Unvented Cylinder Repair

What unvented cylinder repair covers

Unvented cylinders operate under mains pressure and include safety controls that must work correctly. This service is designed to identify the cause of the fault and complete the right repair first time.

It typically includes:

• Fault diagnosis for loss of hot water, low pressure, leaks, or unusual noises
• Checks of key safety components (expansion vessel, pressure reducing valve, temperature and pressure relief valve)
• Repair or replacement of failed parts such as valves, tundish connections, thermostats, immersions, or pumps (where fitted)
• Investigation of discharge pipework issues and nuisance dripping
• Testing and commissioning after repair to confirm safe operation

When this service is most useful

Book an unvented cylinder repair if you have intermittent hot water, fluctuating temperature, reduced flow at hot taps, or water discharging through the tundish. It is also relevant if the system is frequently repressurised, you notice damp around the cylinder, or you have repeated trips on an immersion heater.

What to expect during the repair

The visit starts with structured fault finding and visual checks of the cylinder, controls, and discharge pipework. Once the issue is confirmed, you will be talked through the options and any parts required before work goes ahead. Repairs are completed using the correct unvented procedures, then the system is tested so you can be confident it is operating safely.

After the repair: keeping the system reliable

After the fix, you will receive practical advice on preventing repeat faults, such as maintaining correct pressures and spotting early warning signs. If the system is due for servicing, you can plan it to help reduce callouts and extend the life of components.