Remove the 1.8-litre water tank from your Philips 5500 LatteGo and fill it with fresh water to the MAX marking. Reinsert the tank firmly, pushing it fully into position. An incorrectly seated tank can allow air into the water circuit and prevent normal pumping. Check whether the water tank warning appears on the display before attempting another drink.

The AquaClean filter is a common cause of restricted water flow on the Philips 5500. Remove the filter from the water tank, refill the tank and select hot water from the machine's drink menu. Place a container beneath the hot water outlet and attempt to dispense water. If water flows normally without the filter, the filter may be blocked or incorrectly prepared. Replace the filter if it has been in use for three months or longer.

If your Philips 5500 makes a loud pumping noise but delivers little or no water, air may be trapped inside the hydraulic circuit. Switch the machine off and back on. With the water tank correctly fitted and the AquaClean filter temporarily removed, select hot water and attempt to dispense 2–3 cups. If Error 05 appears, this indicates air in the water circuit. Do not continue repeatedly running the pump if no water is being drawn through.

Before reinstalling the AquaClean filter, shake it for approximately five seconds, then immerse it upside down in cold water and shake or press it to release trapped air. Insert it vertically into the water tank and push it firmly onto its connection. On the Philips 5500 touchscreen, select Clean → AquaClean → OK, confirm the activation screen and follow the instructions. Remove LatteGo if attached, position a container beneath the hot water outlet and start the activation process. Water should dispense for approximately one minute.

If hot water dispenses normally but coffee does not, inspect the removable brew group. Switch off the machine, allow it to finish shutting down, open the service door and remove the brew group using the PUSH release. Rinse it thoroughly with lukewarm running water, allow it to air-dry and reinstall it correctly. Check the coffee dispensing openings for accumulated coffee residue and carefully clear any obstruction. A dirty brew group or blocked coffee outlet can restrict coffee delivery even when the water pump is operating.

Restricted water flow can also result from limescale inside the Philips 5500 hydraulic circuit. Open the Clean menu and check whether descaling is required. Follow the complete on-screen descaling programme using a suitable coffee machine descaler, removing the AquaClean filter before starting. Error 05 is particularly relevant to pumping problems because it identifies air in the water circuit. If the machine still cannot dispense hot water after the tank, filter and air-lock checks, an internal water supply, pump or hydraulic component fault may require professional inspection.