Alan Hart, I have the pleasure of returning to Viva Training for another insightful session on gas training and boiler fault finding. I’m here with Roy, a seasoned expert trainer, and Ryan, who will be assisting us in diagnosing some issues with this particular boiler.
Roy has spent numerous years mastering his skills and sharing his knowledge as a trainer, making him a true expert in handling these boilers. In this video, we will delve into understanding the fault code E110, exploring how to test for it, and discussing potential faults that may arise in the boiler.
When confronted with a boiler malfunction, it is crucial to ensure that all safety precautions are taken. Ensure that the boiler is isolated from power sources, and always use a multimeter to confirm that there is no electrical connection before proceeding with any repairs.
Upon ensuring safety, observe the boiler’s display panel for error codes or irregularities. This boiler displays an E110 error code, often related to overheating issues. Remember that different boilers may have unique error codes, so it’s essential to refer to the manufacturer’s guide or manual for accurate interpretation.
With the safety measures in place, begin by identifying and testing various boiler components. Start with the Printed Circuit Board (PCB), ensuring that it is in good condition and free from any burn marks or damage. Follow this by checking the pump and ensuring that it is not seized. A seized pump can lead to overheating and potentially cause the E110 error.
The next component to check is the heat exchanger. Ensure it is not blocked, as a blocked heat exchanger can also lead to overheating issues. If all these components are in good working condition, check the overheated thermostat.
The overheat thermostat is a critical component, and its proper functionality is crucial for the boiler’s operation. To test it, use a multimeter set to measure ohms and check the resistance across the thermostat’s terminals. Ensure that you have safely isolated the boiler before conducting this test.
The resistance should be over 1.5 ohms. If it isn’t, refer to the floor return sensors section in the manual. If it is over 1.5 ohms, replace the safety thermostat. When testing, always disconnect the component to avoid false readings, especially when dealing with thermistors and gas valves.
Proceed to access the thermostat by removing the front panel of the boiler and unplugging the two red wires connected to the thermostat. The thermostat works as a switch, remaining closed at normal temperatures and opening when temperatures exceed 105 degrees Celsius. This is a safety mechanism to prevent damage from overheating.
If the thermostat is not resetting itself after cooling down, it should be replaced. Some models may have a manual reset button, so check for that before replacing the component.
Before installing the new thermostat, test it with the multimeter to ensure it is in working condition. Check the resistance in your leads as well to avoid any false readings. Once confirmed, replace the old thermostat with the new one, ensuring proper alignment and connection of the wires.
After securing the new thermostat in place, restore power to the boiler and run a series of tests to ensure that both hot water and central heating are functioning correctly. Observe the boiler’s operation and ensure it ramps to the appropriate temperature and modulates as needed.
Viva’s 3-day intensive Boiler Fault Finding Course is ideal for gas installers who want to develop their technical skills to offer an improved central heating system maintenance and repair service.