Rheem Heat Pump Water Heater Codes: A008, A108, T131

By Ray Bennett · Updated 2 October 2026 · 6 min read · Checked against the maker’s manual

Rheem Heat Pump Water Heater Codes: A008, A108, T131

Short answer

A Rheem hybrid water heater beeps and shows an alarm code. Many codes mean the heat pump has stopped and the heater has fallen back to its electric elements, which still makes hot water but costs more. A008 means the tank is not full, A107 water on the floor, A108 a blocked condensate line and T131 a dirty air filter.

A Rheem heat pump water heater, the hybrid kind that heats with a small heat pump on top and electric elements as backup, beeps and shows an alarm code when something is wrong. Some codes only switch it to the elements, some stop it heating altogether, and a few are reminders.

Everything on this page comes from Rheem’s own use and care manual AP23657 for its electric residential hybrid water heaters. Rheem’s own advice is to review its alarm charts before calling for service, because some of these you can put right yourself.

Before you start

What to carry: a torch, a pen and some mild detergent for the filter. Ten minutes to read the code, twenty for the filter.

Gas or electric? Electric. The heat pump does most of the work and the two elements are the backup.

Read every alarm, not just one. Rheem’s steps: press Next until “Current Alarm” shows, then press the down arrow to scroll through the active alarms.

Notice whether you still have hot water. It tells you which kind of alarm you have, before you even look it up.

What Rheem leaves to a technician. A200 means the high limit, the ECO, has tripped. Rheem’s display says to call tech service, and the heater stays disabled until it is fixed.

The sealed system is not repaired. For the compressor codes, Rheem says to look for oily residue that marks a refrigerant leak, and that if the compressor is not working or is leaking, the unit is replaced because it does not service sealed system parts. Turn the power off at the breaker before any cover comes off.

What an alarm does to your hot water

Rheem's table says, for each code, whether the heater falls back to its elements, disables itself, or is only reminding you.

Check 1Free, two minutes

Sort the alarm first

Falls back to the elements. Rheem’s table says the compressor codes, the heat pump sensor codes, low airflow and a blocked condensate line all switch the heating to the elements. You get hot water, but the bill rises until it is fixed.

Heater disabled. A dry tank, a tank sensor, an element fault, a tripped ECO or a controller fault stop it heating at all.

Reminders. T131 asks for the filter to be cleaned, and T132 says the heater cannot keep up with demand.

Every alarm code in Rheem’s table

Code	What Rheem says it means	What happens
A004	Compressor shutdown, discharge to suction trip	Runs on the elements
A005, T005	Compressor shutdown, discharge temperature high; low airflow	Runs on the elements
A006, T006	Suction temperature too low	Runs on the elements
A008	Dry fire condition, not enough water in the tank	Heater disabled
A009, T009	Compressor wiring may be faulty	Runs on the elements
A101, A102, A105, A106	Suction, ambient, evaporator or discharge sensor failure	Runs on the elements
A103, A104	Lower or upper tank temperature sensor failure	Heater disabled
A107	Water detected on the floor, check for leaks	Alarm
A108	Condensate blocked, unclog the line	Runs on the elements
A120 to A123	Shut-off valve cannot close or open, or is not installed	Alarm
A125, A126	Lower or upper element error, or relay stuck closed	Heater disabled
A127	Element wiring routed wrong	Heater disabled
A128, A129	Lower or upper element relay will not close	Heater disabled
A130	Unit off and the air is freezing, enable the unit	Freeze warning
T131	Clean filter reminder	Reminder
T132	Heater having difficulty satisfying demand	Reminder
A200	High water temperature, the ECO has tripped	Heater disabled
T300	Water leak sensor not installed	Alarm
A502, A503	Time clock not programmed or not advancing	Heater disabled
T504	Wi-Fi chip communication error	Controller
A900 to A905, T901	Controller fault, call tech service	Service
A906	Power board temperature protection, controller too hot	Service

The checks that are yours

Rheem's four steps for the T131 filter reminder. A clean filter also keeps the heat pump from tripping on low airflow.

Check 2Free, twenty minutes

Work Rheem's owner fixes

T131: the air filter. Set the mode to Electric or OFF, take the filter out, wash it with a mild detergent, let it dry, refit it and set your mode again.

T005, low airflow. Rheem’s steps for the compressor shutdowns include confirming the filter screen is clean and the fan runs while the compressor is on. A clean filter is the free half of that.

A008: the tank is not full. Rheem says to fill the tank and purge the air by running a hot water faucet. It calls this generally an installation issue, and says to purge again if the code stays.

A107: water on the floor. Look for an obvious leak first: where a water heater leak is really coming from. Rheem says holding the Clear Alarm button for 5 seconds overrides the alarm for 24 hours while you find out.

A108: the condensate line. Rheem’s check is that the condensate line is clear and the pan is not full, and where the line drains to. Clear the outside end if it is blocked.

T132: it cannot keep up. Rheem says to check for open faucets and water leaks, and that if there are none the heater may be too small for the house.

A130: freeze warning. The unit is off and the air around it is below freezing. Select a mode to turn it back on.

When it needs a technician

Check 3Parts to a new heater

Know when to stop

A004 to A006, and A009. The compressor side. Rheem’s steps check the fan, the filter and signs of a refrigerant leak, then the unit is replaced if the compressor has failed.

A101 to A106. Sensor failures, checked with an ohm reading against Rheem’s chart.

A125 to A129. The elements, their wiring and their relays. Element replacement itself is familiar work: how to test and change a water heater element.

A200. The ECO has tripped on high water temperature. Rheem’s steps check the elements to ground and the thermistors, then the board.

A502, A503 and the A900 codes. The controller. Rheem’s answer for most of them is a new control board.

What each one costs

The fix	Cost
Filter washed, tank purged, mode reset	Nothing
Failed compressor or refrigerant leak	A new heater, Rheem does not repair the sealed system

Questions people ask

What does A008 mean on a Rheem hybrid water heater?

A dry fire condition: not enough water in the tank. Rheem says to fill it and run a hot water faucet to purge the air, and to purge again if the code stays.

What does T131 mean?

A reminder to clean the air filter. Set the mode to Electric or OFF, wash the filter with a mild detergent, dry it, refit it and set your mode again.

What does A108 mean?

The condensate is blocked. The heater falls back to its elements until the condensate line is clear and the pan has drained.

What does A107 mean?

Water has been detected in the drain pan. Check for a leak. Rheem says holding the Clear Alarm button for 5 seconds overrides the alarm for 24 hours.

Why is my Rheem hybrid only using the elements?

Many of Rheem’s alarms switch it to the elements, including the compressor, airflow, heat pump sensor and condensate codes. Check the current alarms to see which one.

What does A200 mean?

The high limit, the ECO, has tripped on high water temperature, and the heater is disabled. Rheem’s display says to call tech service.

Sources: Rheem use and care manual AP23657 Rev 01, electric residential hybrid water heater