Bradford White AeroTherm Error Codes: F11, F20 and 94
By Ray Bennett · Updated 23 October 2026 · 10 min read · Checked against the maker’s manual 
Bradford White AeroTherm heat pump water heaters show two kinds of code. The AeroTherm Series (RE2H...-1NCTT) shows F codes: F11 is a dry tank, F14 a dirty filter and F20 a blocked condensate drain port. The Series G2 (RE2HP) shows numbers: 11 is a dirty filter and 94 a blocked condensate drain port. The AeroTherm Series manual says never to replace a part based solely on a fault code.
Bradford White AeroTherm error codes come in two styles, depending on which AeroTherm you have. The AeroTherm Series heat pump water heater shows an F code, such as F11 or F20. The AeroTherm Series G2 shows a fault code number, such as 6 or 94.
Bradford White puts a note above the table in its AeroTherm Series manual: a fault code only helps identify parts that need testing, and the control can generate a false fault if the right conditions exist. Never replace a part based solely on a fault code. Everything below comes from Bradford White’s own installation and operation manuals and its AeroTherm quick service guide.
Before you start
What to carry: a torch, a pen, and paper for the code and the model number.
Gas or electric? Electric. An AeroTherm heats water with a heat pump and has electric heating elements as a backup. Both manuals say 240 VAC or 208 VAC must be applied across its L1 and L2 wires.
Which AeroTherm is it? Look for it on the rating label on the front of the water heater, or in the back of the manual, where Bradford White asks you to write the model and serial number. RE2H50S10-1NCTT, RE2H65T10-1NCTT and RE2H80T10-1NCTT are the AeroTherm Series heat pump, and the same numbers ending in -CON have Bradford White Connect. RE2HP5010, RE2HP6510 and RE2HP8010 are the Series G2. Older models ending in -1NCWT, from before December 2023, have their own documents on Bradford White’s archive list.
Renting? Send the code, the model and whether you still have hot water to whoever arranges repairs.
What Bradford White says: if the water heater has been subjected to flood, fire or physical damage, turn off the power and water to it, and do not run it again until qualified service personnel have checked it thoroughly. Its manuals also say to turn off the power if it has been subjected to overheating. On a Series G2, code 7 is the tank has overheated.
Been under water? Do not use it if any part has been submerged. Bradford White says the plumbing professional who installed it should be contacted to inspect it and replace any part of the control system that was submerged.
Water first, then power. Do not turn it on unless it is filled with water, and not with the cold water supply shut off valve closed. Shut off the power before draining any water, to avoid the risk of shock.
Which codes your AeroTherm shows
The AeroTherm Series has a MODE button, UP and DOWN arrows, an ENTER key and a FILTER button with a red light above it. Its codes are F and a number, F and a letter, or the words bAd linE.
The Series G2 has a menu, arrow keys, and SELECT and BACK buttons. Its manual and quick service guide list numbered codes between 1 and 99.
The AeroTherm Series F codes
Bradford White’s table gives the number of times a fault has to happen before its code is displayed: once for F11, F12 and F13, five times for the dirty filter, and ten times for most of the rest. Selected rows:
| Code | What Bradford White’s table says |
|---|---|
| F11 | Dry tank fault: not enough water in the tank for water heater operation |
| bAd linE / F12 | The voltage is too low at power up (below 155 VAC) |
| F13 | Stuck key: a button on the front panel is stuck down |
| Dirty Filter (F14) | Filter is too dirty to enable proper function of the water heater |
| F20 | Condensate drain port blocked |
| F3 / F4 | Compressor failure / fan failure |
| F9 / F10 | Lower / upper heating element failure |
| F16 | Anode depleted (on some models) |
| F19 | Low line voltage |
| FC | Checks the evaporator is free of frost |
| FI | Early indication of a refrigerant leak (on some models) |
| F2 / F24 | Tank temperature sensor failure (T2 / T1) |
F13 clears by itself when the stuck button comes free, and the other buttons work normally meanwhile. When the room is outside the heat pump’s range, which this manual gives as above 35°F and below 120°F, it switches to Electric/Standard Mode for that heating cycle only, and no code is shown.
The Series G2 numbered codes
Selected rows from the G2 manual and quick service guide:
| Code | What Bradford White’s table says |
|---|---|
| 3 / 4 | Lower / upper element fault |
| 5 | Control fault: a microcontroller or relay fault in the main control board |
| 6 | Supply voltage fault: the voltage is too low at power up (below 155 VAC) |
| 7 | Tank over temp: the tank has overheated |
| 8 / 9 | Fan fault / compressor fault |
| 10 | Superheat fault: the system may be too low in refrigerant |
| 11 | Airflow restriction: the filter is too dirty |
| 16 | Ambient temp hi/lo: too hot or too cold to run the compressor |
| 18 | Water leak detected |
| 94 | Condensate fault: condensate drain port blocked |
| 93, 95 to 98 | Hard faults (element, EEV, superheat, compressor, fan): operation cannot continue |
| 1 / 99 | Lower (T1) / upper (T2) tank temperature sensor fault |
Two pages of the same G2 manual use other numbers. Its installation page calls a tank that is not full Fault Code 10, and its maintenance page calls a clogged condensate drain Error Code 16. Both are covered in the checks below.
What you can check
Write down the code and the model
Find the code in the table for your model. Bradford White’s AeroTherm Series manual says to contact a certified technician to assess and repair the heater based on the fault codes, and not to replace a part on a code alone, so the code and model number are what the technician needs.
