A Girard tankless RV water heater that stops producing hot water doesn’t necessarily have a failed water heater.
One of the first things I check with any RV on-demand water heater is water flow.
Tankless water heaters need adequate water moving through the system to operate properly. Low campground water pressure, a restrictive pressure regulator, dirty water filter, plugged faucet aerator, low-flow showerhead, or another plumbing restriction can sometimes look like a water-heater problem.
This guide focuses primarily on the Girard GSWH-2 tankless water heater and covers the things an RV owner can safely check before calling for service, including Girard error codes E0 through E9. (Manuals+)
Check These Things First
If your Girard tankless water heater isn’t producing hot water, start with the basics:
- Check the water flow.
- Make sure the propane supply is turned on and the tank isn’t empty.
- See whether other propane appliances operate normally.
- Make sure the water heater has adequate 12-volt DC power.
- Look at the Girard control panel for an error code.
- Check the exterior intake/exhaust area for an obvious obstruction.
- Reset the heater once and see whether the fault returns.
Don’t start replacing parts until you’ve ruled out the simple things.
Girard GSWH-2 Error Code Quick Reference
If the control panel displays an error code, start here. Detailed explanations for each code are farther down this guide. (Manuals+)
| Code | Meaning | Safe First Check |
|---|---|---|
| E0 | Outlet temperature probe fault | Reset once; service if it returns |
| E1 | Ignition failure/flame lost | Check propane supply |
| E2 | Flame lost during operation | Check propane; service if repeated |
| E3 | ECO/over-temperature safety fault | Allow heater to cool; service if repeated |
| E4 | Inlet temperature probe fault | Reset once; service if it returns |
| E5 | Blower motor fault | Check exterior vent; service if repeated |
| E6 | Water over-temperature | Check water flow and temperature setting |
| E7 | Linear gas valve fault | Service required |
| E8 | Air-pressure switch fault | Check exterior air/exhaust openings |
| E9 | Flame-sensor fault | Service required |
| En | 20-minute system timer | Turn hot water off and back on |
Important: Girard has produced more than one water-heater model. These codes are for the GSWH-2. Always verify your model number before using an error code to diagnose the heater.
The GSWH-2 also has a 20-minute operating timer. An En indication after approximately 20 minutes of continuous operation isn’t the same type of component failure as E0–E9; turning the hot-water faucet off and back on resets the operating cycle. (Manuals+)
Safety Stop
A Girard tankless water heater combines propane, electricity, combustion air and very hot water.
There are useful checks an RV owner can safely perform, but troubleshooting should stop when diagnosis requires opening the gas system, adjusting propane pressure, bypassing a safety device, disassembling the burner, or testing internal components unless you’re qualified to do so.
Stop using the heater and arrange for service if:
- You smell propane.
- You see scorching, melted wiring or evidence of fire.
- Water is leaking onto electrical components.
- The heater repeatedly overheats.
- The same safety-related error keeps returning.
- The repair requires opening or modifying the propane system.
Never bypass the ECO, flame sensor, air-pressure switch or another safety device to keep the heater running.
Check First: Does the RV Have Enough Water Flow?
This is one of my first checks when diagnosing an on-demand water heater.
Start by opening a hot-water faucet.
Is the flow strong and steady?
If the flow is weak, solve that problem before assuming the Girard heater has failed.
Check:
- Campground water pressure
- Water-pressure regulator
- Inline water filters
- Faucet aerators
- Showerhead
- Kinked hoses
- Partially closed plumbing valves
- RV pump operation
- Water-heater inlet/filter screen
- Air in the plumbing
Girard’s own troubleshooting information emphasizes adequate flow and checking strainers, filters and restrictions. Its service material uses approximately 0.8 GPM as the minimum flow needed to activate the unit, and its diagnostic procedure recommends switching to the fresh-water tank and onboard pump when measured faucet flow is below about 1 GPM. (Manuals+)
Try the RV Water Pump
If campground pressure seems poor, fill the fresh-water tank and operate the RV from its onboard water pump.
I’ve encountered on-demand water-heater complaints where the heater itself wasn’t the problem. There simply wasn’t enough water flow for the heater to operate correctly.
And if the Girard works properly on the RV pump but not on city water, you’ve learned something important.
Start looking at:
- Campground pressure
- Pressure regulator
- Water filter
- City-water inlet
- Hose restrictions
before blaming the heater.
Try Another Faucet
If one faucet has poor flow but another has good flow, look at the fixture.
