Boiler Not Heating Water (Even Boiler Runs)! Here’s What to Do

A boiler is a pressurized system that converts water into steam by heating it to its boiling point. The steam is then transported through pipes to various parts of the house where it can be used for heating, powering appliances, or providing hot water. 

The boiler itself is a tank that holds water. The tank is then heated by either burning natural gas or oil or by using electricity. The heat from the fuel source boils the water in the tank, and the steam that is produced is forced up into the pipes.

The steam that is produced is then used to heat the house or to power appliances. The steam can also be used to provide hot water. The hot water from the boiler can be used for cooking, washing, or bathing.

Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated to steam have many uses.

The problem is that when a boiler doesn’t work properly or can’t heat the water within your desired time, it is a reason for annoyance for you. There are many reasons why your boiler is not heating water.

The Process of Water Heating

Domestic water heating represents a significant proportion of household energy use, especially in colder countries. In most houses in the United States, gas-fired boilers are used for water heating. Often, these boilers are fitted with a device called a “tankless coil” to heat water on demand.

Water heating is normally accomplished by one of three methods:

Immersion heating, in which a heating element is inserted into the water

Convection heating, in which water is heated as it circulates through a heating element

Radiator heating, in which water is heated by circulating it through a radiator

The most common method of domestic water heating is immersion heating. This involves inserting a heating element into the water, which then heats the water. The advantage of immersion heating is that it is very efficient, and can be used with various energy sources, including electricity, gas, and oil.

Convection heating is another common method of water heating. In this method, water is heated as it circulates through a heating element. This type of heating is very efficient and can be used with various energy sources.

Radiator heating is the third most common method of water heating. In this method, water is heated by circulating it through a radiator. Radiator heating is not as efficient as the other two methods, but it has the advantage of being able to use a variety of energy sources, including coal, wood, and oil.

Boiler Not Heating Water

Pilot Light Problems

If your boiler’s pilot light is out, then the boiler will not be able to heat up the water. In order to fix this, you will need to relight the pilot light. If you are not sure how to do this, then you should consult your boiler’s instructions manual.

If your boiler’s pilot light is out, then the water in your boiler is not being heated. There are a few reasons why this may be happening, and there are a few ways to fix it.

One reason why your boiler’s pilot light may have gone out is that there is a draft in the room where your boiler is located. If there is a draft, then the pilot light can be blown out easily. To fix this, you can try to block the draft by putting a towel under the door or by closing a window.

Another reason why your boiler’s pilot light may have gone out is that the gas valve is not turned on. The gas valve is what supplies the gas to the pilot light, so if it is not turned on, then the pilot light will go out. To fix this, you can simply turn on the gas valve.

If neither of these solutions works, then you may need to call a professional to come and take a look at your boiler.

Thermostat Issues

There are several possible reasons why your boiler does not heat the water. The most common reason is that the thermostat is not set properly. The thermostat controls the water temperature in the boiler, so if it is set too low, the water will not heat up properly. 

Your boiler’s thermostat is one of the most important components in keeping your boiler running smoothly and keeping your home warm. If your thermostat is not working correctly, it can cause your boiler to overheat or not heat the water properly. There are a few things that you can do to fix this problem.

The first thing that you should do is check the batteries in your thermostat. If the batteries are dead, they will not be able to send the correct signal to your boiler telling it to turn on or off. You should also check the wiring to your thermostat to make sure that it is not loose or damaged.

If the batteries and wiring are fine, the next thing you should check is the settings on your thermostat. Make sure that the thermostat is set to the correct temperature for your home. If it is not, it will not be able to send the correct signal to your boiler telling it when to turn on or off.

If you have checked the batteries, wiring, and settings on your thermostat and it still is not working correctly, you may need to replace the thermostat. You can purchase a new thermostat at most hardware stores. Once you have replaced the thermostat, you should be able to enjoy the warm water in your home again.

Sediment Build-up

If your boiler isn’t heating water, one of the most common reasons is sediment build-up. Over time, minerals in the water can settle in the bottom of the boiler and create a layer of sediment. This can insulate the heating element and prevent it from transferring heat to the water.

There are a few ways to clean out the sediment and get your boiler heating water again. One method is to drain the boiler and refill it with fresh water. This will flush out the sediment and allow the heating element to work properly again.

Another method is to use a boiler cleaning solution. These solutions are designed to break down the sediment and allow it to be flushed out of the boiler. Be sure to follow the instructions on the cleaner carefully, as using too much or leaving it in for too long can damage the boiler.

If you’re still having trouble after trying these methods, it’s possible that the heating element itself is damaged and will need to be replaced. A qualified technician can diagnose the problem and make the necessary repairs.

Frozen Pipes

If your boiler isn’t heating water, it could be because of frozen pipes. Frozen pipes can happen for a number of reasons, such as when the temperature outside drops suddenly or if there’s a problem with the heating system.

 If your pipes are frozen, you’ll need to thaw them out before the water can start flowing again. There are a few ways to thaw out frozen pipes. One is to use a hairdryer. Just turn it on and aim it at the pipe until the ice melts. You can also use a heat lamp or an infrared heater. 

Another option is to pour hot water over the pipe. Start by heating up some water on the stove and then pour it over the frozen pipe. You may need to do this a few times before the ice melts. Once the ice is melted, you should be able to turn on your boiler and the water should start flowing again. 

