Samsung EHS Heat Pump Problems — Faults & Fixes
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Post a job — we'll find you an engineer →Refrigerant faults require an F-Gas certified engineer. Do not access internal components of the outdoor unit.
Samsung's EHS heat pump and ClimateHub are popular choices for UK homes looking to switch to renewable heating, but like any modern heating system, they occasionally throw up fault codes or connectivity hiccups that leave homeowners scratching their heads. Most problems fall into a few categories: water flow errors (usually caused by airlocks or closed valves), refrigerant pressure faults (which need specialist attention), hot water temperature issues, or app connectivity glitches. The good news is that many of these can be diagnosed and fixed without calling an engineer — though some faults, particularly anything involving the refrigerant circuit, must be handled by an F-Gas certified professional. This guide walks through the most common Samsung heat pump issues you'll encounter, what the error codes mean, and which ones you can safely troubleshoot at home.
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Most likely cause & what to check
Samsung's residential heat pump range in the UK is the EHS (Eco Heating System) Gen 6 and the ClimateHub (which combines a heat pump with an integrated 200-litre cylinder). The ClimateHub is particularly popular for its compact all-in-one design. Technical support at samsung.com/uk/business/hvac/support or call Samsung HVAC on 0333 000 0800.
Error code E121 / E122 (water flow error): the heat pump cannot detect adequate water flow. Check all isolation valves are open, system pressure is in range (1.5–2.5 bar), the circulation pump is running, and the system is free of airlocks. Bleed radiators if needed.
Error code E407 (high pressure): the refrigerant discharge pressure is too high. Check the outdoor unit is not obstructed by vegetation, dirt, or snow. If clear, an F-Gas engineer should check refrigerant charge.
ClimateHub not producing hot water: the Samsung ClimateHub uses the heat pump to heat domestic hot water as well as space heating. If hot water is cold, check the hot water schedule in the Samsung SmartThings app or controller, and confirm the cylinder thermostat target temperature is set correctly (55°C is typical for legionella compliance).
Samsung EHS not communicating with SmartThings app: connectivity issues are usually router or app related. Ensure the MIM-H04 Wi-Fi module is installed and paired. Try re-adding the device in the SmartThings app. This is not a heat pump fault.
Samsung EHS warranty: 5-year parts and labour warranty when installed by a Samsung-registered MCS installer. Annual servicing is recommended. For warranty support contact Samsung HVAC directly.
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Frequently asked questions
What should I do if my Samsung heat pump shows an E121 or E122 error?
These codes indicate water flow problems, usually caused by a closed isolation valve, low system pressure, or trapped air. Start by checking that both isolation valves (inlet and outlet) on the heat pump are fully open, then check your system pressure gauge reads between 1.5 and 2.5 bar. If pressure is low or you suspect an airlock, bleed your radiators and run the pump on high speed to shift trapped air.
Can I fix a refrigerant pressure fault myself?
No — error codes like E407 (high discharge pressure) indicate a refrigerant issue and must be handled by an F-Gas certified engineer. Do not attempt to access the outdoor unit's internal components. Contact Samsung HVAC support or your installer to arrange a visit.
Why is my ClimateHub not producing hot water?
Check the hot water schedule in your Samsung SmartThings app or physical controller — it may simply be set to off during certain hours. Verify that the cylinder thermostat target temperature is set correctly (55°C is the standard for legionella compliance). If both are correct but water remains cold, contact your installer as the issue may be with the heat pump's domestic hot water circuit.
My Samsung heat pump won't connect to the SmartThings app — is it broken?
Connectivity issues are rarely a fault with the heat pump itself; they're almost always router or app-related. Confirm the MIM-H04 Wi-Fi module is installed and paired correctly, restart your router, and try removing and re-adding the device in the SmartThings app. If you're still stuck, check your Wi-Fi signal strength near the outdoor unit.
How often should my Samsung EHS be serviced?
Annual servicing is recommended to keep your system running efficiently and maintain warranty cover. Your Samsung-registered MCS installer can arrange this, and the system comes with a 5-year parts and labour warranty from installation date.