Thor Forums

[captmetal]

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.