A plugged faucet aerator or restricted showerhead can substantially reduce flow.
Check the Propane Supply
If water flow is good, move to the propane system.
Make sure:
- The propane tank contains fuel.
- The propane valve is open.
- Other propane appliances operate normally.
If the propane tank was recently filled, replaced or turned back on, there may be air in the propane lines.
One easy check is to see whether the RV range operates normally. Girard specifically recommends establishing propane flow through the system when diagnosing an E1 ignition fault. (Manuals+)
If other propane appliances also aren’t working, investigate the RV’s propane supply rather than assuming the Girard heater has failed.
Do not adjust propane regulator pressure yourself unless you’re qualified to work on RV propane systems.
Check the 12-Volt Power
The GSWH-2 depends on the RV’s 12-volt electrical system.
If the control panel is blank or the heater isn’t responding, check:
- Battery condition
- Battery disconnect
- 12-volt fuse panel
- Water-heater fuse
- Accessible wiring connections
Girard’s service documentation calls for more than 11 volts at the control board during certain diagnostic procedures. (Manuals+)
Low battery voltage can therefore create symptoms that look like an appliance problem.
If you’re not comfortable performing electrical testing, stop at the basic fuse and battery checks.
Girard GSWH-2 Error Codes
E0 — Outlet Temperature Probe Fault
E0 indicates that the controller has detected an open or short circuit involving the outlet-water-temperature probe or its wiring. (Mike’s Servers Library)
What you can safely do
Reset the heater once.
If E0 immediately returns, this is generally beyond basic owner troubleshooting.
The temperature probe, wiring or control system may need diagnosis.
Repeated E0: Book service.
E1 — Ignition Failure or Flame Lost During Ignition
E1 is one of the most useful Girard codes for an RV owner because there are several simple things to check before assuming a component has failed.
The heater attempted to establish a flame and couldn’t do so successfully. Girard lists lack of propane, low gas pressure and ignition-system problems among the possible causes. (Manuals+)
Start with propane
Check:
- Is there propane in the tank?
- Is the propane valve open?
- Does the RV stove operate?
- Was the propane supply recently disconnected or refilled?
If other propane appliances don’t work either, the Girard heater probably isn’t your first problem.
If everything else operates normally but E1 repeatedly returns, the heater may require professional diagnosis.
Potential internal causes include the igniter, connections, burner/igniter condition, gas valve or gas pressure.
Those aren’t where I’d recommend an inexperienced RV owner start taking things apart.
E2 — Flame Lost During Operation
E2 means flame sensing was interrupted while the heater was already operating. Girard indicates that the unit can enter lockout when this occurs. (Mike’s Servers Library)
This is different from a heater that never ignites.
If you hear the heater start and get hot water briefly before E2 appears, that’s useful diagnostic information.
Safely check:
- Propane level
- Whether other propane appliances work
- Whether the problem happens consistently
- Whether the propane supply was recently interrupted
If E2 repeatedly returns despite a good propane supply, professional diagnosis is appropriate.
E3 — ECO / Over-Temperature Safety Fault
E3 indicates that the Girard’s emergency cut-off (ECO) safety circuit has opened.
That’s an overheating-related safety condition and shouldn’t simply be ignored.
What you can do
Stop hot-water demand and allow the heater to cool.
Running cooler water through the unit can help cool the system, which is also part of Girard’s documented E3 troubleshooting. (Manuals+)
Once cooled, try the heater again.
If E3 returns, stop repeatedly resetting it.
Repeated overheating requires diagnosis.
E4 — Inlet Temperature Probe Fault
E4 indicates an electrical fault involving the inlet-water-temperature probe or its circuit. (Mike’s Servers Library)
There isn’t much useful owner-level troubleshooting here.
Reset the heater once.
If E4 returns, the sensor, wiring or controller may need to be tested.
E5 — Blower Motor Fault
E5 indicates that the control system isn’t receiving the expected blower-motor signal. Girard notes that the motor or its wiring can be involved. (Mike’s Servers Library)
What you can safely check
Before opening the heater, inspect the exterior vent/intake area.
Look for:
- Leaves
- Insect nests
- Mud-dauber nests
- Snow
- Ice
- Other obvious debris or obstruction
Don’t reach deeply into the heater or start disassembling the blower.
If everything visible is clear and E5 returns, the blower motor, wiring or control system needs further diagnosis.
