No Hot Water? How to Fix Your Boiler in the UK – Simple Steps

If your boiler isn’t giving you hot water, don’t panic! You can try some easy checks yourself before calling a professional.

This guide is for UK homeowners with a gas boiler or similar that’s not working properly.

We’ll cover how to check your gas boiler, pipes, thermostat, and more to get your hot water flowing again.

Why Is My Boiler Not Giving Me Hot Water?

There could be a few reasons your hot water has stopped. Maybe the boiler needs a reset, the pipes are blocked, or the thermostat isn’t working. Let’s break it down step-by-step so you can figure out what’s wrong and fix it.

Step 1: Check Your Boiler

Your boiler is the heart of your hot water system. Here’s what to look at:

Reset the Boiler

What to do: Many boilers have a reset button. It’s usually a big red or green button on the front. Press it and wait a few minutes to see if the hot water comes back. If you suspect an electric water heater malfunction, check the connections and circuit breakers as well.

Why it helps: This can fix small glitches and get your boiler working again.

Check the Boiler Settings

• What to do: Look at the dials or screen on your boiler. Make sure the time is correct and the timer is set to “on” when you want hot water. For a gas boiler, also check that the pilot light is on and there are no gas supply interruptions.
• Why it helps: If the settings are wrong, the boiler won’t heat water when you need it.

Check the Boiler Pressure

• What to do: Find the pressure gauge – it’s often a little dial with numbers (usually 0 to 4). It should be between 1 and 2 when the boiler is off. If the water pressure is too low (below 1 bar), there might be a problem.
• Why it helps: Low pressure can stop hot water. It might mean there’s a leak in the boiler or pipes.

Step 2: Check Your Pipes

Pipes carry hot water from the boiler to your taps. If they’re blocked or frozen, you won’t get hot water.

Look for Frozen Boiler’s Condensate Pipe

What to do: Feel the pipes near your boiler or outside. If they’re icy cold or you see frost, they might be frozen. Also, check your hot water tank to ensure it is functioning properly.

Why it helps: In the UK, cold winters can freeze pipes, stopping water from moving. You can thaw them with a hot water bottle or warm towel (never use a flame!).

Check for Blocked Pipes

• What to do: Look for pipes that feel unusually cold or don’t seem to be working. Listen for gurgling noises. Check the gas inlet valve and the gas supply tube to ensure they are not obstructed.
• Why it helps: Blockages stop hot water from reaching your taps. A plumber might need to clear them if you can’t.

Step 3: Check Your Thermostat

The thermostat tells your boiler when to heat water. If it’s broken, you’ll have no hot water or weird temperatures.

Test the Thermostat

What to do: Turn the thermostat up and down. Listen for a click from the boiler. If nothing happens, it might be faulty. Additionally, check the heating element for any signs of damage or mineral deposits.

Why it helps: A broken thermostat or a faulty heating element can stop the boiler from turning on, leaving you with cold water.

Step 4: Look for Leaks

Leaks can cause big problems with your boiler and hot water supply.

Check for Water Leaks

What to do: Look around the boiler and pipes for puddles, damp spots, or dripping water. Additionally, check the gas inlet valve to ensure it is properly positioned and functioning.

Why it helps: A leak can lower the boiler pressure and stop hot water from working. If you see a leak, turn off the water and call a plumber.

Check for Gas Leaks

• What to do: Sniff for a rotten egg smell near the boiler. Look at nearby plants or flowers – if they’re turning brown or dying, it could be a gas leak or an issue with the gas supply.
• Why it helps: Gas leaks are dangerous and can stop your boiler. If you suspect a gas leak, leave the house and call a gas engineer or the National Gas Emergency number (0800 111 999) immediately.

Step 5: Other Things to Check

If the steps above don’t work, try these extra checks:

Water, Gas, and Electricity Supply

• What to do: Make sure your home has water (check a cold tap), gas, and power. Check the power supply, including circuit breakers and fuses, as a tripped breaker or blown fuse can interrupt the power supply. If any are off, your boiler won’t work.
• Why it helps: No supply means no hot water – simple as that!

The Diverter Valve

• What to do: Turn on the hot water tap and listen to the boiler. If it doesn’t kick in but works for heating, the diverter valve might be stuck, leading to heating but no hot water.
• Why it helps: This valve switches between heating and hot water. If it’s broken, you’ll need a professional to fix it.

The Radiators

What to do: Feel your radiators. If they’re hot but your taps are cold, it could be a hot water issue, not a central heating one.

Why it helps: This narrows down the problem to the boiler’s hot water system.

What to Do If You Can’t Fix Your Boiler?

If you’ve tried everything and still have no hot water, it’s time to call a Gas Safe registered engineer. In the UK, only qualified professionals can fix certain boiler problems safely. Luckily, here at Green Central, we have a wide network of local Gas Safe registered heating engineers who are able to fix your boiler issues.

And if your boiler is over ten years old, out of warranty and starting to rack up huge repair bills, we can even offer you great deals on replacement boilers.

Boiler No Hot Water FAQs

Why does my boiler have no hot water but heating works?

This could be a stuck diverter valve or a hot water setting issue. Check the valve and settings first, and ensure other gas appliances in your home are functioning properly to rule out any gas supply issues.

How do I increase boiler pressure?

Look for a filling loop (a small hose under the boiler) and follow your boiler manual to add water until the pressure is 1-2 bar. Additionally, ensure the gas valve is functioning properly, as a faulty gas valve can also affect the boiler’s performance.

Can a frozen pipe stop my hot water?

Yes! Frozen pipes block water flow. Thaw them gently with warm water, hot water bottle or a towel.

Final Tips for UK Boiler Owners

Keep this guide handy for the next time your boiler stops giving hot water. Regular boiler servicing can also stop any of these issues arising to keep your boiler running efficiently and breakdown free.