Haier does not list a dedicated low water pressure error code for its Super Aqua heat pumps in the manuals we checked. Low pressure is more likely to show up as a low water flow fault, such as E08, so check the pressure gauge first and then book an engineer if the fault keeps returning.
If it keeps coming back, book an engineer rather than topping up or restarting repeatedly. You can book a heat pump repair online or call 0333 041 5130, and our full Haier heat pump error codes guide covers every other code.
Please read first: this is a guide only. We make every effort to keep it accurate, but manufacturers update manuals and codes differ between models and software versions, so always check the official Haier manual for your unit. Do not attempt anything dangerous or anything that could void your warranty.
Is there a Haier error code for low water pressure?
No. We checked Haier’s Super Aqua monobloc and split documentation and found no code described as low water pressure, so we are writing this as a general low pressure guide. Where we mention a code, it is a flow or water circuit code that low pressure can lead to.
The closest is E08, shown in Haier’s R290 Super Aqua service manual as Flow Switch Abnormality or Low Water Flow. The manual says the fault is raised when there is no water flow signal after the water pump has been running for 120 seconds. It is resumable, meaning it can clear once the flow is normal for 5 minutes, but if it occurs 3 times in an hour the failure is confirmed. The manual’s troubleshooting notes cover checking that the system has water, that the flowmeter reads, and that the pump is not stuck, since crystallisation can build up on the pump rotor after a long shutdown or with poor water quality.
The service manual also lists E13 as water leakage, marked as reserved, triggered when a micro switch input stays closed for 60 seconds. The older Super Aqua monobloc installation manual numbers its codes differently, listing flow switch abnormal, flow rate too low, system leak water and DC water pump failure as separate entries. That is a good example of why codes differ between models and software versions, and why you should match yours to the manual for your exact unit.
On pressure figures, the monobloc manual we read states only that the maximum water pressure is 5 bar, the nominal opening pressure of the safety valve. We found no minimum or fill pressure for Haier in the documents available, so your installer’s commissioning figure and the gauge label are your best guide. As a cautious general rule, a sealed system gauge sitting near zero is certainly too low.
Why does a Haier heat pump lose water pressure?
With no code to narrow it down, the reasons for a Haier system losing pressure are the same as for any sealed heat pump circuit:
- A leak at radiators, valves, joints, underfloor manifolds or the hydraulic connections.
- A failing expansion vessel that has lost its charge. Haier’s split manual notes an additional expansion tank is needed where system capacity exceeds 180 litres.
- Air in the system after filling or work, which can also trigger the E08 flow fault.
- A safety valve discharging after the pressure was pushed too high.
- Recent bleeding or radiator work that removed water.
- A leaking automatic air vent.
- A blocked filter or stuck pump, which affects flow and often gets blamed on pressure.
Because Haier controllers monitor flow rather than pressure, a modest pressure loss may not trigger any alarm until the circuit is nearly empty. Checking the gauge yourself is the earliest warning you will get.
What can you safely check yourself?
These checks need no tools and no panels removed. If you are not comfortable with any step, stop and call an engineer.
- Look at the pressure gauge when the system is cold and compare it with the figure your installer left or noted at commissioning.
- Note any code such as E08 and when it appeared.
- Check for drips and damp around radiators, pipework, the indoor unit and safety valve outlet.
- Confirm radiator and zone valves are open and no isolation valve has been closed.
- Top up only if the manual allows it and you are competent, using the filling loop slowly and closing it fully afterwards.
- Recheck the gauge the next day. A drop means the system is still losing water.
Our guide to why a heat pump keeps losing pressure goes into the repressurising process and what a normal rate of loss looks like.
What not to do:
- Do not attempt any refrigerant work. Refrigerant handling is for F-Gas certified engineers only, and a low water pressure fault is not a refrigerant fault.
- Do not remove the outdoor unit or indoor unit panels. Live electrics, moving parts and pressurised components sit behind them.
- Do not keep over-pressurising to be safe. Pushing the gauge towards the maximum can lift the pressure relief valve and stress joints.
- Do not ignore repeated top-ups. If you need to refill the system more than once or twice a year, water is escaping somewhere and it needs finding.
When should you call an engineer?
- E08 or another flow fault appears more than once.
- The gauge falls after a top-up.
- The safety valve is dripping.
- The heat pump has stopped heating and hot water.
- You can see water leaking.
- You do not know what pressure your Haier should be at.
Booking early matters here. A small leak caught in week one is usually a cheap fix, while months of topping up can let air and fresh oxygen into the circuit and cause sludge and corrosion.
How can you stop it happening again?
- Book an annual service. See our annual service checklist for what is covered.
- Fix drips early, using our heat pump leaking water guide.
- Keep the circuit clean. A heat pump powerflush can help if the water is dirty or the pump is struggling.
- If it stops delivering heat, see our heat pump not heating guide.
- Check the gauge monthly and note the reading.
Other Haier codes you might see with low pressure
Haier lists no pressure code, so these are the water circuit and flow codes we could confirm in Haier’s Super Aqua documentation.
| Code | Meaning | First step |
|---|---|---|
| E08 | Flow Switch Abnormality or Low Water Flow: no flow signal after the pump has run for 120 seconds. Confirmed if it happens 3 times in an hour. | Check the gauge and valves, then book an engineer to check for air, the filter and the pump. |
| E13 | Water leakage (marked reserved): micro switch input stays closed for 60 seconds. Unresumable. | Look for visible leaks and call an engineer. |
Numbering and wording differ between Haier models, so use the manual for your exact unit before relying on any table here.
Need help with low pressure on a Haier heat pump?
UK Heat Pump Servicing engineers find the leak, check the expansion vessel and air vent, and carry out heat pump repairs with a 12-month guarantee. We repair Haier heat pumps, finding the leak, checking the expansion vessel and air vent and restoring the correct system pressure. Our annual heat pump service catches pressure problems before they stop your heating, and we also offer cover plans if you would rather spread the cost of looking after the system. If your gauge is low or a code is showing, contact us or call 0333 041 5130.
Frequently asked questions
Does Haier show a pressure reading on the controller?
The documents we reviewed describe flow monitoring rather than a pressure display, so use the system pressure gauge on the pipework. Your installer can show you where it is.
What does a flashing flow fault mean if the pressure is fine?
It usually points to air, a blocked filter, a closed valve or a pump that is not turning. An engineer can measure the flow and find which.
Can poor water quality cause these faults?
Haier’s troubleshooting notes say poor water quality can cause crystallisation on the pump rotor, which can stop it starting. A clean, treated circuit helps prevent this.
Is it safe to keep resetting the unit?
Occasionally resetting after a refill is fine, but repeated resets hide the cause. After three flow faults in an hour the unit confirms the failure, so get an engineer in.
What is the safety valve pressure on a Haier monobloc?
The manual we read gives a maximum water pressure of 5 bar, the nominal opening pressure of the safety valve. Your system gauge should sit well below that.