E6 — Water Over-Temperature
E6 means the outlet-water temperature exceeded 140°F (60°C) for approximately three seconds. (Manuals+)
Before assuming there’s a failed temperature sensor, check the water-flow side.
Check:
- Is water flow strong?
- Is the water filter clean?
- Is the faucet aerator plugged?
- Is the showerhead restrictive?
- Is the pressure regulator reducing flow too much?
- Is there air in the plumbing?
- Is the temperature setting unnecessarily high?
Girard’s E6 troubleshooting specifically includes checking water flow and suggests using the onboard pump if measured faucet flow is below approximately 1 GPM. (Manuals+)
Try the onboard pump
If E6 occurs on campground water, try the fresh-water tank and RV pump.
If the problem disappears, investigate the campground supply and restrictions.
This is another reason water flow belongs near the top of the troubleshooting process.
E7 — Linear Valve Fault
E7 indicates an electrical fault involving the heater’s linear gas valve circuit. (Mike’s Servers Library)
This isn’t an owner-level repair.
Reset the heater once.
If E7 returns, arrange for professional service.
Do not bypass or modify the gas valve.
E8 — Air-Pressure Switch Fault
E8 relates to the air-pressure switch and combustion-air/exhaust system.
Girard notes that the condition can be associated with a blower/motor problem or a blockage in the air supply or exhaust. (Mike’s Servers Library)
Check outside
With the heater off, inspect the exterior intake/exhaust area.
Look for:
- Debris
- Insect nests
- Snow or ice
- Leaves
- Anything physically blocking airflow
If the vent is clear but E8 returns, further internal diagnosis is required.
E9 — Flame Sensor Fault
E9 means the controller detects a flame signal before ignition should occur. Girard describes this as a flame-sensor short condition. (Mike’s Servers Library)
There isn’t a meaningful external repair for an RV owner to perform.
Reset the unit once.
If E9 returns, book service.
En — 20-Minute System Timer
This one can look more alarming than it actually is.
The Girard GSWH-2 has a system timer that stops burner operation after approximately 20 minutes of continuous operation. The display can show En when this happens. (Manuals+)
Turn the hot-water faucet off and then back on to begin another operating cycle.
If your “problem” consistently occurs at almost exactly 20 minutes, the timer may be what you’re seeing rather than a random shutdown.
Girard Water Heater Has Good Flow but Won’t Ignite
If you’ve established good water flow but don’t get ignition, look at the control panel.
E1 appears
Start with propane.
Make sure:
- The tank isn’t empty.
- The propane valve is open.
- The stove works.
- Propane has had a chance to purge through the system after a tank change or refill.
If propane is definitely available and E1 continues, further diagnosis is needed.
No error code
Check:
- 12-volt power
- Controller operation
- Water flow
- Water-heater fuse
If all four are good and the heater doesn’t attempt to operate, it’s probably time for deeper diagnosis.
Girard Water Heater Works on the Pump but Not City Water
This is a very useful diagnostic clue.
If the Girard works normally using the RV’s onboard pump but not when connected to campground water, look at the water supply.
Check:
- Campground water pressure
- Pressure regulator
- Inline water filter
- Hose
- City-water connection
- Plumbing restrictions
Don’t replace the water heater because it doesn’t like a poor water supply.
Girard Water Heater Gets Hot, Then Cold
Temperature fluctuations frequently point toward changing water flow.
Check whether:
- Someone opens another faucet.
- The toilet is flushed.
- Campground pressure fluctuates.
- The showerhead restricts flow.
- A filter is dirty.
- You’re mixing a large amount of cold water with the hot.
Try setting the heater closer to your desired shower temperature
This is a trick I like with on-demand systems.
Instead of setting the water heater very hot and then adding a lot of cold water at the shower, try setting the controller closer to the actual temperature you find comfortable.
Then use mostly hot water.
This maintains stronger flow through the hot-water side and can help an on-demand heater operate more consistently.
Girard Water Heater Isn’t Hot Enough
Start with the controller temperature setting.
Then check water flow and consider the temperature of the incoming water.
Very cold incoming water requires the heater to produce a much larger temperature rise.
Also verify:
- Adequate propane supply
- Good 12-volt power
- Steady water flow
- Clean filters and aerators
If the display indicates the correct temperature but the actual water remains substantially colder, the heater may need professional diagnosis.
Girard Water Heater Shuts Off After 20 Minutes
If it works perfectly and then shuts down at roughly the same time every time, look for En on the display.
