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No Hot Water? Read Our Symptoms & Solutions

no hot water

Waking up in the morning and finding that there is no hot water can completely ruin your day. Unless you have an electric shower, you will have to suffer a cold shower in the morning. There are a number of reason why you may have no hot water and we aim to provide you with all the symptoms and solutions.

The Obvious Checks

Before ringing your local plumber and getting them over to check for faults, you should check the obvious to avoid being left red faced. Below are some basic troubleshooting checks you can do yourself:

  • Testing all taps to see if its an isolated problem – Is it all the taps?
  • Check the electricity supply – Was there a power cut?
  • Is the thermostat set high enough – Did someone change it?
  • Check to see if its a gas supply issue – Are the radiators working?
  • Is the weather freezing? – Checked outside for frozen pipes?

These are just basic checks and if they are all “as they should be” it may be time to look elsewhere.

no hot water but heating works

Checking The Boiler

If this is a common problem and you have been reluctant to service your boiler, we strongly recommend that you do so before it causes further problems. For those that are looking for a quick fix to no hot water, you may be able to get a way with simply resetting the boiler. This should be a simple reset switch and not one where you need to take the casing from the boiler in order to get to it.

Other checks include ensuring the thermostat is set correctly and checking the clock and timer is set to the right time. If you have a gas boiler as opposed to an electric combi boiler, you will also want to check the pilot light is alight otherwise the gas will not be able to ignite without it. If this is the case, the thermocouple may need replacing and for this, you would need a heating engineer to perform the replacement.

For those with a combi boiler, you may want to check that there is enough pressure. The usual amount of pressure required is at least 1 bar but this does vary slightly between different boiler brands. If its below what is recommended by your boiler brand (check the manual), then simply increase the pressure. There will usually be a valve below the boiler to do this.

No Hot Water But Heating Works

If you have touched the radiators and they are nice and warm, this would mean that you have no hot water but the heating is still working. This will point the finger straight at the diverter valve, which allows the combi boiler to switch between heating your radiators and water. This will need to be replaced by a professional but you could try reseting the boiler with the hope of it fixing the problem with the diverter valve.


Our team of plumbers in Cardiff receive calls on a daily basis with the customer having a problem with no hot water. Hopefully, this guide will help you troubleshoot some basics and allow you to fix the problem yourself. We could go into further detail with regards to no hot water but to the average person, this may not be of any use!

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180 Ffordd James McGhan, Cardiff, CF11 7JU
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