Yes, you can use a flexi hose on a water heater, but ensure it meets safety standards and is suitable for hot water applications to prevent leaks or damage.
Flexible hoses offer a convenient solution for water heater installations, but their use depends on local codes, material type, and manufacturer guidelines. This guide explores the pros, cons, and best practices for flexi hoses in water heater setups.
Flexible Hose Options for Water Heaters
Several flexible piping materials work with water heaters:
- Corrugated Stainless Steel (CSST): Durable, heat-resistant, and flexible. Often used in seismic zones.
- Braided Stainless Steel: Armored exterior with rubber interior. Common for short connections.
- PEX: Flexible plastic tubing that handles high temperatures. Requires proper fittings.
Why Choose Flexible Connections?
Flexible hoses simplify installation in tight spaces and allow for minor adjustments during water heater replacement. As noted in plumbing forums, they make future replacements easier since connection points rarely align perfectly between old and new units.
Key Considerations for Flexi Hose Use
1. Local Building Codes
Always check local regulations. Some areas restrict flexible hose use for gas lines or require specific materials. Wisconsin, for example, allows flex gas lines but may have special requirements.
2. Manufacturer Requirements
Water heater warranties often specify connection types. Using unapproved materials may void coverage. Consult the installation manual before proceeding.
3. Temperature and Pressure Ratings
Ensure the hose matches your system’s requirements:
| Material | Max Temperature | Pressure Rating |
|---|---|---|
| CSST | 400°F | 200+ PSI |
| Braided | 180°F | 150 PSI |
| PEX | 200°F | 160 PSI |
Installation Best Practices
Water Connections
For water lines:
- Use dielectric unions when connecting dissimilar metals
- Install isolation valves on both hot and cold lines
- Support pipes properly to avoid stress on connections
Consider adding a smart thermostat to optimize your water heater’s performance.
Gas Connections
For gas water heaters:
- Use only CSST or approved flex connectors
- Never use rubber hoses for gas
- Apply pipe dope rated for gas connections
Potential Issues with Flexi Hoses
Long-Term Durability
While flexible hoses simplify installation, they may have shorter lifespans than rigid piping. The RectorSeal study found CSST lasts 20+ years, but braided hoses typically need replacement every 5-10 years.
Flow Restrictions
Some plumbers report reduced flow with smaller diameter flex hoses. Ensure your hose matches the water heater’s inlet/outlet size (typically 3/4″ for residential units).
When to Avoid Flexible Connections
Rigid piping may be better when:
- Local codes prohibit flex connections
- Long pipe runs are needed (over 6 feet)
- High vibration environments exist
- Manufacturer requires rigid connections
For related heating solutions, explore electric fireplace options that provide supplemental warmth.
Professional Recommendations
Many plumbers suggest:
- Using flex lines for easier future replacements
- Adding a second shutoff valve on the hot water line
- Choosing CSST over braided hoses for longevity
- Following all local code requirements
As noted in plumbing forums, “Flex. Always. And add a valve on the hot side too, while you are at it. Makes changing out later so much easier.”
Maintenance Tips
Regularly inspect flex connections for:
- Signs of corrosion or mineral buildup
- Kinks or bends that restrict flow
- Leaks at connection points
- Proper support and positioning
Consider scheduling annual inspections with a qualified technician to ensure your water heater and connections remain in good condition.
