Protecting an outdoor tankless water heater is crucial for ensuring it functions properly and lasts a long time. Outdoor tankless water heaters face exposure to the elements, which can cause a variety of issues over time if not properly addressed. Fortunately, with some simple preventative measures, you can keep your outdoor tankless unit running optimally for years to come.
Selecting the Right Location
Choosing the optimal location is the first step in protecting an outdoor tankless water heater. Here are some key factors to consider when selecting where to install the unit:
Shelter from Weather
Situate the tankless heater in an area shielded from direct sun, rain, snow, and other extreme weather. Overhanging eaves, awnings, or an adjacent structure can help block exposure. Avoid low areas where puddles may form.
Good Ventilation
Proper airflow is vital so the unit can sufficiently exhaust combustion gases. Allow at least 18-24 inches clearance on all sides, and do not enclose the heater fully on more than two sides.
Firm, Level Surface
Install the heater on a solid, even base like a concrete pad. This prevents settling and movement that could strain connections. Make sure the area drains well to prevent water pooling under the unit.
Close to Water Lines
Position the tankless water heater as near as possible to the hot water points of use to minimize heat loss in the pipes. Long hot water lines waste energy and water.
Convenient Gas Supply
Connecting to an existing gas line is ideal. If that is not feasible, make sure tank placement allows for a short gas line that meets code requirements.
Accessible Location
Do not block access to the heater for maintenance and repairs. Also consider potential leaks and ensure water from a broken line would drain away from the home.
Insulating the Water Heater
Insulation is key for outdoor tankless water heaters to maintain heat and energy efficiency.
Insulate Water Pipes
Use foam pipe insulation around both the cold inlet and hot water outlet pipes connected to the heater. This minimizes heat loss so more hot water reaches fixtures.
Install a Water Heater Jacket
An insulated jacket custom-fit for the specific model wraps around the tankless unit. It protects components from temperature extremes and keeps heat focused inside.
Use Heat Tape
Applying self-regulating heat tape along the water pipes prevents freezing in cold climates. Be sure to use exterior-rated tape and install per instructions.
Insulate Nearby Valves
Foam valve covers slipped over shut-off valves, unions, and other fittings prevent heat radiating through contact points.
Weatherproof Enclosures
For extreme climates, a weatherproof enclosure provides additional insulation and protection. Make sure venting and access are still properly accommodated.
Safeguarding Connections
Properly protecting the water, gas, electrical, and venting connections safeguards operation.
Use Gas Flex Lines
Flexible gas lines absorb vibrations from the unit that rigid pipes transfer, preventing leaks. Ensure flex lines are code approved for exterior use.
Heat Tape Pipe Fittings
In cold regions, apply UL-listed heat tape to pipe fittings like elbows, tees, and valves where condensation can form and freeze.
Seal Threads and Joints
Use gas-rated tape or thread sealant on all gas line connections. For water pipes, use mechanical joints instead of threaded fittings when possible for a more dependable seal.
Weatherproof Electrical
Use exterior-rated wiring and connections approved for wet locations. Heat shrink wire nuts and seal penetrations into the electrical box.
Venting Collars
Collars slipped over the intake and exhaust vent terminations prevent rain and debris from entering. Use vent screens to stop animals and insects.
Anchor Well
Securely anchor water and gas lines to reduce strain on fittings. Use wall straps or plumbers tape for support. Vibration pads cushion the unit.
Maintaining the Tankless Water Heater
Routine maintenance is essential for trouble-free operation and longevity of an outdoor tankless water heater.
Inspect Annually
Check connections, venting, electrical components, and all exterior features for any needed repairs at least once a year. Address minor issues before they become major.
Flush Per Manufacturer
Mineral scale buildup inside the heat exchanger diminishes efficiency. Flushing removes deposits. Follow the manufacturer’s directions for proper procedure and frequency.
Test Pressure Relief
Manually operate the pressure relief valve annually to ensure it still functions properly. Replace it if needed. This prevents dangerous pressure buildups.
Check Burner Flame
Inspect the burner flame periodically to verify it is blue and steady, not flickering or burning orange. Have a technician adjust it if abnormal.
Use Filtered Water
Filtered water prevents scale buildup and debris that can clog components. Install an in-line filter if water quality is a concern.
Keep Exterior Clean
Use a soft brush and mild soap to gently wash dirt and debris off the outside casing to prevent corrosion and rust over time.
Drain in Winter
In extremely cold climates, drain the heater for winter if shutting it fully down. This prevents residual water from freezing and damaging the heat exchanger.
Update Vent Screens
Replace old vent termination screens so they remain effective at blocking animals and debris. Use corrosion resistant 316 grade stainless steel.
