Unvented cylinder
repairs.
No hot water, a dripping discharge pipe or pressure problems? Book a repair visit by an engineer qualified for unvented hot water systems.
Common faults
- Water dripping from the discharge pipe or into the tundish
- No hot water, or hot water that runs cold quickly
- Low or surging hot water pressure
- Immersion heater not working
- Leaks from valves or fittings
- Noisy pipes or a hissing cylinder
These can come from a valve, the expansion vessel, a thermostat, the immersion heater or the boiler, so the cause is found first.
What you can safely do
- If water is dripping from the discharge pipe, don’t block or cap it – it is a safety outlet
- If there is a lot of very hot water coming out, switch off the boiler and the immersion heater and call us
- If there is no hot water, check the boiler is working and the immersion heater switch is on
- Don’t adjust or open the safety valves yourself
Smell gas? Leave the property and call the National Gas Emergency Service on 0800 111 999.
Send these details
- Cylinder make, model and size
- What is happening and when it started
- Photos of the cylinder, valves, tundish and discharge pipe
- Boiler make and model, and any fault code
- Full postcode, access and parking
Repair or replace?
Most faults can be fixed by replacing a valve, recharging the expansion vessel or fitting a new immersion heater. If the cylinder itself is leaking or badly corroded, it needs replacing.
See fixed replacement prices with our online cylinder price.
Who does the work
Work is carried out by one of our approved installation partners, registered for the work involved. Your written quotation names the installer, who your contract is with, and your warranty and workmanship guarantee. Parts and any further work are explained and priced before they go ahead.