Plumbers or licensed HVAC technicians typically install tankless water heaters, as they require specific knowledge of plumbing and electrical systems to ensure safe and efficient operation.
Tankless water heaters provide endless hot water while saving energy. But proper installation requires specialized skills. This guide explains who can install them, what’s involved, and how to choose the right pro.
Licensed Professionals for Tankless Water Heater Installation
Only qualified technicians should install tankless water heaters. The two main types of professionals are:
Licensed Plumbers
Plumbers handle water line connections, gas piping, and venting requirements. They ensure proper water flow and pressure for tankless units. Many states require plumbers to hold specific licenses for gas appliance installations.
HVAC Contractors
HVAC pros specialize in combustion systems, venting, and gas line sizing. They understand the high BTU requirements of tankless heaters. Some areas require HVAC certification for gas appliance installations.
Installation Process Overview
Professional installation typically includes these key steps:
| Step | Description | Professional Needed |
|---|---|---|
| Gas Line Upgrade | Most tankless units need 3/4″ or 1″ gas lines | Plumber or HVAC |
| Venting Installation | Direct vent or power vent systems | HVAC specialist |
| Water Connections | Proper sizing and isolation valves | Plumber |
| Electrical Hookup | For ignition and controls | Electrician (if required) |
Why Professional Installation Matters
DIY installation often leads to problems:
- Gas line issues: Undersized pipes cause poor performance
- Venting mistakes: Can lead to dangerous carbon monoxide leaks
- Water flow problems: Improper sizing causes temperature fluctuations
- Voided warranties: Most manufacturers require professional installation
According to Home Depot’s installation guide, tankless units may need 90k to 130k BTU/H gas input – much higher than traditional tanks.
Choosing the Right Installer
Follow these tips when selecting a professional:
- Verify state licensing and insurance
- Check manufacturer certifications (Rinnai, Navien, etc.)
- Ask about experience with your specific model
- Get multiple quotes (average cost is $1,500-$3,500)
- Request references from recent jobs
Special Considerations
Some situations require extra expertise:
- Whole-home vs point-of-use: Larger units need more capacity planning
- Recirculation systems: Adds complexity to the installation
- Hard water areas: May need special descaling solutions
- Cold climates: Requires freeze protection measures
Cost Factors
Installation costs vary based on:
- Unit type (gas vs electric)
- Home size and hot water demand
- Needed upgrades (gas lines, electrical, venting)
- Local labor rates
- Permit requirements
For comparison, see our guide on electric vs gas water heater installation differences.
Maintenance After Installation
Professional installers should explain:
- Annual descaling procedures
- Filter cleaning schedule
- Winterization for outdoor units
- Error code troubleshooting
Proper maintenance extends the life of your tankless system and maintains efficiency.
