No Hot Water? How to Troubleshoot Your Unvented Cylinder

There’s nothing worse than stepping into the shower only to be hit with ice-cold water. If your unvented cylinder isn’t producing hot water, don’t panic. Many issues that can cause this problem have simple fixes. And there may not be a need to call for help just yet. Here’s how to troubleshoot the problem before calling in a professional.

1. Check the Power Supply

If you have an electric unvented cylinder, the first thing to check is whether it’s getting power. Look at the fuse box. Has a breaker tripped? If so, reset it and see if the problem is resolved. Note that if the breaker flips several times, it’s a sign that you need to call for help.

2. Inspect the Thermostat

A faulty thermostat means your cylinder won’t heat water properly. Try adjusting the temperature setting to 60°C. If there’s still no hot water, the thermostat might need to be replaced. This might be a good time to upgrade to a digital model if you’re still using an older, analogue-style thermostat. You can even install a programmable thermostat that can help make your system both more efficient and affordable to operate.

3. Look at the Heating Element

For electrically heated cylinders, the immersion heater (heating element) could be the problem. If you have power but no heat, the element may have burned out and need replacing. It may also be that the element is completely coated in debris from hard water. Many areas of the UK have mineral-rich water that can shorten immersion heater lifespan without regular maintenance.

4. Check for a Tripped Safety Cut-Out

Unvented cylinders have safety cut-outs to prevent overheating. If your cylinder has stopped heating, find the reset button (usually near the thermostat) and press it. If it keeps tripping, you may have a deeper issue. Like tripping breakers, safeties that keep tripping usually signal the need to call for professional assistance.

5. Is the Pressure Right?

Too little or too much pressure can prevent hot water from flowing. Check the pressure gauge. If it’s too low, you might need to recharge the expansion vessel. If it’s too high, a faulty pressure relief valve could be the issue. One sign that might point you toward the pressure relief valve is water flowing through the tundish.

6. Is the Boiler Working?

If your unvented cylinder is connected to a boiler rather than being a stand-alone unit, check if the boiler is running properly. A pilot light failure, pressure loss, or faulty pump can all stop hot water from reaching your taps. Anything that makes the boiler not work will affect your hot water.

7. Check the Mains

Sometimes, a lack of hot water is related to a problem with the flow from the mains. Close the hot tap and open the cold one. Is there water? If not, then your home isn’t getting any water at all, and you’ll need to check outside for the issue. In some cases, you may need to get in touch with your council about the problem.

When to Call a Professional

If you’ve checked these things and still have no hot water, it’s time to bring in an expert. Leaks, faulty components, or serious pressure issues require professional attention to prevent damage to your system.

Get Back to Hot Water Fast

Don’t suffer through cold showers! If your unvented cylinder isn’t working, contact EasyFlow today. Our expert team will diagnose the issue and get your hot water back in no time.