Inave a Bunn VLPF coffee brewer, water is leaking out of the top of the heating tank when in the breweing cycle. I can seal it with some caulking, but is the top of the heating tank supose to be presurized so water doesn't leak out of the thermostat gasket, high level probe gasket, etc.. Everything else is working fine. Is it the water pressure is too strong?

* Bunn model # for specific solutions.
* Most Pro/Office models have a pre-heated tank.
* Most models (Without Vacation or heater switch) will be heated all the time.
* Care must be taken to keep the inner tank filled.
* Pour cold water into fill tray till water comes out of the brew basket.
* Water will stop coming out of brewer once the tank has been topped off.
* If pot is not able to brew after 20 mins of pre-heating. Then call for service.
* Note; most office and Pro machines used in food establishments are from coffee vendors. The larger machines should be serviced by qualified Bunn service techs.
* Contact your coffee vendor or Bunn service ctr for advice.
Aloha, ukeboy57

The NHS-B has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the thank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

P.S. If you did splash too much water then wipe up as much as you can. Leave it out on a towel or paper towels to allow the excess moisture to evaporate. If you dump all the water out of the brewer (and tank) then you will need to pre-fill it with a pot of water PRIOR to plugging in the brewer. Follow the set up instructions in the manual. Let it heat up and try again. If it's still leaking then there is a hole in the tank. Call for service.

VPR has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the tank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

VPR has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the tank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

The A10 has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the tank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

PS. Check your using the correct size decanter for this brewer. If it's a 10 cup brewer then make sure all the decanters in the office is also 10 cup. Pouring a 12 cup pot into brewer will have 12 cups of coffee come out (over flowing the 10 cup pot.) Note that not all decanters are made the same size. Other brands may be different. Test by filling a pot with water (from faucet) then pouring directly into pot in question. It should match and not under fill nor over fill.

VPR has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the tank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

This is really a home style VPR brewer (but looks nicer)
if you listen to their video (link below) they mention it has a pre-heated tank of water already in the brewer. This means the brewer needs to be pre-filled with a full pot of water and pre-heated prior to using the brewer. Unplugging this unit won't be a problem UNLESS it was emptied of tank water and not refilled when powered up.
* The unit will try and heat up the tank of water but if empty then just air which overheats the unit then blows the thermal fuse. Call for service.
* The warmer is still working but it's not hot enough to brew frequently as the warmer may take up to an hour to get the tank hot enough to brew or it may not get hot at all if it's own thermal fuse blew too.
* Water leaking while the brewer just sits there? Leak in the tank. Call for service.
* water leaks only while pouring? Then your pouring to fast. Wait for the water to drop before pouring in more. If it still leaks even while pouring slowly then there is a leak in the fill tray. Call for service.
* Final; call for service to be safe.
Aloha, ukboy57
https://www.amazon.com/BUNN-Velocity-10-Cup-Coffee-Brewer/dp/B00EAQJCWW/ref=sr_1_1?ie=UTF8&qid=1516431654&sr=8-1&keywords=bunn+nhs+velocity

VPR is a pour over "Volume Displacement" brewer. Required to completely fill the inner tank and heat prior to using brewer. BEFORE plugging in unit, water must be poured into upper tray and with brew funnel and empty pot in place. Keep pouring water into top fill tray until water drips out of brew funnel. Plug in VPR and allow it 15-20 mins to heat up. leave the pot as there may be additional water dripping. Remove power if there is any water spilling out from other places like the top pan cover or bottom of machine. With the initial heating done, take a full pot of water and slowly pour into the top filling tray. HOT steaming water should come out of the brew funnel to fill the (empty) pot. Prep is done and the machine can be used to brew a pot after 10-15mins of reheat time.
*** the machine you have needs to be checked for leaks in areas mentioned above. Water should only come out of brew funnel (if not present then the brew head or if that is missing then the brew pipe. All will need to be replaced prior to brewing.) Leaking under machine is an indication of leak(s) in pour tray,tank,tank cover, gasket, probe gasket. This machine like any used equipment should be checked out by qualified tech prior to use. Be aware that coffee vendors sometimes rent or loan brewers to customers.

if you unscrew the top there's a rubber seal in there that you might have to replace that causes the leaks. also clean your coffee maker regularly with vinegar.
my husband had to replace the seal in ours 4 times but after owning the same Bunn for 20 yrs it was time for a new one

If you are pouring water in the manual brew basin, then check the sprayhead holes, then the spray tube, those could be blocked. If using the auto brew, check the solenoid and or brew switch.