Yes, you can use a flex hose on a water heater, as long as it is rated for hot water and meets local plumbing codes to ensure safety and efficiency.
Flexible hoses offer a convenient solution for connecting water heaters, but are they safe and reliable? This guide explores the benefits, risks, and proper installation techniques for using flex hoses with water heaters.
Pros of Using Flex Hoses on Water Heaters
Flex hoses provide several advantages for water heater installations:
- Easy installation: Their flexibility allows for quick connections in tight spaces without complex pipe bending.
- Vibration absorption: They reduce water hammer effects better than rigid pipes.
- Earthquake resistance: In seismic zones, flex hoses can better accommodate movement.
- Maintenance friendly: Simplifies future water heater replacement or servicing.
Types of Approved Flex Hoses
Not all flex hoses are created equal. For water heater applications, only these types should be used:
| Type | Material | Max Temp | Max PSI |
|---|---|---|---|
| Stainless Steel Braided | 304 or 316 stainless steel | 180°F | 150 PSI |
| Corrugated Copper | Copper with polymer lining | 200°F | 125 PSI |
Cons and Safety Concerns
While convenient, flex hoses present some risks:
Potential Failure Points
- Rubber-lined hoses degrade faster from heat exposure
- Lower quality hoses may burst under pressure fluctuations
- Improper installation can lead to leaks at connections
According to PlumbingSupply.com, burst flex hoses cause thousands of dollars in water damage annually.
Manufacturer Recommendations
Most major water heater brands have specific guidelines:
- Rheem: Allows flex connectors but recommends rigid piping for optimal performance
- A.O. Smith: Approves stainless steel flex hoses up to 36″ in length
- Bradford White: Requires earthquake straps when using flex connectors
Always check your water heater’s manual before installation.
Proper Installation Guidelines
Follow these steps for safe flex hose installation:
- Shut off water supply and drain the heater
- Measure needed length (avoid stretching or kinking)
- Use two wrenches – one to hold fitting, one to tighten
- Install earthquake straps if required by code
- Check for leaks after pressurizing system
Critical Safety Checks
- Inspect hoses annually for bulges or corrosion
- Replace every 5 years as preventive maintenance
- Ensure proper support for water heater weight
When to Avoid Flex Hoses
Rigid piping may be better in these situations:
- Commercial applications with higher temperatures
- Systems with frequent pressure surges
- Areas with hard water that accelerates corrosion
- When local plumbing codes prohibit flex connections
For complex installations like parallel water heater setups, rigid piping often provides more reliable performance.
Maintenance and Inspection
Regular maintenance is crucial for flex hose longevity:
- Check for mineral buildup at connections
- Look for signs of rust or discoloration
- Feel for soft spots that indicate internal deterioration
- Listen for unusual noises that may signal flow restriction
The International Association of Plumbing and Mechanical Officials recommends replacing flex hoses at the first sign of wear.
