7 Troubleshooting Tips for No Hot Water

Woman showering with no hot water

7 Troubleshooting Tops For No Hot Water


There is nothing worse than wanting to take a nice hot shower but when you turn on the mixer tap, there is no hot water. This can be really frustrating but it might just be something simple that is causing this issue. ​​A boiler is supposed to provide hot water for your home.

No one likes dealing with a boiler that isn’t providing you with hot water but by taking some troubleshooting steps, you might be able to fix the problem yourself.Let’s dive in and find out why your boiler isn’t providing your taps with hot water.

The first thing you need to do when your boiler has no hot water is to identify the problem. There are a few possibilities as to what might be causing the issue. Here we go!

Troubleshooting A Boiler With No Hot Water

1: It could be that the boiler is not working properly. This could be due to a variety of reasons, such as a power outage, a tripped circuit breaker, or a blown fuse. If the boiler is the problem, you will need to call a gas safe registered engineer to come and take a look at it.

If it is only a fuse that has blown which has caused the power to the boiler to switch off, this is something that can be done by a competent person. If you do not feel comfortable with trying to replace the fuse yourself, contact a professional.

All that you would need to do is to turn off the main electrical board then remove the fuse at the spur next to the boiler. It needs to be replaced with a 3 amp fuse. Once you have replaced it, turn on the mains power again and then switch on the power to the boiler then it should light up and provide you with hot water.


Low Water Pressure Causing No Hot Water

2: Another possibility is that there is a problem with low water pressure which could cause your to have no hot water. In this event you could most likely fix the problem yourself by topping up the pressure. Sometimes the pressure might drop in a heating system and it might only need topping up. If you are unsure on how to do this, please read one of our previous blog posts on this topic, it explains exactly how you would do this. Click How to top up your boiler pressure to read the blog post.


Picture of a guage showing low water pressure pressure | Letsgo TNT Gas & Heating Engineers



Faulty Programmer Causing No Hot Water

3: If your boiler is connected to a programmer that has the option to set the hot water to come on at various times, you might want to check to see if it has been set for the correct time. Sometimes only scheduling the boiler to come on to heat the hot water for 30 minutes might not be enough. Another possibility could be that the batteries are dead! In this case, you would see a battery symbol flash on/off. All you would most likely need to do in this case would be to replace the batteries.


A Faulty Diverter Valve Causing No Hot Water

4: ​A faulty diverter valve can cause a lot of problems in your home, in particular, no hot water. This is because the diverter valve is responsible for controlling the flow of water from your home’s main water supply to your taps, showerheads, as well as radiators. When the diverter valve is not working properly, it can cause a variety of problems, including low water pressure, leaks, and even flooding.

For example when you create a demand at the hot water tap, the boiler sends a signal to open the diverter valve in the hot water position. However, if the diverter valve sticks in the heating position, this could cause you to get no hot water from the taps.

How do you fix this issue? You will need to call a gas safe registered engineer to come out and either replace the valve or possible take it out and be able to clean it to stop it from sticking.If the valve dasing was cracked, it would need to be replaced.


sticking diverter valve inside a gas boiler

Is There A Water Leak Causing No Hot Water

5: If your heating system has a leak that is not visible, ie under the floor then you would not notice this. However what you would notice is the pressure guage on the boiler that keeps dropping. Remember, you can top up the pressure and it will cause the boiler to work again but it could potentially cause water damage if left unattended.

If you find that you need to top up the boiler pressure regularly, this is a telltale sign that you have a bigger leak that needs attention. In this instance you should call a professional heating engineer to come and investigate wherer the leak is coming from. If it is upstairs, you would most likely see wet patched coming through the ceiling. However, it it’s under the floor, this can be more challenging to find, particularly if the floor is concrete.


A Frozen Condensate Pipe

6: New condensing boilers differ slightly to older ones as much as they have what is called a condensate pipe coming out of the bottom of the boiler that goes into a drain. When the drain gets blocked either by debris in the sink waste in which it is connected to, this could cause the boiler to shut down and cause it to give you no hot water.

In this instance, you could remove the sink waste pipes and clean them out or leave it to a professional to do. Another issue that can cause the condensate pipe to block is through freezing in the winter months. If the pipe is installed to an outside drain but isnt the correct size and insulated, this can often be the cause of the pipe to freeze. Here is some extra information on how to fix a freezing condensate pipe. Click here.

You do not need to panic as this can be dealt with by yourself. Take a jug of hot water from the kettle, not boiling and pour it over the condensate pipe that exits through the external wall. Do this for a couple of minutes then see if the boiler will reset.

If this doesn’t work then you will need to conact a gas safe engineer to come out a fix it.


Is The water Supply Good?

7:  This might not seem to be an obvious candidate for causing no hot water but you should check to see if the mains water line is being worked on and has been turned off by the water company. All you would need to do here is open the cold tap to see if any water is coming out. If there is no water coming out, you should contact your water company and ask them why the mains water is turned off.



As you can see, it is not all doom and gloom if there is no hot water coming out of your taps. Sometimes it is a simple fix such as replacing the batteries on your programmer or pouring hot water over a frozen condensate pipe. The main thing you should take from this blog post is not to panic. If you are not able to fix the issue yourself, contact a local and compenent gas engineer that is gas safe registered.

We hope that you got some value from this blog post and share it with friends and family.If you need to call out a professional, contact us now!

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