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Heater flaps

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DISPLAYING 1 to 16 (of 33 products)
1 2 3
64421125100KIT
Product Information
Product Information
Heater box clamp with bolt, nut and lock ring. One complete clamp. 2 required per car.

porsche

Fits:
Porsche 356 / A 1950-59
Porsche 356 B / C 1960-65

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

64421125100KIT
64421125100
PCG0120072
PCG21125100
PCG02214812
PCG07401401

The product you are viewing cross references to these numbers
Special Order item
64421100
Product Information
Product Information
Heater Box. Porsche 356C REUTTER / KARMANN
porsche

Fits:
Porsche 356C 1964-65
COUPE -REUTTER-
COUPE -KARMANN-

Click 'Zoom in' for large parts diagram.
Diagram ref no 1

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Related, superseded, cross reference or alternative numbers for comparison.

64421100
64421100707
64421100807

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61610604
Product Information
Product Information
Air duct engine
These OE Match engine air ducts are replacement engine cooling air duct components for Porsche 356A, 356B, and 356C models. They are available for left and right side positions and are designed to match the original-style fitment and function within the engine cooling system.
Left and Right Sides – Sold Separately

Fits:
Porsche 356A 1955 - 1959
Porsche 356B 1959 - 1963
Porsche 356C 1963 - 1965

Section of diagram ref no 30 

The engine air duct helps direct cooling air through the engine compartment and over the correct engine areas. Properly fitted air ducts are important for maintaining efficient air-cooled engine temperature control and supporting reliable engine operation.

Functions
  Replaces the engine air duct
  Helps direct cooling air through the engine bay
  Supports correct air-cooled engine temperature control
•  Helps maintain factory-style cooling airflow
  Replaces missing, cracked, corroded, dented, or damaged original ducts
  Suitable for engine rebuilds, cooling system work, and restoration
  OE Match replacement for classic Porsche engine cooling repair

Why Replace This Part?
Engine air ducts can become damaged, dented, corroded, cracked, loose, or missing due to age, heat, vibration, previous engine repairs, or restoration work. A damaged or missing air duct can reduce cooling efficiency, disrupt airflow, and leave the engine bay incomplete. Replacing the duct helps restore correct airflow and original-style engine compartment detail.

When to Replace This Part
  The original air duct is missing, cracked, corroded, or damaged
  Cooling air ducting is incomplete or incorrectly fitted
  Engine cooling performance is being inspected
  The engine has been removed, rebuilt, or restored
  Engine bay tinware or ducting is being replaced
  Incorrect or mismatched ducting has been fitted
  The vehicle is undergoing Porsche 356 engine bay restoration.

Where it fits on the car
These air ducts fit within the engine cooling air ducting system on Porsche 356A, 356B, and 356C models. One duct is used for one side of the engine bay, and the other is used for the opposite side, depending on the part selected.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

61610604
61610604100
61610604200

The product you are viewing cross references to these numbers
Special Order item
PCG07401401
Product Information
Product Information
Bolt for box clamp.

porsche

Fits:
Porsche 356 / A 1950-59
Porsche 356 B / C 1960-65

Click 'Zoom in' for large parts diagram.
Diagram ref no 3

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Related, superseded, cross reference or alternative numbers for comparison.

PCG07401401
PCG07401401
64421125100

The product you are viewing cross references to these numbers
Special Order item
PCG35621100
Product Information
Product Information
Clamping sleeve set for heating filament.


porsche

Fits:
Porsche 356 A/B/C (1950 to 1965)

Click 'Zoom in' for large parts diagram.
Diagram ref nos 5, 6, 7, 8.



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PCG35621100
PCG35621100

The product you are viewing cross references to these numbers
53906541/1
Product Information
Product Information
Flapper box spring.

original

Fits:
Porsche 356 50-65

Click 'Zoom in' for large parts diagram.
Diagram ref no 31

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53906541
53906541
539-06-541

The product you are viewing cross references to these numbers
64457269
Product Information
Product Information
Fresh air outlet hose, under dash.

oematch

Fits:
Porsche 356 B T6 / 356C 1.6 08/1962-12/1965

Click 'Zoom in' for large parts diagram.
Diagram ref no 39

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

64457269
64457269106
64457269206

The product you are viewing cross references to these numbers
Special Order item
PCG21125100
Product Information
Product Information
Heater box clamp.

porsche

Fits:
Porsche 356 / A 1950-59
Porsche 356 B / C 1960-65

Click 'Zoom in' for large parts diagram.
Diagram ref no 3

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PCG21125100
PCG21125100
64421125100

The product you are viewing cross references to these numbers
64421175100/1
Product Information
Product Information
Heater box control sleeve.

oematch

Fits:
Porsche 356 A (NOT for Carrera)
Porsche 356 B
Porsche 356 C

Click 'Zoom in' for large parts diagram.
Diagram ref no 8

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64421175100
64421175100

The product you are viewing cross references to these numbers
53906644/1
Product Information
Product Information
Flapper Box Spring single flap (early style).

original

Fits:
Porsche 356, 356A

Click 'Zoom in' for large parts diagram.
Diagram ref no 32

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53906644
53906644
539-06-644

The product you are viewing cross references to these numbers
64421192100/1
Product Information
Product Information
Heater box vent hose 50x130mm. 

oematch

Fits:
Porsche 356 - 1950 to 1955
Porsche 356A - 1555 to 1959
Not for Carrera

Heater box vent hose 50x130mm. 

