It only makes 1/2 pot when I pour the water in after sitting over night some times it takes 2 pot of water or more to make a full pot

VPS/VPR are pour over brewers. Like the 12 cup brewers you find at home, they need to be filled with 12 cups of water (a full pot), heated and then peculated over the coffee grounds and collected in a decanter.
BUT there is one main difference! The VPR and similar COMMERCIAL coffee machines are quick brewers. They usually have a pre-heated pot of water stored inside the machine.
* VPR's and similar machines REQUIRE a pre-fill and heating period prior to brewing. This means it's sitting on a level table and filled with water until water sprays from the brew head. At this point the unit is plugged in and the heater is turned on (there may be some water discharge from brew head as the water expands). Ready light will come on in about 15 mins.
* To Brew; Place coffee grounds in filter, place in funnel and brew head, clean empty decanter under funnel, slowly pour one full decanter of water (cold or hot) into brew tray. Do not overflow tray. Allow water level to sink before adding more water. Only fill with one pot as an equal amount will come out the brew head and funnel.
* Make sure the decanters are all the same size. do not mix a 12 cup pot with a 10 cup pot. One will over fill and the other will under fill. Make sure they match (in cup volume) FYI; Thermo Air pump pots are usually bigger than one pot. Typical filling only to 3/4th of the container. (I think most are in 2.5 to 3 liter sizes)
* If your not getting a full pot then the brewer was partially empty. The second brew (if done within the next hour) should come out full.
* If your still not getting a full pot then the water is leaking or is boiling off. Does it always steam from the top? Thermostat is shorted. Unplug the brewer and call vendor for service.
* Final; If your unplugging when not in use. Then follow the Pre-heat instructions mentioned above prior to plugging the brewer back in. If the tank has been emptied at night or dried up after an idle week. Then there is a chance you may over heat and blow the thermal fuse. Or at best have a half pot short brew as the water dried up.
* Note leaving the brewer plugged in without brewing daily is not a good idea. The water evaporates and eventually drys out the pot. Takes about 1-2 weeks but it does blow the fuse(s) and the unit will need service.
* Final; Follow the Bunn set up and care instructions (manuals from Bunn.com for down loading. *FREE*)
Aloha, ukeboy57

VPS/VPR (VP17-3 are the same except it has 3 lower warmers) are pour over brewers. Like the 12 cup brewers you find at home, they need to be filled with 12 cups of water (a full pot), heated and then peculated over the coffee grounds and collected in a decanter.
BUT there is one main difference! The VPR and similar COMMERCIAL coffee machines are quick brewers. They usually have a pre-heated pot of water stored inside the machine.
* VPR's and similar machines REQUIRE a pre-fill and heating period prior to brewing. This means it's sitting on a level table and filled with water until water sprays from the brew head. At this point the unit is plugged in and the heater is turned on (there may be some water discharge from brew head as the water expands). Ready light will come on in about 15 mins.
* To Brew; Place coffee grounds in filter, place in funnel and brew head, clean empty decanter under funnel, slowly pour one full decanter of water (cold or hot) into brew tray. Do not overflow tray. Allow water level to sink before adding more water. Only fill with one pot as an equal amount will come out the brew head and funnel.
* Make sure the decanters are all the same size. do not mix a 12 cup pot with a 10 cup pot. One will over fill and the other will under fill. Make sure they match (in cup volume) FYI; Thermo Air pump pots are usually bigger than one pot. Typical filling only to 3/4th of the container. (I think most are in 2.5 to 3 liter sizes)
* If your not getting a full pot then the brewer was partially empty. The second brew (if done within the next hour) should come out full.
* If your still not getting a full pot then the water is leaking or is boiling off. Does it always steam from the top? Thermostat is shorted. Unplug the brewer and call vendor for service.
* Final; If your unplugging when not in use. Then follow the Pre-heat instructions mentioned above prior to plugging the brewer back in. If the tank has been emptied at night or dried up after an idle week. Then there is a chance you may over heat and blow the thermal fuse. Or at best have a half pot short brew as the water dried up.
* Note leaving the brewer plugged in without brewing daily is not a good idea. The water evaporates and eventually drys out the pot. Takes about 1-2 weeks but it does blow the fuse(s) and the unit will need service.
* Final; Follow the Bunn set up and care instructions (manuals from Bunn.com for down loading. *FREE*)
Aloha, ukeboy57

You should be able to pick up a replacement/new pot at your nearest Restaurant Supply store. Make sure you get a 64 oz./ 1/2 gallon pot.
Before plugging in your brewer, unscrew the sprayhead located just above where the filter basket sits and replace the basket, pour 3 pots of cold water through the opening on the top if the brewer is empty. This brewer has a reservoir that holds about 2 1/2 pots of water at brewing temperature when heated. Make sure you put an empty pot under the filter basket after pouring in the water. Water will flow from the brew basket when the reservoir has reached its capacity. Once water flows you can then plug in and energize your brewer and replace the sprayhead. It will take about 15 to 20 minutes for the brewer to reach brew temp, you will hear the heating stop. Put an empty filter and a dose of coffee (I recommend starting with a heaping measuring cup of drip ground coffee) into the filter basket, lightly shake it level, replace the basket and pour through 1 full pot of COLD water in the top. For best results pour the brewed coffee into a pre-heated thermal server if you plan on holding the coffee for more than 10 minutes or so.
Enjoy!

The tank inside holds about 2 and a hlalf pots of water. Once the tank is full, whatever you pour in will come out. The unit has to be plugged in to make coffee. Leave a pot under the brew funnel and pour a pot of water in. If nothing comes out within a minute, pour another pot of water in. Still if nothing comes out do it again. This time for sure water will come out. It will take avout 10 minutes to get hot enough the first time it is full to make coffee. If you have a thermometer, the water should be about 190 degrees F to make coffee correctly.

With the machine full of water and still turned on, pour in 1 qt of white vinegar into the top and place decanter on base and close the lid. You will let this sit in the machine for 2 hours. At the end of 2 hours, flush out the vinegar with 8-10 decanters of water.

If you pour water into the machine, and water comes out, then the reservoir is full of water. There is no way the water can bypass the reservoir and go directly into the pot.

The machine is always on, so it is never full the first time you use it on monday. Try this before you use it on monday pour in a full pot of water in the brewer and put an empty pot under the head. Wait about 7 minutes, the machine will fill the tank and then be ready for brewing coffee.

This coffee maker uses a resevoir tank system - the water you pour in pushes out water that is already heated - the water you pour in won't actually be used for that pot of coffee! For that reason you should only use full pitchers when filling. You may need to cycle through 2 or 3 fillings before the input matches the output once more. The capacity of the resevoir is about 3 pitchers; you can brew 2 pots in a row before the machine needs a break to bring the resevoir back up to temperature.

I had the exact same problem with my machine making 1 cup at a time.

Here is the solution: 

1. make solution of 1 part vinegar & 2 parts water.

2. pour solution into resivoir and set for 2 hours

3. run solution through machine (yes, you will have to stand there and keep pushing the buttons).

4. take same solution (now very hot) and run it through machine 5 or 6 times

5. make fresh solution and continue process

I had the exact same problem with my machine making 1 cup at a time.

Here is the solution: 

1. make solution of 1 part vinegar & 2 parts water.

2. pour solution into resivoir and set for 2 hours

3. run solution through machine (yes, you will have to stand there and keep pushing the buttons).

4. take same solution (now very hot) and run it through machine 5 or 6 times

5. make fresh solution and continue process until machine runs full cycle.