My bunn coffee ,coffee taste like metal I cleaned it with vinger

Try really cleaning the basket that the water and coffee or cocao goes into. If you don't really clean it well, it will have the taste of the last thing brewed mixed in with the new brew. Coffee followed by coffee should not be a problem, but coffee followed by cocao will give the cocao a coffee taste, and visa versa.

remove tank from machine seperate lid from tank (remeber where everything goes and be very careful not to tear a gasket) descale with a descaling liquid or clean out what ever foriegn substance is in tank. If tank is clean then i would make sure it is getting hot enough when you brew as brewing to low will make coffee taste awful. also make sure you have a sprayhead on the machine to properly saturate all the grounds.

run some vinger and water through it a few times then try it out again.

Believe it or not I had a customer once that left 6 pounds of butter on top of one of our brewers. They had it cleaned up on the outside so it took me a while to figure out what had happened but I could taste the rancid oils.
We ran about 20 pots of just water through it... make sure you let it heat back up before each one. I think the only thing vinegar might help with would be lime/calcium build up so I wouldn't think it helps this particular situation.
Good luck!

mcdevito75 here, Contact Bunn for their recommended cleaning material for your coffee maker, or see any large store that carries coffee makers for their cleaning kits.

You will pour 1 quart of white vinegar in where you would normally put water to brew coffee. This should be done with the machine on and full of water. Please let this sit in the machine for 2 hours and then flush out with 8-10 decanters of water.

You will need to pull you coffee maker out and take the top off and clean inside the water tank. Someone has put coffee from pot of old cold pot of coffee back threw. or something loke this. just clean inside and out. clean coffee maker and pots. hope this helps
Have a cup on old saw

you can always clean a coffeemaker with vinegar, but always pour in cold, so you can do it twice or more, but dont re-use the stuff you just used, wait till it's cold or just use some other.after use clean by let water through 2 or 3 times, (also only cold water)

Check your water supply lines if your unit is hooked directly into a water supply. Your unit either has to be cleaned (de-limed) or your water source is bad. You could try using filtered water, but if you have residue inside the unit it must be flushed with a professional delimer if white vinegar doesn't do the trick.

Use the de-liming spring to clean the copper tube behind the spray head. Pour several pots of clear white vinegar through the unit to further remove lime and scale from the interior of your coffee maker. My Bunn is 24 years old, and the only replacement parts I've ever required are new carafes and the 4041 silicone washer repair kit.