Fresh water tank shut-off - Thor Quantum LH26

[VH1982]

Went to fill my tank today, and it almost immediately started flowing out the overflow/drain.

The manual is totally useless, as far as I can tell. Where/how do I close it so I can fill the tank?

Thanks!

[THenne1713]

Find your three low point drain valves and close them? LOOK UNDER/ AROUND WHERE EVER THE WATER is coming from? ONLY YOU can do this. If WATER IS COMING OUT THE VENT, THE TANK IS FULL, or vent HOSE has a SAG that needs to be removed, BECAUSE TRAPPING WATER, as VENT connection to tank is at TOP of tank.

[VH1982]

Originally Posted by THenne1713

Find your three low point drain valves and close them? LOOK UNDER/ AROUND WHERE EVER THE WATER is coming from? ONLY YOU can do this. If WATER IS COMING OUT THE VENT, THE TANK IS FULL, or vent HOSE has a SAG that needs to be removed, BECAUSE TRAPPING WATER, as VENT connection to tank is at TOP of tank.

I did look underneath, and can see three tubes facing down where one of them is letting water out. This started happening within a few seconds after starting to fill, after being winterized. So I am ASSUMING that the drain valve was left opened as part of the winterization procedure, but I can't locate it.

As I said, the manual is less than useless. I couldn't get the A/C to start so I was looking for breakers/fuses. The manual just says "check the breaker" with no reference to where it might be. A search on here is where I ended up locating it...

[triplewide]

May not be relevant to your coach, but my drain valve is located at the tank location. My tank is located in a compartment under the coach. Previous valves were with the tank located under the bed.

[VH1982]

Found it! Called the dealer. It is under the bed. Literally, under the bed. Have to remove (3) combo phillips/square drive (hate those things) and lift a panel to find it, but I did.

Thanks for all suggestions.

[triplewide]

Thanks for posting your solution. Glad you found it.

[THenne1713]

BTW/ TIP: if LOW POINT DRAIN VALVES are white plastic, generally= TURN to Open/Close, but if small Black plastic T-handle= Lift to Open, Push down to close

[jonas007]

What model and year was your for reference?

[VH1982]

Originally Posted by jonas007

What model and year was your for reference?

2021 LH26.

But the dealer confirmed it was the same as on the 2022 LC26 they have on the floor.

[jonas007]

Originally Posted by VH1982

2021 LH26.

But the dealer confirmed it was the same as on the 2022 LC26 they have on the floor.

Ah ok, im trying to find mine on a 2011 Thor windsport. Haven’t looked under the bed yet

[1JetDoc]

They're under the bed in ours too.

Our 2015 Citation Sprinter 24ST (rear twin beds) has a small panel under the passenger side rear bed that's held in place with Velcro strips. There are two 1/4 turn valves under there.

Valve placement is still not obvious, as they're not immediately visible. You have to reach back under the bed to find them.

[WileyOne]

Originally Posted by VH1982

Went to fill my tank today, and it almost immediately started flowing out the overflow/drain.
The manual is totally useless, as far as I can tell. Where/how do I close it so I can fill the tank?

As far as I know, there are only 4 entry/exit points to/from your water tank.
1. Filler hose from port on outside of the camper. About 1" in diameter.
2. Air vent hose leads to same fixture as the fill hose. About 3/8" in diameter.
3. Uptake for the water pump. Mine is PEX tubing.
4. Drain port on outside of the camper.

As far as I know, there is no overflow. When the tank becomes full, the water simply can no longer be added through the fill port and it spews everywhere.

The normal fill procedure is to use a garden hose or dedicated fresh water hose at the fill port. As water enters the tank, the air must leave somehow. That is the function of the air vent tube. If the air vent becomes clogged, water from the hose will spill out, just as if the tank is full.

The air vent is a hole about the size of a pencil eraser built into the same plastic fitting as the fill port. Sometimes a mud-wasp will fill it with mud for you. Take a coat-hanger wire and bend the last inch into a tight loop so there are no sharp edges. Then push it into the hole to clear out whatever is blocking the tube. On my unit, the filler tube and vent tube are only about 15 inches long because my water tank is under the forward dinette seat. You may be able to lift the dinette seat to see what is going on.

Whatever crap was clogging the air vent will probably be pushed into the water tank, so you may wish to empty and refill the tank a few times after you clear the problem.

[largo1005]

In my Thor 2022 31W the fresh water drain valve is under the bed. Have to lift mattress, remove plywood panel to get to valve. I installed a hinged door on side of wall under bed for easy access to this valve.
The low point drain valves are located under a drawer under the refrigerator. Had to remove drawer to get to valves. I added two valves to the drain lines under motorhome to eliminate removing the drawer. The valves under the drawer are now left open.

[VH1982]

Originally Posted by WileyOne

4. Drain port on outside of the camper.

Yes. But. The valve the makes it function in mine is under the bed. Have to use a screwdriver to remove the panel covering it.