Click 'Zoom in' for large parts diagram.
Diagram ref no 1




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64421192100
64421192100

The product you are viewing cross references to these numbers
64421192105/1
Product Information
Product Information
Heater box vent hose 50x270mm
This OE Match heater box vent hose is a replacement flexible heater air hose for Porsche 356 and 356A models. Measuring 50 x 270 mm, it is designed to match the original-style fitment and function within the classic Porsche heating and ventilation system.
Sold each - 2 required per car

Fits:
Porsche 356 1950 - 1955
Porsche 356A 1555 - 1959
Not for Carrera

Diagram ref no 1

The heater box vent hose carries warm air from the heater box into the ventilation ducting system. A correctly fitted hose helps maintain proper airflow, cabin heating, and windscreen demisting performance.

Functions
Replaces the heater box vent hose
 Carries warm air through the heater and ventilation system
 Supports cabin heating and demisting performance
 Helps maintain correct heater airflow
 Replaces split, crushed, brittle, missing, or heat-damaged hoses
 Suitable for heating system repair or restoration
 OE Match replacement for Porsche 356 heater system refurbishment.

Why Replace This Part?
Heater vent hoses can become brittle, split, collapse, fray, or detach due to age, heat, moisture, vibration, and general wear. A damaged hose can reduce warm air flow, cause poor demisting, allow air leaks, or leave the heater system incomplete. Replacing the hose helps restore correct heater operation and original-style presentation.

When to Replace This Part
  The heater hose is split, crushed, brittle, torn, or missing
  Cabin heating output is weak or uneven
  Windscreen demisting performance is poor
  Air leaks are present around the heater box or ducting
  The heater boxes or ventilation ducting are being serviced
  Engine bay or underside heater components are being restored
  The vehicle is undergoing Porsche 356 or 356A restoration.

Where it fits on the car
This hose fits within the heater box vent and warm air ducting system on Porsche 356 and 356A models. It connects according to the factory heater layout and supports airflow from the heater box into the ventilation system.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

64421192105
64421192105

The product you are viewing cross references to these numbers
35655120
Product Information
Product Information
Heater box vent hose stainless steel.

Fits:
Porsche 356 - 1950 to 1955
Porsche 356A - 1555 to 1959
Not for Carrera


Flexible Stainless Steel (approx 140mm )

Diagram ref no 1



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

35655120
64421192100
64421192105
35655120

The product you are viewing cross references to these numbers
64421102100/200
Product Information
Product Information
Heater box, Black Powder Coated, PAIR.

The OE MATCH Heater Box, Black Powder Coated, Pair is a high-quality replacement set of heater boxes designed for classic Porsche heating systems. These heater boxes surround the exhaust heat exchangers and capture heat generated by the engine's exhaust system, directing warm air into the cabin through the vehicle's heating and ventilation ducts.

Fits:

  • Porsche 356A 1955-59

Diagram Ref No 2

Finished in a durable black powder-coated coating, these heater boxes offer enhanced corrosion resistance, improved durability, and an original-style appearance. Manufactured to OE specifications, they provide proper fitment, efficient heat transfer, and reliable operation, making them ideal for restoration projects or replacing corroded and damaged original units.

What This Product Does:

  • Captures heat generated by the exhaust heat exchangers
  • Directs warm air into the cabin heating system
  • Provides efficient cabin heating and demisting performance
  • Helps maintain passenger comfort in cold weather
  • Protects heating system airflow around the heat exchangers
  • Supports proper operation of the vehicle's heating and ventilation system

Symptoms Of Wear Or Failure:
  • Poor cabin heating performance
  • Reduced airflow from heating vents
  • Rust, corrosion, or perforation of the heater box housing
  • Heat loss before warm air reaches the cabin
  • Exhaust fumes entering the heating system
  • Rattling or vibration from damaged housings
  • Uneven cabin temperatures Visible deterioration of heater box components

Why Replacement Matters:
  • Restores efficient cabin heating performance
  • Improves airflow and heat delivery to the passenger compartment
  • Helps prevent heat loss within the heating system
  • Reduces the risk of exhaust fumes entering the cabin
  • Protects heat exchangers and heating system components
  • Improves vehicle comfort during cold weather operation
  • Supports accurate restoration of classicPorsche models
  • Provides long-term corrosion resistance and durability with black powder-coated protection



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

64421102100
64421102100
64421102200
1623200470
1623200480
64421102111
64421102211

The product you are viewing cross references to these numbers
64421102505/605
Product Information
Product Information
Heater Box, Black Powder Coated, Pair.

The OE MATCH Heater Box, Black Powder Coated, Pair is a premium-quality replacement set of heater boxes designed for classic Porsche heating systems. These heater boxes enclose the exhaust heat exchangers and channel heated air into the vehicle's cabin heating and ventilation system, providing effective interior heating, demisting, and occupant comfort.

