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20 Common Boiler Problems: Boiler Repair San Diego

20 Common Boiler Problems: Boiler Repair San Diego

Boilers have a long life expectancy, anywhere between 10 to 15 years. However, that doesn’t mean that you won’t experience some issues during this time. If the boiler’s functionality has been compromised, the flow of hot water could be disrupted, which is a major inconvenience for any family. Apart from that, some malfunctions could even prove to be dangerous to the homeowners. A sure way to prevent this from happening is to schedule regular checkups with a professional company specializing in boiler repair in San Diego, such as PCE. Our experts have listed 20 most common boiler problems and advice on how to proceed with fixing them.

Pilot light is off

If your boiler is not working, the first thing you should check is whether the pilot light is on and that everything is alright with the power supply. If the boiler is plugged in, check the circuit breaker switch.


If you notice large amounts of water around the boiler, there is likely a leak. Leaky boilers lead to wasted water and increased fuel consumption. Furthermore, a leak can stress your boiler since it has to make up for the lost water by heating more cold water.

Cold or Inconsistent Water temperature

Perpetually cold water in the shower is a clear indicator of a malfunctioning boiler. Believe it or not, if the water is too hot, this can also signify an issue with the boiler unit. Whether it is too hot or too cold, inconsistent water temperature is often a sign of malfunction. A likely cause for the lack of hot water could be a malfunction in the heating element, while excessive temperatures can be caused by a faulty thermostat.

Metallic Odor/Taste

Another common, but not that dangerous issue is a metallic odor or taste in the heated water. If the water coming from the faucet is rusty, the problem can be either your pipes or your boiler.

Oil/Gas Odor

Any unusual smells can be a sign of serious trouble. In case you feel an unpleasant oil or gas odor, open the windows near your boiler, turn off the control valve and leave your house. This issue is best solved by contacting an emergency boiler repair service and not on your own, because of potential carbon monoxide poisoning. That is why it is always a good idea to install a carbon monoxide monitor if your home appliances are fueled by natural gas. If the alarm goes off, evacuate your home and seek professional help.

Increased Sediment

Another sign of a malfunction is when the water comes out muddy or with a higher mineral sediment concentration. Contacting a professional to check the contents of your boiler is the best course of action. However, if you prefer to do it on your own, make sure to disconnect the power and gas supply and then attach a hose to drain the water out.


If you hear a hissing sound coming from the boiler unit, the reason might be uneven water distribution. This occurs as a result of iron or sludge deposits, which can cause the system to overheat and even stop working completely. A popping or a cracking sound could mean that there is an increased mineral deposit concentration in the boiler, preventing the heating element from functioning properly.

Water Pressure

Hot water not flowing at the same pressure as cold water might be caused by scale build-up in the pipes or in the boiler unit. Another likely cause is a clog in the water line or a half-open valve.

Frozen condensate pipe

The condensate pipe serves to expel acidic water created by waste gas. Since this pipe goes outside and into the drain, if tends to freeze during winter. If the condensate pipe is frozen, you will be able to tell simply by looking at it. Some boilers display a warning when this pipe freezes. There are several ways you could fix this issue, but if you don’t feel confident in your skills better contact a professional.

Thermostat Issues

The thermostat is the most common element of the boiler to malfunction. If the thermostat is not displaying the correct temperature or is turning the heat on and off when it shouldn’t, you might want to replace it. Although it might be possible that the thermostat is not set properly or that you might have misjudged your home temperature, it also might be possible that the thermostat has failed due to years of use.


Sometimes a strange sound resembling a boiling kettle can come out of the boiler. This often happens when scale or sludge build up inside the heat exchanger. Deposited sludge can reduce the flow of water in the heat exchanger, overheating the water and causing it to boil. This often happens with locations that have hard water, but not necessarily. This issue can significantly impact your energy bill and shorten the boiler’s lifespan.

Boiler keeps switching off

If your boiler keeps switching off, there might be an issue with water pressure, the thermostat or lack of water flow. The safest way to identify what’s causing the boiler to malfunction is to contact a professional.


If there are signs of rusting on your boiler contact an expert immediately as rust is the primary cause of boiler breakdown. The rusted areas can be covered up with a patch as a temporary solution, but a replacement will likely be required.

Chimney Liner

Prolonged use and high temperatures can result in a falling chimney liner, damaging anything in the boiler’s vicinity.

Pump Bearings

If you notice a grinding sound as soon as your boiler becomes operational, you could be experiencing bad bearings in the water pump. This can severely damage or destroy the pump and will require a prompt replacement. Unfortunately, if your boiler unit is an old one, you might have some trouble finding an adequate replacement and may have to purchase a new boiler altogether.

Boiler starts, flame goes out soon

A likely cause for this is flue blockage. Check for any signs of a blockage as well as dilution fan operation. Another possible cause is a failure of the circuit in charge of low-pressure hot water.

Boiler overheats

If your boiler is overheating, check the voltage, safety switches and temperature settings because a likely cause of overheating is a failure in the system controls. The problem could also lie with the high-limit thermostat being activated as a result of control thermostat failure.

Fumes in the boiler room

One potential cause for fumes in the boiler room could be inadequate combustion airflow. In this case the system should be checked for any blockages. Additionally, the fans in the boiler room might have malfunctioned. Another likely reason within the system itself could be unsealed test holes in the flue or a leaky flue.

Boiler fails to meet system load

A likely reason for this is that the thermostat is improperly set, in which case you should check the settings. Another reason could be poor combustion, in which case you should check the flame, flue and combustion quality.

Boiler does not ignite

Finally, if the boiler does not ignite you could be facing several issues. First, check for any signs of internal controls failure, and reset or replace them. The boiler might have overheated and the overheat cut-out did not reset. Another likely possibility is that the supply fuse might have blown out. The boiler heat might not have pilot flame, in which case check for incorrectly installed nozzle, or insufficient gas to the pilot. Additionally, if the pilot flame does ignite but fails immediately, check the flame detector voltage. If the thermocouple voltage is low, you should replace it.

If the burner does not light, look for fuel leaks. And if all above fails, check if the ignition spark is present. If not, there could be several reasons such as short circuiting, carbon deposits, and excessive electrode gap, among others.

Professional Boiler Repair San Diego

You can always count on PCE to properly inspect, repair or replace your boiler in case of a suspected malfunction. Ask our friendly technicians about the regular maintenance service and rest assured your boiler will serve you well for a long time.
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