These seals are used when servicing heater components that require separation of the burner, combustion chamber or combustion-air blower assembly. Replacing the disturbed seals helps restore the sealing surfaces needed when the heater is reassembled.

Part 201820990001 is commonly associated with Hydronic D4WSC, D5WSC and D5WS heater models. It may be used during burner replacement, combustion-blower service or other repairs requiring access to the internal heater components.

For more complete Hydronic D4/D5 repairs, this gasket set can be paired with the 252216100000 Hydronic D4/D5 burner, 201819991600 combustion blower, compatible flame and overheat sensors, coolant pumps and heater control units.

Always identify the heater by its complete model, voltage and generation before ordering. Eberspächer has produced several Hydronic D4 and D5 configurations, and similar model names do not guarantee identical replacement parts.

Key Features

• Replacement burner and blower sealing set
• Designed for compatible Eberspächer/ESPAR Hydronic heaters
• Supports burner and combustion-blower service
• Suitable for Hydronic D4WSC applications
• Suitable for Hydronic D5WSC applications
• Suitable for Hydronic D5WS applications
• Helps restore sealing surfaces after heater disassembly
• Supports 12-volt and 24-volt heater applications when otherwise compatible
• Genuine-style replacement part for professional heater service

Specifications

• Part Number: 201820990001
• Formatted Eberspächer Number: 20.1820.99.0001
• Product Type: Burner and blower gasket set
• Primary Function: Sealing serviced heater components
• Heater Type: Coolant heater
• Heater Family: Hydronic
• Compatible Model Families: D4WSC, D5WSC and D5WS
• Voltage Compatibility: Used with compatible 12-volt and 24-volt heater versions
• Installation Location: Burner and combustion-air blower assemblies
• Brand: Eberspächer/ESPAR
• Condition: New replacement part

Compatible Eberspächer/ESPAR Heaters

Part 201820990001 is identified for compatible:

• Hydronic D4WSC heaters
• Hydronic D5WSC heaters
• Hydronic D5WS heaters
• Hydronic D4 and D5 service applications requiring the specified burner and blower seals

Compatibility should be confirmed using the heater identification label or complete heater part number before ordering.

Common Service Applications

This gasket set may be required when:

• Replacing the burner or combustion chamber
• Servicing the combustion-air blower
• Opening the heater for internal cleaning
• Reassembling the heater after burner-system repairs
• Replacing damaged, compressed or deteriorated seals
• Performing a more comprehensive Hydronic D4/D5 service

Important Installation Notes

• Confirm the complete heater model before ordering.
• Confirm whether the heater is a D4WSC, D5WSC or D5WS version.
• Do not reuse a damaged or deteriorated sealing component.
• Inspect the mating surfaces before installing the replacement seals.
• Remove old gasket material without damaging the heater housing.
• Install each seal in its correct position and orientation.
• Confirm that mating surfaces are clean before reassembly.
• Follow the applicable Eberspächer service documentation.
• Test heater operation after completing the repair.
• Heater service should be performed by a technician familiar with diesel-fired coolant heaters.

Related Products

• 252216100000 – Eberspächer/ESPAR Hydronic D4/D5 Burner
• 201819991600 – Eberspächer/ESPAR 12V Combustion Blower
• 251920370000 – Eberspächer/ESPAR Hydronic D5 Flame Sensor
• 2522190123002 – Eberspächer/ESPAR Overheat Sensor with Cable
• 252118250000 – Eberspächer/ESPAR Hydronic D5 24V Coolant Pump
• 252219250000 – Eberspächer/ESPAR 12V Preassembled Pump
• 221000700006 – Eberspächer/ESPAR Coolant-Pump O-Ring
• 225201040011 – Eberspächer/ESPAR Hydronic D5 12V Control Unit
• 225202011001 – Eberspächer/ESPAR Hydronic D5 24V Control Unit
• DH-E2000-MAINT – Eberspächer/ESPAR D5 12V Maintenance Kit