The GSWH-2’s built-in system timer stops burner operation after approximately 20 minutes. (Manuals+)
Turn the hot-water faucet off and back on to restart the operating cycle.
That’s very different from an E1, E2 or overheating shutdown.
Most Common Things to Check Before Calling for Service
If I were approaching a Girard tankless water heater with no hot water, my basic diagnostic order would be:
1. Water flow
Is there strong, steady water flow?
2. Propane
Is propane available, and do other gas appliances work?
3. 12-volt power
Does the controller have power?
4. Error code
What is the heater actually telling you?
5. Exterior vent
Is there an obvious obstruction?
Those five checks can tell you quite a bit before any part of the heater needs to be opened.
When to Book Service
It’s time to have the Girard professionally diagnosed when:
- E0 repeatedly returns.
- E1 continues despite a known-good propane supply.
- E2 repeatedly occurs during operation.
- E3 repeatedly indicates an ECO/over-temperature condition.
- E4 returns after resetting.
- E5 remains after basic exterior checks.
- E6 continues despite good water flow and reasonable temperature settings.
- E7 appears repeatedly.
- E8 remains after confirming the exterior vent isn’t obstructed.
- E9 returns.
- The heater has adequate water flow, propane and 12-volt power but still doesn’t operate.
- You smell propane.
- You see damaged wiring, scorching or overheating.
- The repair requires opening the propane system.
Service Call Prep
Before contacting an RV technician, write down:
- Girard model number
- Serial number
- Error code
- Temperature setting
- Whether you’re using city water or the onboard pump
- Whether other propane appliances work
- Whether the problem occurs at every faucet
- Whether the burner attempts to ignite
- Whether hot water appears briefly before the error
- Whether the problem is intermittent
- Whether switching to the RV pump changes the problem
That last piece of information can be particularly helpful when separating a water-supply problem from a heater problem.
FAQ
Why won’t my Girard tankless water heater ignite?
Start with water flow and propane supply. Make sure the heater has adequate 12-volt power as well. If the GSWH-2 displays E1 despite good water flow and a known-good propane supply, further ignition-system diagnosis may be necessary.
What does E1 mean on a Girard tankless water heater?
E1 indicates an ignition failure or loss of flame during the ignition process. Check that the RV has propane and that other propane appliances operate before assuming the water heater has failed. (Mike’s Servers Library)
Can low water pressure cause problems with a Girard tankless water heater?
Yes. The GSWH-2 requires adequate water flow to activate and operate correctly. Restrictions from filters, regulators, aerators, showerheads or campground supply can cause problems. (Manuals+)
Why does my Girard work with the RV pump but not city water?
That strongly suggests checking the campground water supply, pressure regulator, filter, hose and city-water inlet. If the onboard pump provides sufficient flow and the campground connection doesn’t, the heater itself may be fine.
What does E6 mean on a Girard water heater?
E6 indicates an over-temperature condition where outlet water exceeded approximately 140°F (60°C). Check the temperature setting and water flow before assuming a component has failed. (Manuals+)
What does En mean on a Girard water heater?
En indicates the GSWH-2’s approximately 20-minute system timer has been reached. Turn the hot-water faucet off and back on to start another operating cycle. (Manuals+)
Why does my Girard shower go hot and cold?
Changing water flow is one possible cause. Check campground pressure, water filters, showerhead restrictions and whether other fixtures are being used. Try setting the water heater closer to your preferred shower temperature so less cold water needs to be mixed in.
Should I keep resetting a Girard water heater with an error code?
No. One reset can determine whether a fault was temporary. If the same error repeatedly returns, use the code to identify the next diagnostic direction or arrange for service.
When a Girard tankless RV water heater isn’t working, start with water flow before replacing anything.
Then verify propane, 12-volt power, the control-panel error code and the exterior vent.
If the heater works normally from the RV’s onboard pump but not campground water, investigate the incoming water supply and restrictions. If a code points toward an internal sensor, gas valve, blower, flame sensor or safety circuit, that’s where basic DIY troubleshooting should end.
The goal isn’t to take the entire water heater apart.
It’s to determine which system is actually causing the problem before you start replacing parts.
Related Articles:
- RV On-Demand Water Heaters: How They Work and What Owners Should Know
- Furrion Tankless RV Water Heater Troubleshooting: A Step-by-Step Guide
- Water Heater Doesn’t Work On Propane
Written by Dan Harvickson (Founder of Last Mountain Tech) RV Specialist