Worcester Bosch Plate Heat Exchanger Greenstar C-PHE 18 87186429480

The Worcester Bosch 87186429480 is a plate heat exchanger, listed by the manufacturer as the C-PHE 18, used across the Greenstar combination boiler range. It sits between the primary circuit and the domestic hot water circuit, transferring heat from the boiler water into the mains-fed hot water supply without the two ever mixing. Because the circuits are separated by the plate stack, the domestic hot water stays at mains pressure and contamination on one side cannot cross to the other.

• Domestic hot water runs hot then cold, or the temperature at the tap fluctuates instead of holding steady
• Reduced hot water flow rate, or the boiler failing to reach and maintain its set temperature
• Water weeping from the plate stack or from the connections around the exchanger
• Scale or system debris blocking the plate passages, which shows up as poor heat transfer and unusually high return temperatures
• Repeated overheat or lockout faults traced to restricted flow through the exchanger

• Check the GC number and the appliance data plate to confirm this exchanger suits your model.
• The alternative part number 1031161 may be listed in place of 87186429480.
• Check whether new seals or gaskets are required for the appliance before fitting.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.