Black tank flush not working

[Ramd3z]

We’ve owned this second hand 2019 imagine 2800bh for a year. I’ve been troubleshooting the black tank flush since we brought it home.

Basically we have no water going into the black tank
and cannot hear water. I’ve replaced the plastic vacuum breaker but I can send water thru the original and new one without issue. For testing I’ve bypassed the breaker and still no luck.

it sounds like I could have a kink or clogged nozzle

if clogged nozzle- how much water would I need to put in the black tank to cover the nozzle for soaking?

if a kink- any tips at how to identify the location?

2019 Imagine 2800

[howson]

if clogged nozzle- how much water would I need to put in the black tank to cover the nozzle for soaking? if a kink- any tips at how to identify the location?

What I'd try is flushing the lines from where the two hoses connect to the vacuum breaker. Temporarily put a splice in with a hose clamp and then see if backflushing to the black hose connection results in water exiting the connection point. Water=line is good.

Then do the same from the other hose that goes down to the black tank.

If the hose down to the black tank doesn't work perhaps, as you suggest, the spray nozzle is clogged.

What I'd try to do is add straight hot water to the black tank. Since I have a 6 gallon water heater, I'd add 6 gallons. With the vacuum breaker reconnected, apply water pressure every couple of minutes (DO NOT LEAVE UNATTENDED WITH WATER PRESSURE APPLIED). Let it drain between applications of water pressure to the black tank flush. After about 30 minutes, drain the black tank and repeat the whole process.

I'd caution against using air pressure in the lines 'cause if the black tank nozzle inadvertently separates from the black tank the only remedy might be a tank replacement--not a fun job. At minimum sealing the hole created by the not missing black tank flush nozzle would be required.

Consider giving Kleen Tank a call, too, for advice. I don't see your specific issue on their website, but if anyone will know how to clear a clogged nozzle it's them. https://kleentank.com/q-and-a/

If it's a kink in a line (and not a clog) the troubleshooting required is dropping the coroplast (the "underbelly") and tracing the black lines. Not fun, but not impossible.

Below is a pic showing the hose and how low the valve is located on my 315RLTS' tank. Your Imagine's should be similar.



Please follow up with what you find and the fix.

Howard

[Ramd3z]

Thanks, Howard! I’ll keep ya posted. I should also add that when I purchased the RV, winterized… the black tank was full. I recently freed up the black tank sensors with 3 minutes using the camco wand cleaner (was surprised). So with seeing how low the nozzle is, I’m putting some hope in the possibility of it being clogged from the previous owner.

that flush port looks to be below the gate and relatively low. My curiosity has been how much liquid would I need to add to cover the flush nozzle… it looks like it may not take too much water to do so.

[Country Campers]

I would use 1/2 tank of water to be sure. Most of the tank sprayers I have seen are towards the middle of the tank but still located near the exit. Assuming you have a typical estimated 36 gallon tank I would use a meter and fill with 20 gallons to start.

Brian