Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
Jayco RV Owners Forum

Thread Tools Search this Thread Display Modes
Old 05-13-2019, 04:44 PM   #1
Junior Member
Join Date: Jul 2018
Location: Cumming
Posts: 23
Gray tank question

I have had my Grayhawk for about nine months and have used seven or eight times. This time out gray water tank shows 1/3 full even though itís empty. Iíve sent post regarding black water tank sensors but not gray. Any thoughts on how I can fix it?
Thanks for any ideas.
Woundtight is offline   Reply With Quote
Old 05-13-2019, 06:11 PM   #2
Senior Member
Join Date: Feb 2017
Location: Kennewick
Posts: 331
The sensors in all of the tanks are horribly imprecise. My gray water does this on occassion and then later in the day it will register empty. The issue is something greasey or slimey is sticking to the small probe (piece of food or something else).

At this time I am not aware of a good solution. Black water readings are usually worse due to TP floating around and sticking to the probe, but it is not unheard of on gray water.

Personally, I just ignore both of these tanks until they hit the 2/3 mark, then don't drain until I "guestimate" they are approaching full if possible. Allowing the tanks to drain when on the full side more thoroughly flushes the crud out.

One trick I have not tried yet, but saw on another forum is dump a couple of large bags of ice into the black tank, top it off and drive it around. The ice acts like a scrubber and loosens stuff up. Not sure how that would work with gray water though.
2016 Jayco GreyHawk 31DS
2016 Jeep Cherokee Trailhawk Toad.
SE Washington State
jd99336 is offline   Reply With Quote
Old 05-13-2019, 06:29 PM   #3
Senior Member
Join Date: Jun 2017
Location: Hilton Head Island
Posts: 295
As has been stated, the sensors for the tanks are very poor and often inaccurate. If I denote a problem with the grey tank, I'll empty both tanks prior to leaving a campground. Then I'll partially fill the grey tank with clean water and add some dish detergent and/or pine oil and a little of the powder I add to the black tank. Then as we are driving to our next destination, the water and soap are sloshing around in the tank, hopefully cleaning off whatever goop was causing the sensors to misread the level. Often, if we are enroute to a destination some distance away, and are doing several one night stays, I won't dump the tanks at each stop, which keeps the solids agitated and everything drains better. Plus I'm a firm believer in flushing the black tank with the black tank flush three or four times when I'm emptying the tank.
Susan, Ed & Ellee (RIP) Katz
2018 Jayco 29MV
2018 Chevy Equinox

Love To Travel 2 is offline   Reply With Quote
Old 05-13-2019, 07:14 PM   #4
Join Date: May 2019
Location: Harrisonburg
Posts: 39
I had the same issues with my 2007 TT. The black was solved with a flex spin wand through the toilet and teaching the kids it's ok to use water in the camper. For whatever reason, they like t ok run water at home but not in the camper???

Grey was tougher. Limiting the size of food particles down the drain imo is a big help. After draining the grey, I refilled with hot water and dawn dish detergent before leaving for the week. Came back following weekend, drained the grey and sensors have been working fine for over a season.

Keep in mind that we leave our camper sit during the season in the same spot.
Yotahilux is offline   Reply With Quote
Old 05-13-2019, 08:07 PM   #5
Senior Member
JimD's Avatar
Join Date: Apr 2017
Location: Inland Empire, California
Posts: 2,005
I read where dishwasher soap is good to use. I would think regular dish soap would suds up quite a bit. Suds sometimes leaves residue on things.

Just thinking outside the sink.
JimD is offline   Reply With Quote
Old 05-13-2019, 11:44 PM   #6
Senior Member
Big1's Avatar
Join Date: Nov 2015
Location: Lakewood, WA.
Posts: 4,540
I make sure that we dump some warm water and some dawn dish soap down in my gray water tank.
2023 Jayco North Point 310RLTS
2022 GMC Denali Ultimate DRW
Retired Army MSG
Big1 is offline   Reply With Quote
Old 05-14-2019, 05:29 AM   #7
Site Team
norty1's Avatar
Join Date: Jan 2011
Location: James Island, SC
Posts: 22,857
All you can do is keep water in the tank, limit grease and large chunks of food from going down the drain.

I put some dawn and water softener in there with a couple gallons of water after dumping to slosh around.

They are woefully inaccurate and most just ignore them. I don't trust them even when showing empty.
2011- 351RLTS Eagle, MorRyde suspension/pin box,
2017- F350 6.7 PSD Lariat FX4,SRW, SB,CC
Gator roll-up bed cover
B&W Turnover ball, Companion Std hitch
Can't find what you're looking on JOF? Try Jayco Owners Forum Custom Google Search
norty1 is offline   Reply With Quote
Old 05-17-2019, 09:43 AM   #8
Join Date: Jan 2019
Location: North Port
Posts: 44
Do what I am about to do.
Replace them with Valterra T21302VP Horst Miracle Probe - Gray Water Tanks, Pack of 4.
I ordered them from Amazon.
Here is a really good video on hoe to install them:
KregChar is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

This website is not affiliated with or endorsed by Jayco, Inc. or any of its affiliates. This is an independent, unofficial site.

All times are GMT -6. The time now is 01:48 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.