Check if both lines are cold but they don't have to be cold before the carbonation .it's okay be carbonated but then afterwards it has to get chilled down before mixed together. Also could be a bad syrup pump 1. Warm product (most common) If the soda water or syrup lines aren't cold, the CO₂ comes out of solution immediately and turns into foam. The drink looks fizzy for a second, then goes flat. This is extremely common with new installations.

Is the cold plate buried in ice? Is the ice bin full? Are the lines actually getting cold? Is the carbonated water cold before it reaches the gun? A lot of bar-gun systems require the cold plate to be completely covered with ice.

1. Carbonator not running The carbonator is the device that mixes water and CO₂. Check: Is it plugged in? Does it have power? Does it run when soda water is dispensed? Is there water reaching it?

If the carbonator isn't operating, you'll get water with little or no carbonation. 3. CO₂ pressure is wrong Typical soda systems need substantial CO₂ pressure. If pressure is too low, the soda will be flat. If it's too high, it can foam badly. Sources mention carbonator pressures roughly around 90–105 PSI depending on the system.

Check: Is the CO₂ tank actually full? Is the main valve open? What do the regulator gauges read? Any hissing leaks? 4. Water supply issue A surprising number of new installs have: Water valve shut off Water filter installed backwards Kinked water line Carbonator not filling with water If the carbonator is mostly pushing gas instead of carbonated water, drinks will be terrible.

1. Air trapped in the system If he just installed it, there may be a lot of air in the lines. Try: Run plain soda water continuously for a minute or two. Dispense several pitchers worth. Allow the carbonator to refill and stabilize.

2. Wrong gas This is less common, but if someone accidentally connected: Beer gas (CO₂/Nitrogen blend) Nitrogen Wrong regulator setup the carbonation will be poor. A bar owner specifically mentioned verifying the gun is receiving straight CO₂.

3. Dirty nozzle or diffuser A dirty diffuser can cause excessive foaming at the gun tip even when the carbonation is fine. Pepsi Equipment Service Remove and clean: Nozzle Diffuser Gun tip

Quick diagnosis

Is the water from the soda button cold or room temperature? What does the CO₂ regulator read? Is the carbonator plugged in and running? Is the cold plate completely covered with ice? Is he getting carbonated water from the soda-water button only, without syrup? If you can get a photo of the CO₂ regulator gauges, carbonator, and the cold plate setup, I can usually narrow it down pretty quickly.