Troubleshooting Common Outdoor Tankless Water Heater Issues
Even well-maintained outdoor tankless heaters can still experience occasional problems. Knowing how to troubleshoot key issues provides the ability to quickly resolve them.
Unit Fails to Ignite
- Check the gas supply valve is fully open and supply lines are purged of trapped air
- Verify electrical connections are intact and breaker is on
- Inspect burner assembly for obstructions like spider webs
- Reset unit and try lighting again after a cooldown period
Irregular Burner Flame
- Remove debris or obstructions around burner
- Have gas pressure checked by a technician
- May need burner adjustment or servicing if flame is uneven or unstable
Low Hot Water Pressure
- Confirm water filters are not clogged
- Check for kinks or blockages in pipes
- Try increasing temperature setting
- Scale buildup inside heater reduces flow – flush heat exchanger
Not Heating Water Sufficiently
- Verify gas supply is still adequately sized for unit
- Clean intake air screen if blocked
- Replace flame rod sensor if cracked or corroded
- Have heat exchanger checked – may need de-scaling
High Temperature Fluctuations
- Examine all fittings and connections for water leaks
- Inspect heat exchanger coils for mineral buildup
- Verify gas pressure remains steady
- Clean or replace water flow sensor
Overheating/Tripping Safety Devices
- Check for adequate clearances around unit
- Clean air intake and exhaust terminations
- Ensure water chemistry meets standards
- Replace damaged gaskets or seals
Water Leaking
- Tighten any loose pipe fittings
- Replace cracked or worn gaskets and fittings
- Check heat exchanger, valves, and lines for cracks
- Ensure pressure relief valve isn’t stuck open
Outdoor Tankless Water Heater Safety Tips
Safety should always be the top priority when operating and maintaining an outdoor tankless unit. Follow these important safety measures:
- Turn off gas and water supply before any work
- Test for gas leaks annually with soapy water
- Relieve pressure before disconnecting pipes
- Allow heater to fully cool before maintenance
- Verify electrical ground is intact
- Never modify the heater or components
- Keep vent terminations clear of snow, leaves, etc
- Install CO detectors and check batteries
- Review manual for all warnings
- Ensure clearances from combustibles
- Have heater serviced by a qualified technician
Conclusion
Installing an outdoor tankless water heater requires taking important protective measures to maximize performance and lifespan. Choosing the right location, insulating properly, safeguarding connections, maintaining the system, troubleshooting issues, and following essential safety practices together help safeguard these units from outdoor elements. With proper care, an outdoor tankless heater can provide endless hot water for many years.
Frequently Asked Questions About Protecting Outdoor Tankless Water Heaters
Can outdoor tankless water heaters be left outside in winter?
Yes, outdoor tankless water heaters can withstand winter temperatures as low as -30°F when properly installed and protected. Insulating pipes, using heat tape, and maintaining clearances are key. Draining the unit for winter is recommended in extreme climates.
How often should I maintain my outdoor tankless water heater?
General maintenance like inspecting connections, testing pressure relief valves, replacing filters, and flushing the heat exchanger should be performed annually. More frequent maintenance may be required in hard water areas.
What causes flow problems with outdoor tankless heaters?
Low hot water flow is most often caused by mineral scale buildup inside the heat exchanger. Annual flushing removes deposits. Clogged inlet filters, kinked hoses, and failing water flow sensors can also restrict flow.
Why does my outdoor heater shut down during hot showers?
Frequent shutdowns during peak use are typically caused by under-sized gas lines leading to the unit. A technician can determine if your gas line meets the heater’s BTU and volume demands.
How do I protect my outdoor heater’s electrical connections?
Use only exterior-rated wiring and connections. Seal all penetrations into the electrical box. Heat shrink wire nuts help prevent moisture infiltration. A weatherproof receptacle cover adds further protection.
What temperature should I set my outdoor tankless water heater to?
Start with a 120°F setting to prevent scalding risks. Increase if more hot water capacity is needed for showers or other uses. Lower to 100°F if concerned about wasting energy.
Can I enclose my outdoor tankless heater with siding?
You should not fully enclose the heater on more than two sides, as it needs unobstructed airflow for combustion and ventilation. Use siding with spacers to provide the minimum clearances.
How often should I test the pressure relief valve?
Safety experts recommend manually operating the pressure relief valve at least once a year to ensure it still functions properly and will open if dangerous pressure builds up.
What temperature range can outdoor tankless heaters handle?
Most standard models can operate in temperatures ranging from -30°F to 150°F. Special freeze protection components are available for extreme cold climates. High-temperature models go up to 180°F.