here and from what the local tech told me the back flow is likely the problem. Dealer will address under warranty but first opening is not until Jan.

Thanks

[JRTJH]

The 28SGS and the 27RKS have identical "top floor plans". That said, your black tank flush coupling is above the water heater on the road side. The 1/2" PEX tubing is routed from the sidewall directly to the hole in the vanity cabinet and up under the sink, then back down to the rear side of the black tank. If you open your vanity, look inside where the red and blue PEX lines (hot and cold water) are located, you'll also see two white PEX lines. They are the black tank flush lines. The anti-siphon valve is located up at the very top of the vanity, behind the sink and nestled alongside the faucet connections.

It's easy to miss, but get a good, bright light, move everything off the top shelf and you'll see it once you've got your head inside the cabinet with your forehead touching the drain.

Good Luck

[hankaye]

JRTH, Howdy;

Originally Posted by JRTJH

The 28SGS and the 27RKS have identical "top floor plans". That said, your black tank flush coupling is above the water heater on the road side. The 1/2" PEX tubing is routed from the sidewall directly to the hole in the vanity cabinet and up under the sink, then back down to the rear side of the black tank. If you open your vanity, look inside where the red and blue PEX lines (hot and cold water) are located, you'll also see two white PEX lines. They are the black tank flush lines. The anti-siphon valve is located up at the very top of the vanity, behind the sink and nestled alongside the faucet connections.

It's easy to miss, but get a good, bright light, move everything off the top shelf and you'll see it once you've got your head inside the cabinet with your forehead touching the drain.

Good Luck

You forgot to welcome "cdougmark" to the Keystone version of Circ de RV.

hankaye

[cdougmark]

Thanks for the response. Was able to locate 2 white water lines going up through floor above the water heater in same hole as the shower water lines. Assume back flow is in the shower wall, it is definitely not under the vanity. Due to major back surgery haven't had time to do any further investigation. Dealer says not to worry about freezing as any water should have drained. Dealer will repair any damage and test in Jan 2015 prior to warranty expiration.

[Bowti]

Originally Posted by JRTJH

The 28SGS and the 27RKS have identical "top floor plans". That said, your black tank flush coupling is above the water heater on the road side. The 1/2" PEX tubing is routed from the sidewall directly to the hole in the vanity cabinet and up under the sink, then back down to the rear side of the black tank. If you open your vanity, look inside where the red and blue PEX lines (hot and cold water) are located, you'll also see two white PEX lines. They are the black tank flush lines. The anti-siphon valve is located up at the very top of the vanity, behind the sink and nestled alongside the faucet connections.

It's easy to miss, but get a good, bright light, move everything off the top shelf and you'll see it once you've got your head inside the cabinet with your forehead touching the drain.

Good Luck

Good to know information. Thanks John