Samsung EHS heat pumps show faults as an E-code, such as E911 or E554, on the wired remote controller, and pressing its Test button displays the code. The number tells you roughly where the problem sits: E1xx and E2xx are communication and indoor sensors, E4xx and E5xx the outdoor unit and refrigerant circuit, E6xx the remote controller and E9xx the hydro unit and water flow.
If a code keeps returning, or you are not sure what it means, book an engineer rather than guessing. We repair Samsung systems across the UK and you can book a heat pump repair online or on 0333 041 5130. For other makes, our heat pump error codes hub covers the main brands.
Safety first: never remove the casing of the outdoor unit or hydro unit, and leave anything electrical to a qualified engineer. This guide is based on Samsung's documents for the EHS Mono range, so meanings may differ slightly on other models.
Please read first: this guide is here to help you understand what your Samsung heat pump is telling you. Every effort has been made to keep the information accurate, but manufacturers update their manuals and codes can differ between models and software versions, so always check the official Samsung manual for changes before acting on anything here. Do not attempt anything that could be dangerous, and avoid any work that could void your warranty. If in doubt, call a qualified heat pump engineer.
If your Samsung heat pump is not showing a code, or you want to rule out the basics first, our guide to why an air source heat pump stops working walks through the general checks and matches common faults to error codes across every major brand.
Is it safe to fix a Samsung heat pump fault yourself?
Only basic checks are safe for most homeowners; the repair itself is engineer work. Reading the code, checking the pressure gauge, opening valves and clearing leaves or snow from around the outdoor unit are fine. Anything beyond that needs someone competent.
Never open the unit to reach the electrics. Many Samsung codes point at inverter boards and compressor wiring, which can hold a dangerous charge even after the power is off.
Refrigerant work is legally restricted to F-Gas certified engineers, so codes such as E554 and E439 are never DIY. Unqualified work inside the unit can also cause problems with your manufacturer warranty, so check its terms first.
Which Samsung error codes can you check yourself?
Only a handful of Samsung codes have a realistic homeowner check, mostly around water flow, airflow, power and the hot water schedule. Do the check once, then call us if the code returns.
| Code | What it means | Safe homeowner check | Stop and call an engineer if |
|---|---|---|---|
| E911 | Low water flow through the hydro unit | Check the pressure gauge and that radiator and zone valves are open. Top up only if you have a filling loop and your manual allows it | Pressure keeps dropping or the code returns |
| E907 | Pipe rupture protection | Look for drips under the hydro unit, at radiators and on visible pipework, and check the gauge | You find a leak or pressure is low |
| E908 | Freeze prevention, unit can restart | Make sure the unit has power and the breaker has not tripped | It changes to E909 or keeps repeating |
| E919 | Hot water tank disinfection not completed | Avoid large draw-offs during the scheduled cycle and do not stop it manually | It shows after every cycle |
| E601 | Remote controller and indoor unit communication error | Switch off at the isolator for a few minutes, then back on | It returns after the restart |
| E500 | Inverter overheat in the outdoor unit | Clear anything blocking airflow around the outdoor unit | It returns once airflow is clear |
| E915, E458, E475 | Outdoor fan not running or fan error | From outside, look for ice, leaves or debris blocking the fan. Do not reach inside | The fan stays still with nothing blocking it |
What are the most common Samsung heat pump error codes?
The Samsung codes we see most involve water flow, freezing, sensors and communication. Causes start with what Samsung states; anything marked general engineering knowledge comes from our experience, not the manual.
E911: low water flow
The pump is running but too little water is moving. Samsung triggers it 30 seconds after pump start, or after 15 seconds of low flow once running.
Likely causes: Samsung lists an unseated or open flow sensor, a pump that is not running and low flow. Its installer guide adds that lime can seize the pump rotor after a long standstill. General engineering knowledge: air locks, a clogged strainer, sludge and closed zone valves are the usual underlying causes.
What to do: Check the pressure gauge and valves. If it returns, an engineer will bleed the system, clean the strainer and test the pump, and heavy sludge may call for a heat pump powerflush. Six flow errors in a row trigger E913, a lockout that needs the cause fixed before a reset.
E908 and E909: freeze prevention
Both mean the unit has acted to protect itself from freezing. With E908 the unit can run again; with E909 it cannot.
