3" Heavy Duty Vinyl Bilge Blower Hose - 420-3

What This Blower Hose is Used For

Item 420-3 is used in compatible 3" marine ventilation systems to route air between the blower, engine compartment and exterior ventilation openings.

Typical applications include:

• Bilge blower ducting
• Engine-compartment ventilation
• Powered exhaust ventilation systems
• Replacement of damaged or deteriorated 3" blower hose
• Marine air-intake and exhaust duct routing

Matching 3" Bilge Blower

Moeller 3" Bilge Blower - 5-3710

Matching 3" marine bilge blower for compatible engine-compartment ventilation systems. Pro Marine lists 5-3710 as a Moeller aftermarket blower. :contentReference[oaicite:0]{index=0}

Use 3" blower hose with a ventilation system designed around 3" ducting unless the boat manufacturer specifies otherwise.

View 3" Bilge Blower

Matching 3" Hose Clamp

German-Style Hose Clamp - 4-13

Matching clamp for securing 3" blower hose to compatible blower outlets and ventilation fittings.

A secure clamp helps keep the hose attached and prevents the duct from slipping off due to vibration or movement inside the boat.

View 4-13 Hose Clamp

3" and 4" Marine Blower System Guide

Need 4" Blower Hose Instead?

4" Heavy-Duty Vinyl Blower Hose - 420-4

Larger 4" marine ventilation hose for systems designed around a 4" bilge blower and ducting.

View 4" Blower Hose

4" Bilge Blower - 5-3715

Matching 4" blower option for marine ventilation systems requiring 4" ducting.

View 4" Bilge Blower

German-Style Hose Clamp - 4-17

Matching clamp for compatible 4" marine blower hose installations.

View 4-17 Hose Clamp

Why Bilge Ventilation Matters

Enclosed gasoline engine compartments can accumulate fuel vapors. A properly designed powered ventilation system helps exhaust those vapors from the compartment before engine startup.

Blower hose is an important part of that system because it directs airflow to and from the areas the ventilation system is intended to serve.

Damaged, disconnected, crushed or badly routed ducting can reduce the effectiveness of the ventilation system even if the blower itself is working.

Blower Hose Installation Tips

• Use hose that matches the blower and vent fitting diameter.
• Secure connections with the proper hose clamp.
• Keep hose runs as short and direct as practical.
• Avoid sharp bends, crushed sections and kinks.
• Support the hose so it does not sag into bilge water.
• Keep duct openings clear of stored gear and debris.
• Inspect old hose for cracking, tearing or collapsed sections.
• Verify airflow after replacing the blower or ducting.

When Should Blower Hose Be Replaced?

Inspect the ventilation ducting whenever the blower is serviced or the engine compartment is being worked on.

Replace blower hose if you find:

• Tears or holes
• Cracking or age-related deterioration
• Collapsed sections
• Severe kinks
• Loose connections
• Hose that will no longer stay attached to fittings
• Damage caused by stored equipment or engine-compartment heat

Marine Wiring Supplies

If you are replacing the blower and hose together, inspect the blower wiring at the same time.

Blue Butt Connectors - BBC - 25 Pack

Electrical butt connectors for compatible marine blower and wiring repairs.

View Blue Butt Connectors

1/4" Red Heat Shrink - 14R

Red heat-shrink tubing for protecting compatible electrical connections and identifying positive wiring.

View Red Heat Shrink

1/4" Black Heat Shrink - 14B

Black heat-shrink tubing for protecting compatible electrical connections in marine installations.

View Black Heat Shrink

Key Features and Benefits

• 3" diameter marine blower hose
• Heavy-duty vinyl construction
• Designed for compatible bilge ventilation systems
• Useful for engine-compartment intake and exhaust ducting
• Matching Moeller 3" bilge blower available
• Matching German-style 4-13 clamp available
• Complete 4" blower system also available
• Marine wiring supplies available for blower replacement projects

FAQ

What size is blower hose 420-3?
Item 420-3 is 3" marine blower hose.

What blower works with this hose?
Pro Marine stocks the Moeller 5-3710 3" Bilge Blower for compatible 3" ventilation systems.

Which clamp should I use?
Use the German-Style 4-13 Hose Clamp for this 3" blower hose.

Why is blower hose important?
The blower creates airflow, while the hose directs that airflow through the engine-compartment ventilation system. Damaged or collapsed ducting can reduce ventilation performance.

Can I use this hose on a 4" blower?
No. Use hose that matches the blower and ventilation fittings. For a 4" system, use item 420-4 4" blower hose .

Should blower hose have sharp bends?
Avoid sharp bends and kinks whenever possible because they can restrict airflow through the ventilation system.

Do you stock the complete 3" blower setup?
Yes. Pro Marine stocks the 3" blower, 420-3 blower hose and 4-13 clamp.

Do you carry blower wiring supplies?
Yes. Pro Marine stocks blue butt connectors, red heat shrink and black heat shrink.

Searchable Terms

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