Before cleaning your water cooler, you need to decide which disinfectant to use. If you choose to use vinegar but want to avoid its strong smell, you can add lemon juice.
To prevent a vinegar taste in your water, flush the tank thoroughly after cleaning it — you might need to repeat the process several times to completely remove the taste and smell. Remember to drain the clean water through both spigots to ensure both lines are clear.
If the issue persists, your cooler might require more extensive maintenance or even replacement.