If a water heater’s draft hood is missing, stop using the appliance until it has been inspected and the correct part is installed. A draft hood is part of the venting arrangement on some gas water heaters; a replacement must match the heater and vent configuration, not just look similar. The Rheem AS40665 is the clearest option listed for 3-inch or 4-inch vent connections, while the Bradford White and AO Smith parts may suit buyers confirming those manufacturers’ specifications. Product listings alone do not establish compatibility.
| Product | Best suited for | Listed detail |
|---|---|---|
| Rheem AS40665 ProTech | Buyers checking a 3-inch or 4-inch vent connection | 3-inch and 4-inch vent compatibility |
| Vent Hood | Buyers who can verify the exact part before ordering | Listed as a draft hood |
| Bradford White 243-45787-00 | Buyers matching a Bradford White part number | Named as a 3-inch draft hood connector |
| AO Smith 100111362 | Buyers checking an AO Smith 3-inch-to-4-inch part | Listed as a 3-inch-to-4-inch combo |
| AS40665-A Vent Hood | Buyers comparing a 3-inch or 4-inch connection | Vertical mount; 3-inch and 4-inch connection size |
Rheem AS40665 ProTech Vent Hood
Best for: Buyers whose water heater documentation or a qualified technician confirms the need for a Rheem-compatible draft hood with a 3-inch or 4-inch vent connection.
The listing identifies this part as a draft hood for 3-inch and 4-inch venting systems. It says the hood connects the water heater to the venting system and assists the upward movement of combustion gases. Those details make it the most clearly described option here for a buyer comparing vent diameters.
Why it was selected: Its listed connection sizes and draft-hood purpose are explicit, which makes the product easier to compare against a heater’s specifications than listings that provide little or no detail.
Limitation: A matching vent diameter by itself does not prove that this part fits a particular water heater. Confirm the heater model, manufacturer requirements, and vent arrangement before ordering. Do not use the heater while its required hood is missing.
Vent Hood Draft Hood
Best for: A buyer who has already identified an exact replacement part and can confirm this listing matches it.
The supplied product information describes the item only as a “Draft Hood.” It does not state a brand, connection diameter, mounting details, or compatible water-heater models. This may be a candidate to investigate, but the short description is not enough to establish whether it is an appropriate replacement for a missing hood.
Why it was selected: It is directly categorized as a draft hood, the component named in the search, so it is relevant for comparison when the buyer has additional specifications from the water-heater label or manual.
Limitation: The listing data provided here does not identify the vent size or supported heater models. Avoid choosing it based on appearance or the generic name alone. Ask the seller or a qualified technician to verify the exact part number and fit before purchase or installation.
Bradford White 243-45787-00 Connector
Best for: Buyers verifying a Bradford White replacement by the exact part number and confirming the listed 3-inch connection is appropriate.
The product name identifies this as a Bradford White 243-45787-00, 3-inch draft hood connector. That manufacturer and part-number information gives a buyer a specific reference to compare with the water-heater manual, parts documentation, or identification label.
Why it was selected: The product is explicitly described as a 3-inch draft hood connector and names the manufacturer. For replacement decisions, those identifiers are more useful than a generic “vent hood” description, provided the heater documentation confirms the part.
Limitation: The supplied listing information does not describe other connection sizes or compatible heater models. Do not assume that a 3-inch connector is suitable just because the existing vent appears to be 3 inches. Have the appliance and venting requirements checked before installation, especially when the original hood is missing.
AO Smith 100111362 Draft Hood
Best for: Buyers checking an AO Smith part number for a heater that requires the listed 3-inch-to-4-inch combination.
The supplied description calls this a “DRAFTHOOD, 3″ TO 4″ COMBO.” That makes it relevant to buyers comparing a transition or combination connection, but the short description does not explain installation details or identify specific compatible water-heater models.
Why it was selected: The product is identified as an AO Smith draft hood and states the 3-inch-to-4-inch sizing in its name. Those are useful comparison points when checking manufacturer parts documentation.
Limitation: Do not interpret the size description as universal compatibility with any heater that has a 3-inch or 4-inch vent. Confirm the exact part number and appliance requirements. A missing draft hood is a venting and combustion-safety concern, not simply a cosmetic defect.