Just filled, drained or installed? F11, or 10 on a G2
Bradford White says F11 appears if the unit is powered on without a full tank, and the G2 installation page says the same of Fault Code 10. In both cases: turn the power off, finish filling the tank with water, then turn the power back on. To fill it, Bradford White says to close the drain valve, open the cold water supply shut-off valve and open several hot water faucets to let the air out. The tank is full when a steady stream of water flows from the faucets; then close them.
Bradford White also says this dry tank check is an aid for the installer, not the primary control against an empty tank, and that power should never be applied until the tank is filled and all air has been purged. If the tank was already full and a G2 shows 10, the table’s meaning applies, a superheat fault, and that is a technician’s job.
Filter light and alarm, F14 or 11: clean the filter
On the AeroTherm Series, the red light above the FILTER button comes on and an alarm sounds. On the G2, a fault code tells you the filter needs cleaning. Bradford White’s steps:
- Leave the power on.
- Take the filter out of the top of the unit (on the AeroTherm Series, squeeze the two tabs and lift).
- Vacuum it, wipe it with a damp cloth or rinse it with warm water, and let it dry.
- Push it back into place.
- On the AeroTherm Series, press and hold the FILTER button for 5 seconds to reset the alarm. The G2 manual says to reset the alarm.
If the filter gets too dirty, the unit switches to Electric (Only) Mode and the energy savings are lost. If the alarm returns within a few days of cleaning, the AeroTherm Series manual says it may be a sign of a refrigerant leak, and both manuals say a service technician needs to look at it.
Alarm with F20 or 94: clear the condensate drain
Bradford White says that if the main condensate drain is clogged, the heat pump stops, the code shows and an alarm sounds. Press any button to silence the alarm, then clear the drain by removing any drain lines and connections and clearing the debris. Reattach them and let the heater run.
Meanwhile it keeps making hot water with its backup heating elements, and the heat pump runs again once the drain is clear. On a G2 showing 16, check the drain first, since its maintenance page gives 16 for a clogged drain.
Heat pump not running, or 16 on a G2: the room temperature
The AeroTherm Series heat pump runs between 35°F and 120°F around the heater, and the G2 between 37°F and 120°F. Outside that range, Bradford White says it heats with the electric elements instead to protect the unit, and returns to normal when conditions permit. Very low voltage does the same.
On a G2 the table gives 16 as too hot or too cold to run the compressor. If the room is well inside the range and the drain is clear, call a technician.
bAd linE, F12, F19 or 6: the power supply
These are low voltage codes. Bradford White says bAd linE at installation means incorrect wiring. The fix is to turn the power off, correct the wiring, and turn it back on, which is work for the electrician or installer.
Its manuals add that utility power management devices, or timer switches that drop the supply from 240 VAC to 120 VAC at busy times, must be removed from the heater’s circuit. Devices that cut the power to 0 VAC for a period are acceptable. If your utility fitted a load control switch, mention it.
The codes that need a technician
Compressor, fan, heating element, sensor, control board and EEV codes are not owner checks. Bradford White’s table gives FI, on some AeroTherm Series models, as an early indication of a refrigerant leak, and 10 on a G2 as a sign the system may be too low in refrigerant.
On the G2, 18 is water leak detected. Look for water at the drain valve, the temperature and pressure relief valve and the hot and cold water connections, the places Bradford White’s filling steps name for leaks, and if the heater has been flooded, follow the warning at the top of this page.
F16, on some models, is anode depleted: the anode light comes on and an alarm sounds. Bradford White says checking the anode needs the power and cold water supply turned off and should be done by a qualified servicer or plumber, because of the shock hazard and the risk of leaks.
What each one takes
| What you see | What the work involves |
|---|---|
| F11, or 10 right after filling | Power off, fill the tank, power on |
| Filter light, F14 or 11 | Cleaning the filter and resetting the alarm |
| F20 or 94 | Clearing the condensate drain lines |
| Heat pump off in a cold or hot room, or 16 | It returns to normal when the room is back in range; on a G2, check the drain first |
| bAd linE, F12, F19 or 6 | An electrician for the wiring or supply |
| Compressor, fan, element, sensor or refrigerant codes | A certified technician |
| Flood, fire or overheating | Power off; after a flood or fire, water off too and a check by qualified service personnel |
Questions people ask
What does F11 mean on a Bradford White AeroTherm?
A dry tank fault: there is not enough water in the tank. Bradford White says to turn the power off, finish filling the tank, then turn the power back on.
What does error 94 mean on a Bradford White AeroTherm G2?
The condensate drain port is blocked. Silence the alarm, clear the drain lines and connections, and reattach them. It heats with the electric elements until the drain is clear.
How do I reset the filter light on an AeroTherm?
Clean and refit the filter with the power on, then on the AeroTherm Series press and hold the FILTER button for 5 seconds. If it comes back within a few days, call a technician.
Why is my AeroTherm only heating with the elements?
A dirty filter, a blocked condensate drain, a room outside the heat pump’s temperature range or very low voltage all make it heat with the elements. Check the filter and the drain first.
Are these the same codes as my Bradford White gas water heater?
No. A Bradford White gas tank heater has its own codes, covered in Bradford White water heater codes.
The other heat pump water heater guides: heat pump water heater not heating, A.O. Smith heat pump water heater codes and Rheem heat pump water heater codes.
Sources: Bradford White AeroTherm Series heat pump water heater installation and operation manual 238-52169-00 (RE2H50S, RE2H65T, RE2H80T), AeroTherm Series G2 hybrid electric heat pump water heater manual 238-55123-00, AeroTherm quick service guide 238-55219-00, and Bradford White's residential heat pump documentation list
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