Unvented Cylinder Service

What an unvented cylinder service covers

A proper service focuses on safety devices first, then performance and reliability. Depending on your cylinder model and installation, your service may include:

• Visual inspection of the cylinder, pipework and controls for leaks, corrosion and heat damage
• Checks of key safety components (temperature and pressure relief, expansion relief and associated discharge pipework)
• Testing and setting of pressures where applicable, and checks of the pressure reducing valve and line strainer
• Assessment of the expansion vessel or internal air gap arrangement
• Checks of thermostats, immersion heater controls and hot water temperature stability
• Inspection of motorised valves, check valves and associated fittings around the unvented kit
• System performance checks, plus fault diagnosis where symptoms have been reported
• Clear service notes and recommendations for any repairs or parts that are nearing end of life

When this service is most relevant

This service is a good fit if your cylinder is due its annual check, if you are a landlord managing safety responsibilities, or if you have noticed issues like fluctuating temperature, dripping tundish, banging pipework, reduced hot water flow, or frequent pressure changes. It is also sensible after a property purchase, a period of vacancy, or any recent works to the hot water system.

What to expect during the visit

You can expect a structured, safety-led approach. The engineer will isolate water and power as needed, inspect the installation, then test and verify the operation of the safety devices and controls. If you have specific symptoms, these will be checked during the visit, and you will be told what has been found and what needs doing next before any additional work goes ahead.

After the service

You will receive a clear summary of results and any actions to keep the system safe and dependable. If parts are worn or failing, you will be advised on repair options and likely timescales. Many clients use the annual service as a prompt to schedule future checks, keep records for compliance, and avoid unexpected loss of hot water.