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

Go Back   Thor Forums > Thor Motorcoach & Motorhome > Class A Motor Coach
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 10-20-2017, 08:20 PM   #1
Senior Member
 
Brand: Thor Motor Coach
Model: outlaw 37ls
State: Europe
Posts: 230
THOR #6831
losing fresh water from tank?

LOSING FRESH WATER? my 37LS has a 100 gal fresh water tank, being a newer owner i was concerned with high water usage and poor reading tank gage.
well here is another design issue, the 100 gale fresh water tank can and will start a siphoning action losing 25-30gal under these conditions.

when the tank is filled to overflow ( i like to do this) and or just about any level over 75 gal. the tank will begin to siphon water from the tank, driving and sloshing the water to the over flow, filling the tank to overflow,
this is aggravated by the fact that the top of the water tank will collapse inward to keep pressure on the siphon action.

it seems the top of the tank is not strong enough to resist the vacuum of the siphon action. ( i have heard that some thor models and others may have a piece of wood shoved in the water tank to support the roof of the tank
would i want a piece of wood in my water tank?

i solved this loss of water by installing a air vent in the overflow hose.
it is a cheap fix some pek tubing and hose clamps. i connected the 2 overflow tubes into a tee fitting with a short upward vent ( about 4") this has stopped all loss of water.
Attached Thumbnails
Click image for larger version

Name:	DSCF0412.jpg
Views:	151
Size:	79.5 KB
ID:	7416   Click image for larger version

Name:	DSCF0413.jpg
Views:	136
Size:	83.0 KB
ID:	7417  


__________________
captmetal is offline   Reply With Quote
Old 10-20-2017, 09:22 PM   #2
Senior Member
 
Travelin' Texans's Avatar
 
Brand: Redwood
Model: 36FB
State: Arizona
Posts: 1,766
THOR #3610
If it's like most fresh water tanks, one of those lines is a vent, the other an overfill. On most the vent is supposed to be attached to the small screened port next to the fill port, but Thor engineers in their infinite wisdom choose to run it out below so as not to make a mess in the convenience center. Their fix for siphoning was to add pipe to that line & loop it up higher, it works. Mine both go out the bottom so I just added pex valves to both lines & have remember to open both while filling, when it starts to siphon close that valve,
continue filling til it comes out the vent, once I've used a bit out of the tank I open the vent.
__________________
Fulltimed 10+ years
Sold '13 Thor Redwood 36 FB
Traded '13 GMC Denali DRW D/A
Replacement undetermined
Travelin' Texans is offline   Reply With Quote
Old 10-20-2017, 09:45 PM   #3
Senior Member
 
Brand: Thor Motor Coach
Model: Challenger 37KT
State: Texas
Posts: 235
THOR #1183
Re poor tank reading gauge. Redneck workaround if side of tank can be seen - fill tank - drain into 5 gal bucket - stop and mark new water level with sharpie and repeat till empty. Start at bottom mark and label 5 gal. next mark 10 gal etc.
__________________
ctpres is offline   Reply With Quote
Old 10-20-2017, 10:41 PM   #4
I Think We're Lost!
 
Bob Denman's Avatar
 
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
Glad to hear that you found a good fix for this! Congratulations!
__________________
"What: me worry?"
Good Sam Member 843599689
Current coach: Tiffin Wayfarer 24 BW
Bob Denman is offline   Reply With Quote
Reply

Thread Tools
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

Disclaimer:

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




All times are GMT. The time now is 05:21 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2