A Guide to the GAH Electrastream System: Common Issues and Fixes

We regularly maintain and repair GAH Electrastream systems for a customer who manages an apartment block with 22 individual units. Each apartment has a GAH Electrastream control unit paired with an Ariston Primo Cylinder, which functions similarly to a thermal store but with a pressurised water store. This article provides an overview of how these systems work, common issues we encounter, and troubleshooting advice.

How the GAH Electrastream System Works

The GAH Electrastream is an electric wet central heating and hot water system designed for properties without mains gas. It operates by using a pressurised water store to deliver both heating and hot water efficiently.

The system relies on a three-element immersion heater, which is controlled by the Electrastream unit. These elements heat the stored water, which is then circulated to radiators for central heating. The domestic hot water does not mix with the stored water; instead, it passes through a coil inside the cylinder, where it is heated indirectly. This setup ensures that the domestic water supply remains separate from the stored heating water.

One key feature of the Electrastream is that it integrates both heating and hot water within a single unit, reducing the need for separate boilers and cylinders. However, due to their complexity, these systems can be difficult to troubleshoot and repair.

GAH Electrastream Error Codes and Their Meanings

When the Electrastream control panel displays an error code, it typically indicates a fault that needs professional attention. Here are the most common errors and their causes:

• ERROR 1 – Faulty or disconnected temperature sensor. Heating is disabled.

• ERROR 2 – Indicates one of the following:

  1. A blown auxiliary 5A fuse.

  2. A fault with the pump, motorised valve, or room thermostat. Heating is disabled until resolved.

• ERROR 3 – All heater elements have failed the heater test. Heating is disabled.

• ERROR 5 – One or more of the controller buttons (‘Set’, ‘Up’, ‘Down’, or ‘Boost’) is stuck or being held down.

• HEAT 1 ! (or HEAT 2 ! / HEAT 3 !) – A tri-core heating element has failed. This could be due to a tripped thermal cut-out. Check the resettable thermal trips in the Electrastream Control Unit.

If any of these errors appear, a professional should investigate further, as the system will remain disabled until the fault is rectified.

Common Issues with GAH Electrastream Systems

Through our experience, we have identified several common faults with these systems. Here’s what to look out for:

1. All Three Elements in the Immersion Heater Have Tripped

On later versions of the Electrastream control panel, a series of reset switches run down the right side of the unit. If an element has tripped, pressing the reset button will produce a clicking sound. However, earlier versions lack these resettable cut-outs and instead use a 16A fuse for each element. Replacing these fuses requires removing the front cover of the control unit, which should only be done by a professional.

It’s important to note that if an element trips, it has done so for a reason and is likely to trip again unless the underlying issue is resolved. Common causes include:

• Split or damaged elements – A new element will be required (and they are expensive).

• Scaling of the elements – Overheating due to limescale buildup. In such cases, the cylinder and elements can be descaled using Fernox DS-3.

• Leaks from the thermostat pocket – If water has leaked onto the electrics, this will need to be addressed.

These cylinders are unvented, meaning only a G3-certified engineer should work on them.

2. Error 1 – Faulty Temperature Sensor

When ‘Error 1’ appears, the issue is usually caused by a pinhole leak in the thermostat pocket where the temperature sensor is housed. This leak damages the sensor, leading to failure.

3. Heating Works but No Hot Water

If the heating is operational but no hot water is available, the issue is nearly always with the Thermostatic Mixing Valve (TMV). This component is located on the pipework next to the cylinder and is responsible for blending hot and cold water to a safe temperature.

Are GAH Electrastream Systems Worth Repairing?

Despite their drawbacks, we believe Electrastream systems are well-built and have served many properties well. The ones we maintain are nearly 20 years old and have proven to be reliable when properly maintained. However, there are some significant downsides:

• They are no longer manufactured – Spare parts are difficult to obtain and costly when available.

• They are complex to set up and repair – Not many engineers have experience with them.

• Technical support is poor – The system was acquired by Stuart Turner, but their support team has little knowledge of the product. Expect long wait times (often over 30 minutes, and in some cases over an hour) if you need assistance.

If your Electrastream unit is failing frequently, it may be worth considering alternative heating solutions, such as:

• Electric boilers with separate cylinders – More modular and easier to service.

• Air source heat pumps – If space and budget allow, these can be a highly efficient alternative.

• Modern thermal store systems – More readily available and better supported.

Conclusion

GAH Electrastream systems can be a viable heating and hot water solution for properties without mains gas, but they come with challenges. Understanding common faults and error codes can help diagnose problems quickly, but due to the complexity of these systems, professional maintenance is strongly recommended.

If you own or manage a property with an Electrastream system and need servicing or repairs, seek out an experienced engineer who is familiar with these units. Given their age and the cost of parts, it may also be time to explore replacement options if problems become frequent.

Need Help with Your Electrastream System?

If you’re experiencing issues with a GAH Electrastream system and you’re based in East Yorkshire or North Lincolnshire, we can help. With extensive experience in servicing and repairing these systems, we can diagnose faults, source replacement parts, and provide expert repairs.

Contact us today to discuss your Electrastream issues and arrange a service visit.