Home Draught System Troubleshooting Guide

A home draught system can produce foam, flat beer, slow flow or no beer at all when temperature, gas, pressure, lines or the keg connection are wrong. The quickest solution is to check the system in a fixed order instead of repeatedly turning the regulator.

This guide covers full-size keg and home-bar systems. PerfectDraft and Blade machines use their own keg and machine-specific procedures, so follow the relevant manufacturer guidance for those systems.

Start With These Five Checks

1. Beer temperature: Confirm the keg and the full product path to the tap are cold.
2. Correct gas: Check both the gas type and any stated blend ratio.
3. Correct coupler: Ensure the tapping head matches the keg valve and is fully engaged.
4. Clean beer path: Inspect the coupler, line, cooler and tap for residue or obstruction.
5. System pressure: Use the recommendation for the exact beer and equipment only after the first four checks pass.

Why Is My Keg Beer Too Foamy?

Warm beer is one of the most common causes of foam. Cooling the glass does not compensate for a warm keg or an unchilled section of beer line. Check the keg temperature, cooler operation, line route and tap before changing pressure.

Other causes include:

• An overcarbonated keg
• The wrong gas or gas ratio
• Excessive, unstable or recently changed pressure
• A kinked, damaged or incorrectly sized beer line
• A dirty tap, coupler or stout restrictor plate
• Opening the tap only partly instead of fully
• A dirty or warm glass

Open the tap fully and use a clean glass held at roughly 45 degrees. If the problem persists, isolate one variable at a time.

Why Is the Beer Flat?

Check whether the cylinder is empty or closed, whether the regulator is supplying pressure and whether gas is leaking from a connection. Confirm the correct gas for the keg: most carbonated lagers, ales and ciders commonly use CO₂, while Guinness Draught requires 75% nitrogen and 25% CO₂.

Flat beer can also result from applying an unsuitable gas blend or pressure for too long. Read our beer gas versus CO₂ guide before making changes.

No Beer Is Coming From the Tap

Check the following:

• The gas cylinder is open and contains gas
• The regulator valve and any inline shut-off are open
• The keg coupler is fully locked and engaged
• The beer and gas lines are connected to the correct ports
• The line is not kinked, frozen or blocked
• The tap and stout restrictor plate are clear
• The keg is not empty

Never dismantle a pressurised connection. Close the cylinder and safely release downstream pressure before inspecting fittings.

The Beer Is Pouring Too Slowly

A slow pour can indicate low gas pressure, an almost empty cylinder, a restriction, a partly engaged coupler or a frozen section of line. It can also result from line dimensions or resistance that do not suit the system.

Inspect the beer and gas line and line fittings before raising pressure. Increasing pressure against a blockage can make the system unsafe and will not remove the obstruction.

The Beer Is Pouring Too Fast

Check whether the pressure is too high for the beer and line layout, whether a flow-control tap is fully open and whether the line has been shortened or replaced with a larger bore. A fast turbulent pour often becomes foam at the glass.

Return to the equipment or keg supplier's starting recommendation and adjust only in small increments.

Guinness Pouring Problems

For Guinness Draught in Ireland, use:

• 75% nitrogen / 25% CO₂ mixed gas
• 35–38 PSI
• A U-type coupler
• A stout tap with a clean restrictor plate
• Cold beer, normally around 5–7°C unless the equipment instructions specify otherwise

If the head is too large or too small, confirm temperature, gas ratio, pressure and restrictor condition together. Our Guinness keg setup guide covers the complete process.

How to Check for a Gas Leak

Secure the cylinder upright and inspect the regulator, line and coupler connections. Use an approved leak-detection solution on gas fittings and look for growing bubbles. Do not test with a flame. If a fitting leaks, close the cylinder and depressurise the line before reseating or replacing the component.

Bad Taste or Smell From Draught Beer

Dirty beer-contact surfaces can make a fresh keg taste stale, sour or otherwise wrong. Clean the coupler, line, cooler pathway, tap and nozzle using an approved draught-line cleaner, following its exact dilution, contact-time and rinsing instructions.

Do not use household washing-up liquid in beer lines. Replace beer line that remains tainted, damaged or stained after correct cleaning. Browse beer-line cleaning and maintenance products.

Coupler and Connection Problems

A coupler that looks close enough may still be wrong. A, D, G, S and U valves require matching equipment, and different versions can exist within a system. Do not force a coupler onto a keg. Check our keg coupler types guide and inspect the seals before reconnecting.

When to Stop Troubleshooting

Stop and seek help if a gas fitting is damaged, the regulator behaves unpredictably, a cylinder valve leaks, pressure cannot be controlled or you are unsure how to depressurise the system. TheKegCru also offers home-bar service and technical support for suitable systems.