If the water doesn’t start flowing right away, there may be another problem with your boiler. If you’re not sure what the problem is, it’s best to call a plumber or heating technician to take a look.

Gas Supply, Water, or Electrical Issues

When your boiler is not heating water, there can be a few reasons why. It could be an issue with the gas supply, the electrical components, or the water itself.

If it’s a gas supply issue, the first thing you’ll want to do is check the pilot light. If it’s out, relight it following the instructions in your boiler’s manual. If the pilot light won’t stay lit, there may be a problem with the gas line or the pressure regulator. If you suspect a gas line problem, call your gas company. If the pressure regulator is the issue, you’ll need to replace it.

If the problem is with the electrical components, first check the circuit breaker or fuse box. If the breaker has tripped or a fuse has blown, reset it or replace the fuse. If that doesn’t solve the problem, there may be an issue with the wiring. If you’re not comfortable working with electrical wiring, call an electrician.

The water itself could also be the issue. If the water is too cold, the boiler won’t be able to heat it. This is most likely the case if the boiler has been turned off for a long period of time. To fix this, simply turn on the boiler and wait for the water to warm up.

If you’ve checked all of these things and the boiler still isn’t heating water, it’s time to call a professional.

Read More: The Dangers of a Boiler Gas Leak! How to Prevent It?

Diverter Valve Defective

If your boiler isn’t heating water, it could be because of the diverter valve. The diverter valve is responsible for directing water to the heat exchanger. If the diverter valve is defective, water won’t be able to flow to the heat exchanger and your boiler won’t be able to heat the water.

To fix a defective diverter valve, you’ll need to replace it. You can do this yourself if you’re handy with tools, or you can hire a professional. Replacing the diverter valve is a relatively simple process and shouldn’t take more than a few hours.

Once you’ve replaced the diverter valve, your boiler should be able to heat water properly. If you’re still having problems, it could be because of another issue, such as a faulty thermostat or a clogged water filter.

Pressure Issues

If your boiler is a combi then you will notice a pressure gauge in the green zone. If the boiler pressure is too high or too low, it will not be in the green zone, so you will not get hot water from your boiler. So your pressure should be checked.

In this case, you can solve the problem by following the instructions in the boiler manual. If you need to increase or decrease the pressure, you will find instructions on how to adjust the gauge from the red zone to the green zone.

Bleeding your radiators is the best place to start if the pressure is too high. This will help relieve pressure.

Also, you may have the thermostat could be set too low. The thermostat controls how hot the water gets, so if it’s set too low, the water won’t get hot enough. You can adjust the thermostat by turning it up a little bit at a time until the water is hot enough for you.

If neither of these solutions works, then there could be something wrong with the actual boiler. In this case, you’ll need to call a plumber to come and take a look at it.

Boiler Runs but No Hot Water

If your boiler is running but not heating water, there are a few possible reasons why. Below, we’ll go over some of the most common reasons for this problem and what you can do to fix it.

1. Loss of water pressure. If your boiler’s water pressure is too low, it won’t be able to heat the water properly. You can check your boiler’s water pressure by looking at the pressure gauge on the front of the boiler. If the needle is below 1, you’ll need to add water to the boiler to bring the pressure up.

2. Problem with the thermostat. If the thermostat is set too low, it won’t allow the boiler to get hot enough to heat the water. You can check the thermostat by opening the cover and looking at the setting. If it’s set below 60 degrees, you’ll need to raise it.

3. Dirty burner. If the burner is dirty, it won’t be able to heat the water properly. You can clean the burner by removing the burner assembly and scrubbing it with a wire brush.

4. Clogged air filter. If the air filter is clogged, it won’t allow enough air to reach the burner. You can clean the air filter by removing it and scrubbing it with a wire brush.

5. Problem with the igniter. If the igniter is dirty or damaged, it won’t be able to ignite the gas. You can clean the igniter by removing it and scrubbing it with a wire brush.

6. Problem with the gas valve. If the gas valve is damaged or stuck, it won’t be able to supply gas to the burner. You can replace the gas valve by removing the old one and screwing in a new one.

7. Problem with the pilot light. If the pilot light is out, the boiler won’t be able to ignite the gas. You can relight the pilot light by following the instructions in the owner’s manual.

8. Problem with the thermostat switch. If the thermostat switch is damaged or stuck, it won’t be able to turn on the boiler. You can replace the thermostat switch by removing the old one and screwing in a new one.

9. Problem with the circuit breaker. If the circuit breaker is tripped, the boiler won’t be able to get power. You can reset the circuit breaker by flipping it to the “Off” position and then back to the “On” position.

10. Problem with the heating element. If the heating element is damaged, it won’t be able to heat the water. You can replace the heating element by removing the old one and screwing in a new one.

Final Words

If your boiler isn’t heating water, there are also more potential causes. The most common causes are a broken heating element, a failed thermostat, or a tripped circuit breaker. If your boiler has a broken heating element, you’ll need to replace it. If your boiler’s thermostat has failed, you’ll need to replace it. If your boiler’s circuit breaker has tripped, you’ll need to reset it.

If your boiler is too old, it will lose its efficiency over time. In that case, you should maintain it regularly or think of a new boiler. Because the older the boiler, the greater the risk of accidents.