An unvented cylinder stores hot water at mains pressure. Its safety devices, including the temperature and pressure relief valve, expansion relief valve and thermal cut-outs, are what keep it safe.
What we check
- Incoming mains pressure and the pressure-reducing valve
- Expansion vessel charge
- Operation of the temperature and pressure relief valves
- Tundish and discharge pipework
- Thermostats and thermal cut-outs
Warning signs
Water running through the tundish (the small funnel near the cylinder), hot water from the discharge pipe outside, or banging noises. Switch off the boiler and immersion heater and call us straight away.