Likely causes: Samsung gives no further detail. General engineering knowledge: weak glycol (antifreeze) concentration, poor pipe insulation and loss of power, since freeze protection needs electricity to work.
What to do: Keep the unit powered through cold spells. E909 needs an engineer, and our guide to a frozen outdoor unit explains what to do and avoid in the meantime.
E403: outdoor freeze or overload protection
The outdoor unit has stopped to protect itself from freezing or overload. Third-party installer sources link it to low refrigerant charge, poor airflow and a blocked coil.
What to do: Check the coil is not buried in snow, ice or leaves. If it is clear and the code persists, an F-Gas engineer needs to check the refrigerant cycle.
E907: pipe rupture protection
Samsung names this code without giving causes. General engineering knowledge: leaks, low system pressure and a failing expansion vessel are the usual reasons.
What to do: Check the gauge and look for drips. If pressure keeps falling, read our guide to a heat pump losing pressure and book a visit.
E901, E902 and E904: water sensor faults
E901 is the water inlet sensor, E902 the outlet sensor and E904 the hot water tank sensor, each reading short or open circuit. Samsung's remedy is to check the connector, then replace the sensor or PCB using its resistance tables.
What to do: There is no homeowner fix, so book an engineer.
E101, E203 and E601: communication faults
E101 means the hydro unit gets no data from the outdoor unit, E203 is a fault between two outdoor boards and E601 is a break between the remote and the indoor unit. Third-party sources point to cable, PCB and loose wiring faults; for E203, a Samsung service manual says to isolate power for two minutes and check the 6-core cable.
What to do: A restart may clear E601. Repeat communication codes need an engineer, who will check cable joints and any recent electrical work first.
E407: high pressure protection
Refrigerant pressure has gone too high and the compressor has stopped. Third-party sources link it to blocked heat exchangers, overcharge and fan failure; general engineering knowledge adds poor water flow, because the heat has nowhere to go.
What to do: An engineer should check flow first, then the refrigerant circuit.
E554 and E439: refrigerant leak
E554 is a gas leak error and E439 is a leak detected while the system is idle. Both need an F-Gas certified engineer, and E554 should be treated as urgent.
Which error code might you see in common situations?
These are the Samsung codes most likely in everyday situations. Do the first check, then call us if the code stays.
| Scenario | Codes you may see on a Samsung | First check |
|---|---|---|
| Cold snap and iced outdoor unit | E908, E909, E403, E436 | Keep the unit powered and clear snow from around it. Do not chip ice off the coil |
| Losing pressure or low pressure | E907, E911 | Read the gauge and look for drips at the hydro unit and radiators |
| Radiators lukewarm | E911, E407, E507 | Check pressure and that radiator and zone valves are open |
| No hot water | E904, E917, E919 | Check the hot water schedule and avoid draw-offs during disinfection |
| After a power cut | E101, E102, E601, E466 | Give the system a few minutes to restart and check the breaker |
| Unit noisy or fan not spinning | E458, E475, E915 | Look for ice or debris around the fan from outside |
| After a service or filter clean | E911, E912, E910 | Check that isolation valves were reopened and pressure is back up |
Pump noise with no code can be cavitation, which Samsung links to air in the system and pressure below 1 bar. Our guide to a heat pump making noise covers other causes.
How do you reset a Samsung heat pump?
Samsung publishes very little on resets, so most should follow a fix by an engineer. The one reset its installer guide describes is for a tripped back-up heater thermal protector: check water pressure and air in the system first, then press the reset button in the switch box. The switch box sits inside the unit, so this is engineer territory.
Some codes behave differently. E913 will not clear on its own until the flow fault is fixed and the unit reset, and E909 does not allow the unit to run again. For E601, one third-party installer source suggests switching off the power for five minutes; for E500, Samsung's remedy is letting the inverter board cool before restarting.
Resetting over and over without fixing the cause is a bad idea. It strains the compressor and pump, and repeated flow errors trigger the E913 lockout.
