There are a few issues that go wrong with hot water cylinders. Among the most common are a leaking hot water cylinder, no hot water available or heating too slowly to name a few. Below is an explanation to the most common problems and the reason for same.

hot water tanks cylinders
hot water tanks cylinders

Leaking Cylinder

It’s understandable to start panicking if you discover water your hot water tank is leaking. If water is leaking look for a red valve around the height of elbow to shoulder height. Turn it off clockwise until has fully stopped. Then run your hot water tap and in 30 seconds to 1 minute the hot water should stop coming from the tap. This may not stop the leak entirely as there is till a body of water still inside the copper tank.

Deposits of limescale and calcium in copper cylinders will over time result in corrosion to the tank and weakening it over time which may eventually lead to a leak. Also signs such as a blue colour appearing in your copper hot water tank otherwise known as oxidation can weaken the cylinder and then starts to pit with holes. This is a good early warning sign that your hot water cylinder needs replacing.

The copper or plastic pipes feeding or leaving the cylinder can corrode or if poorly installed can result in a leak. You will need to contact your local plumber to repair and replace the leaking pipes.

Another cause of a leaking hot water cylinder is when the primary heating coil of the cylinder from the central heating system has become over pressurised and the joints can start to weep and leak.

Contact 24 Hour Plumber in Dublin if your hot water tank is leaking. Our experienced plumbers will repair the source of the problem if possible or replace your damaged hot water cylinder if necessary or replacing hot water cylinder.

Tank Not Heating

If your hot water tank isn’t heating there can be a number of reasons. One of the most common is due to the immersion heater within the hot water tank and its thermostat. You might also want to consider pressing the reset button. This usually located near the thermostat.

Hot Water Quickly Runs Out

There is nothing more frustrating when you want to jump in the shower and find there is no hot water. When your hot water tank quickly runs out of hot water there are a few things you need to consider.

Reduced capacity

If your household has been using more hot water the obvious reason is due to your cylinders lack of capacity to provide enough hot water for the family. Your cylinder is simply too small and you may need to consider investing in a larger hot water tank to provide for your family’s needs.

You might also find that if a lot of hot water is being used within a small space of time your cylinder is also too small to deal with the demand for hot water. Consider using the shower at a different time to when washing the dishes for example.

Defect to Immersion Heater

Many hot hot water cylinders contain 2 immersion heaters. If one fails either due to age, faulty thermostat, or a build up of limescale and mineral deposits this just leaves one remaining immersion to heat the cylinder. You will find the water will either be very warm or run out very quickly.

Heating Slowly

one common problem that occurs with a hot water cylinder is when the hot water tank is heating slowly. Coming into the cold winter months one of our essentials is the hot water tank. Most of us rely on our hot water cylinder for all our hot water needs from showering, bathing, and washing. Below are a few reasons as to why your water is becoming slow to heat.

Throttling Valve

One cause of the water heating slowly involves the throttling valve on the heating coil from the central heating system has either become blocked or partially shut either by hand or by the formation of sludge.


The element of the immersion is coming to the end of its life as limescale and minerals build up on the element itself. This will happen at a much faster rate in areas of hard water. This will result in the water heating up at a slower rate compared to a new immersion heater.

Faulty Thermostat

If the thermostat reading is incorrect on the cylinder this will naturally affect the temperature of the water in the tank. A faulty thermostat will need to be corrected if someone has accidently knocked it or replaced if faulty.

Call us now for hot water cylinder replacing.