AS40665-A 3-Inch/4-Inch Vent Hood
Best for: Buyers comparing a vertical-mount vent hood listing that specifies 3-inch and 4-inch connection sizes.
The listing identifies the item as a vent hood with a 3-inch/4-inch connection size and vertical mount. It also states an overall length of 5.95 inches and lists one piece. These details can help when checking a candidate part against measurements and installation specifications, but they do not establish that it is the right replacement for a particular heater.
Why it was selected: Its stated connection sizes and mounting orientation give buyers more comparison details than a listing that only says “draft hood.” The AS40665-A model reference is also available for checking against manufacturer documentation.
Limitation: The listed “50 ft venting distance” is not a substitute for verifying the water heater’s approved vent configuration. Confirm the precise part and installation requirements with the appliance documentation or a qualified professional.
Buying Guide: What to Check When a Water Heater Draft Hood Is Missing
Should you keep using the water heater?
No. If the appliance requires a draft hood and it is missing, do not operate it until the cause and correct repair have been established. A hood is part of the combustion-gas venting arrangement. Improper venting can allow exhaust to spill into the occupied space. Carbon monoxide cannot be seen or smelled, so the absence of an obvious odor does not make operation safe.
If anyone has symptoms such as headache, dizziness, nausea, weakness, or confusion and carbon monoxide exposure is possible, leave the building and contact emergency services. Use working carbon monoxide alarms as directed, but do not treat an alarm as a substitute for a repair or inspection.
How do you identify the correct replacement?
- Read the water heater’s manufacturer, model number, and serial number from its rating label.
- Check the manual or manufacturer parts information for the specified draft hood or connector part number.
- Confirm the required vent diameter and connection type. A 3-inch or 4-inch measurement alone is not enough to confirm fit.
- Compare the proposed part’s manufacturer, number, mounting arrangement, and listed dimensions with the appliance requirements.
- Ask a qualified professional to inspect the heater and vent system if the label, manual, or existing configuration is unclear.
Do not fabricate a hood, substitute a generic metal fitting, or rely on a seller’s product title as proof of compatibility. Do not modify the venting system to make a part fit. The complete installation must follow the water heater’s instructions and applicable local requirements.
How should the five options be compared?
The Rheem AS40665 and AS40665-A listings state 3-inch and 4-inch connection sizes. The AO Smith listing identifies a 3-inch-to-4-inch combination, while the Bradford White listing names a 3-inch connector. The generic Vent Hood listing does not provide a size in the supplied details. These differences make the products useful for initial comparison, but manufacturer and model compatibility should decide the purchase.
Choose a specifically identified manufacturer part when the water heater documentation calls for that part. Choose a product with stated dimensions only when those dimensions match the documented requirement. If the product information is incomplete, pause and verify rather than guessing. Installation and vent inspection should be handled by a qualified technician when required by the appliance instructions or local rules.
What should happen after installation?
Have the installer check that the hood and vent are correctly connected and that the venting system is suitable for the appliance. A replacement part does not resolve other possible problems, such as a damaged or obstructed vent. Follow the heater manufacturer’s operating instructions and keep carbon monoxide alarms installed and maintained according to their instructions.
Frequently Asked Questions
Can I run a gas water heater with the draft hood missing?
No. Stop using the heater until a qualified professional confirms the required part and repairs the venting arrangement.
Can I replace a missing draft hood with any 3-inch or 4-inch hood?
No. Vent diameter alone does not confirm compatibility. Match the water-heater model and manufacturer specifications, as well as the vent and mounting requirements.
Is a draft hood the same as a vent connector?
They are related parts of a venting system, but product names can vary. Check the appliance documentation to identify the specific component required rather than relying on a generic label.
How can I identify the right part if the original hood is gone?
Use the water heater’s rating label to locate its model information, then check the manual or manufacturer parts documentation. A qualified technician can verify the correct replacement and inspect the vent.
Does a carbon monoxide alarm make it safe to use the heater?
No. An alarm is an important safety device, but it does not correct missing or improper venting. Do not operate the heater until it has been inspected and repaired.