Samsung error code list
This list covers the codes in Samsung's installer guide and hydro unit service manual. Meanings can vary by model, and one third-party list numbers codes from E913 onwards differently, so check your manual if a description does not match.
| Code | Meaning | Who should fix |
|---|---|---|
| E101, E102, E110, E201, E202, E203, E205 | Communication between units, boards or the control kit | Engineer |
| E108, E161 to E163 | Address, operating mode, EEPROM or option setting error | Engineer |
| E120 to E123, E128 to E130 | Room and EVA sensors short, open or detached | Engineer |
| E151, E152, E438 | Electronic expansion valve error | F-Gas engineer |
| E177 | Emergency stop in hydro box, check circulation | Engineer |
| E185, E198 | Wiring error or thermal fuse disconnected | Engineer |
| E221, E231, E251, E308, E320 | Outdoor unit temperature sensors | Engineer |
| E291, E296 | High or low pressure sensor | F-Gas engineer |
| E403 | Outdoor freeze or overload protection | Homeowner check, then F-Gas engineer |
| E407, E410, E416, E428, E443 | Refrigerant pressure or discharge temperature protection | F-Gas engineer |
| E425 | Reverse or missing phase | Engineer |
| E436 | Freeze burst protection | Engineer |
| E439, E554 | Refrigerant leak | F-Gas engineer, urgent |
| E440, E441 | Heating blocked above 43C outside, cooling blocked in low temperatures | No fault, wait |
| E458, E475, E915 | Outdoor fan error or fan not running | Homeowner check, then engineer |
| E461 to E471, E474, E483 to E485, E488, E590 | Compressor, inverter, voltage and memory faults | Engineer |
| E500 | Inverter overheat | Homeowner check, then engineer |
| E507 | Compressor stop on high pressure | Engineer |
| E563, E618, E627, E633 | Mixed units or too many units or remotes | Engineer |
| E601, E602, E604 | Remote controller communication | Homeowner check, then engineer |
| E653, E654 | Remote controller sensor or data error | Engineer |
| E899, E900, E901, E902, E904, E906, E910, E916 | Zone, inlet, outlet, tank, EVA-in or mixing sensor | Engineer |
| E907 | Pipe rupture protection | Homeowner check, then engineer |
| E908 | Freeze prevention, can restart | Homeowner check |
| E909 | Freeze prevention, cannot restart | Engineer |
| E911 | Low water flow | Homeowner check, then engineer |
| E912, E913 | Flow with pump off, flow lockout | Engineer |
| E914, E917 | Thermostat wiring or tank sensor setting | Engineer |
| E919 | Tank disinfection not completed | Homeowner check |
Where can you find the official Samsung manual?
Samsung publishes the installation manual for its R32 EHS Mono outdoor units on its UK support site. Search your own model number there, as documents vary between models.
- Samsung EHS R-32 Mono outdoor unit installation manual (PDF)
- Samsung UK support page for the AE160RXYDEG/EU EHS Mono unit
Need help with a Samsung heat pump fault?
We repair Samsung heat pumps across the UK, from single error codes to systems that have stopped altogether. Our F-Gas certified engineers diagnose the fault properly, explain what they find and carry out Samsung heat pump repairs with a 12-month guarantee on the work.
If the heating has failed in cold weather, our emergency heat pump repair service offers same-day visits where possible. You can also read more about the systems we work on in our Samsung heat pump service page and our Samsung heat pump review.
Many of the codes above, especially flow, sensor and airflow faults, are caught early at an annual heat pump service. Our cover plans bundle servicing and repairs. To book, contact us or call 0333 041 5130.
Frequently asked questions
Will a Samsung error code void my warranty?
A code on its own does not void anything; it is the heat pump protecting itself. Warranty problems usually come from unqualified repairs or missed servicing, so check your terms.
Does an E4xx code mean the compressor has failed?
Not necessarily. Samsung's own remedies for these codes start with compressor wiring, input power, the reactor and the inverter board, and many turn out to be supply or board faults. Our guide to heat pump compressor problems explains the warning signs of a genuine failure.
Can I keep using my Samsung heat pump while it shows a code?
Some codes stop the unit and others let it carry on. If it has stopped, do not keep restarting it; book a check instead.
How long does a Samsung heat pump repair take?
Flow, sensor and wiring faults are often fixed in one visit. Board, fan and compressor faults may need parts ordering, and we will tell you what to expect after diagnosis.
What should I note down before calling an engineer?
Note the exact code, when it appeared, the pressure gauge reading and the weather. A photo of the unit's rating label helps us bring the right parts.