Fits:

  • Porsche 356B 1959-63
  • Porsche 356C 1963-65  

Diagram Ref No 1

Manufactured to OE specifications and finished with a durable black powder-coated coating, these heater boxes offer excellent corrosion resistance, long-term durability, and an original-style appearance. They are ideal for restoration projects or replacing rusted, damaged, or deteriorated original units, helping to restore heating system efficiency and reliability.

What This Product Does:

  • Captures heat generated by the exhaust heat exchangers
  • Directs heated air into the cabin heating and ventilation system
  • Provides effective interior heating and windscreen demisting
  • Supports proper airflow through the heating system
  • Helps maintain passenger comfort in colder weather
  • Protects and channels airflow around the heat exchanger assemblies

Symptoms Of Wear Or Failure:
  • Poor cabin heating output
  • Reduced airflow from heating vents
  • Rust, corrosion, or holes in the heater box housing
  • Heat loss before warm air reaches the passenger compartment
  • Exhaust fumes entering the cabin heating system
  • Rattling or vibration caused by deteriorated housings
  • Uneven cabin temperatures
  • Visible deterioration or structural damage to the heater boxes

Why Replacement Matters:
  • Restores efficient cabin heating and demisting performance
  • Improves airflow through the heating system
  • Reduces heat loss and improves heating efficiency
  • Helps prevent exhaust fumes from entering the cabin
  • Protects heating system components and heat exchangers
  • Supports accurate restoration of classic Porsche models
  • Provides long-lasting corrosion protection with black powder-coated finish
  • Maintains vehicle comfort, safety, and reliability in all weather conditions



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

64421102505
64421102505
64421102605

The product you are viewing cross references to these numbers
3565501
Product Information
Product Information
Heater box. 

Fits:
Porsche 356 - 1950 to 1955
Not for Carrera


Diagram ref no 2



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

3565501
35655015
356 55015
3565 5016
35655016

The product you are viewing cross references to these numbers
DISPLAYING 1 to 16 (of 33 products)
1 2 3
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About Heater flaps

Porsche Heater Flaps | Precision Airflow Control & Cabin Heating Efficiency

Heater flaps are an essential component in your Porsche’s air distribution and heating system. They control the direction and temperature of air entering the cabin by opening or closing air passages within the ventilation ducts. A properly functioning heater flap ensures balanced temperature control, effective defrosting, and comfortable cabin airflow.

At Design911, we supply high-quality heater flaps and actuators engineered to meet or exceed original performance standards. Each component is designed using durable heat-resistant materials for long-term reliability and smooth operation, ensuring consistent temperature regulation and precise airflow control.

Whether you’re restoring an air-cooled classic or maintaining a modern Porsche climate system, our heater flaps deliver reliable performance, proper sealing, and improved heating efficiency.

What Do Heater Flaps Do?

Heater flaps regulate the distribution and temperature of air in your Porsche’s HVAC system by directing warm or cool air through specific vents.

Core Functions:

  • Control the mix of warm and cool air entering the cabin.
  • Direct airflow to the windscreen, floor, or dash vents as required.
  • Enable quick demisting and defrosting of glass surfaces.
  • Maintain steady interior comfort in all weather conditions.
  • Work in harmony with heater cables or electronic actuators.

Without functional heater flaps, airflow becomes unbalanced — resulting in uneven cabin temperatures, poor ventilation, or ineffective defrosting.

Why Do Heater Flaps Fail or Wear Out?

Heater flaps operate continuously under fluctuating temperatures and airflow pressure. Over time, the mechanisms, seals, or actuators can deteriorate.

Common Causes of Failure Include:

  • Corrosion or rust in metal housings or linkages.
  • Broken flap hinges or worn pivot points.
  • Seized mechanisms from dirt, moisture, or lack of use.
  • Damaged or perished rubber seals causing air leaks.
  • Failed vacuum or servo actuators in electronically controlled systems.

When flaps fail, you may notice inconsistent heating, no airflow from certain vents, or cold air entering the cabin even when the heater is on.

Why Replace Your Porsche Heater Flaps?

Replacing worn or damaged heater flaps restores proper airflow control, prevents heat loss, and improves the overall comfort and efficiency of your heating system.

Key Benefits:

  • Restores balanced airflow and temperature control.
  • Prevents unwanted cold drafts or heat loss.
  • Ensures proper function of demisting and defrosting.
  • Improves cabin comfort in both classic and modern Porsches.
  • Designed for Porsche 911, 912, 914, Cayman, Boxster, Panamera, Macan, and Cayenne models.
  • Perfect for restoration, maintenance, or complete HVAC rebuilds.

Upgrading or replacing old heater flaps also enhances interior air quality and ensures your ventilation system operates as designed.

Highlights

  • Precision-engineered Porsche heater flaps and actuators.
  • Durable, heat-resistant materials for longevity.
  • Direct-fit replacements for Porsche air-cooled and water-cooled models.
  • Essential for consistent airflow and heating performance.
  • Ideal for restoration, maintenance, or upgrade projects.
  • Supports reliable climate control and demisting efficiency.       

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