Intergas Boiler Fault Code 12
The Intergas fault code 12 relates to the heat exchanger or S1 sensor and here we have Q & A. We could also offer you a service by you clicking on our emergency boiler repair booking.
The Intergas Boiler Fault Code 12 Error Common Q & A
Just below, we have a list of common questions relating to the fault code 12 on the Intergas Boiler.
- What does fault code 12 mean on my Intergas boiler?
- Can I get my boiler working temporarily until a boiler repair company can fix it?
- What will my boiler engineer be looking for when they come to fix my boiler?
- How can my boiler repair company determine if it’s the S1 sensor that has caused fault code 12 to be displayed?
- The sensor is fine, so, what other electronics need to be tested?
- If my PCB has failed, how much is a new one going to cost?
- What could have caused my PCB to fail in the first place?
- How could a circulation fault occur in my boiler?
- If limescale is blocking my heat exchanger, is there anything my boiler engineer can do?
- Are there any other preventative measures we can put in place to stop the 12 fault code occurring again?
What does fault code 12 mean on my Intergas boiler
If your boiler is showing a fault code on the display panel, it’s an indication of a problem. On most occasions, that’s going to lead to what’s known as a boiler lockout; the boiler won’t work.
Fault code 12 on Intergas boilers is similar to fault code 10, 11, 13 and 14. The problem here relates to the S1 sensor on the heat exchanger, the readings the printed circuit board (PCB) is being given, or a circulation issue within the boiler.
Can I get my boiler working temporarily until a boiler repair company can fix it
You shouldn’t attempt to get your boiler working. When fault codes are displayed on the control panel, it means there’s either:
- A problem that could lead to further expensive boiler repairs, as additional parts could get damaged
- A problem that could lead to the boiler being dangerous.
And, that’s why you should get in touch with a Gas Safe boiler repair company as soon as possible.
Once they’ve diagnosed the root cause of fault code 12 being displayed, they’ll be able to fix the problem. After fixing the issue, a reset will clear the fault code from the display panel, and your boiler should jump out of the lockout procedure to work as normal.
What will my boiler engineer be looking for when they come to fix my boiler
As the most likely cause of fault code 12 being displayed is an S1 sensor issue, this is where your boiler engineer is going to start.
But, the S1 sensor isn’t the only possible reason fault code 12 is being displayed.
Other things your boiler engineer is likely to check include:
- All electrical systems, including wires, connections and the PCB
- A circulation fault in the heat exchanger.
How can my boiler repair company determine if it’s the S1 sensor that has caused fault code 12 to be displayed
The PCB wants to see signals from the S1 sensor that the flow and temperature of water leaving the heat exchanger is within the correct range. When it isn’t getting this reading, it’s going to lockout the boiler and show a fault code, like the 12 fault code you’re seeing currently.
But they’ll need to determine if the S1 sensor is faulty, or, if the reading is correct and there’s another issue at hand (a circulation issue, for instance).
To check the S1 sensor, they’ll want to use a digital multi-meter. This will determine if the S1 sensor is getting power, and able to give the correct signals to the PCB. If power isn’t present, the cause of fault code 12 being displayed is a faulty sensor, and that’s going to need to be fixed.
The sensor is fine, so, what other electronics need to be tested
Ruling out the S1 sensor as the issue, your boiler engineer will need to continue testing using their multi-meter. Something as small as a loose connection or section of damaged wiring could be enough to mean the S1 sensor can’t give readings to the PCB, or the PCB can’t receive them.
If your boiler repair company notices no power at any point in the circuit, the connection, wires or component will need to be replaced to fix the problem.
Your Gas Safe engineer is going to want to focus their attention on the PCB. It’s the PCB that monitors all sensors in your boiler. So, if the PCB is faulty, it might be recommending the S1 sensor needs replacing due to lack of communication, but it could be the PCB at fault, not the sensor.
Like wires and connections, your boiler repair specialist will be able to test the PCB using a multi-meter.
If my PCB has failed, how much is a new one going to cost
Being one of the most important parts in your boiler, the PCB is also one of the most expensive. Expected prices for a replacement would sit in the region of £400-500. And, that means if your boiler is extremely old or in poor condition, your heating company might suggest getting quotes for a new one. After all, it makes no sense to invest this kind of cash into a deteriorating boiler.
What could have caused my PCB to fail in the first place
If the problem is the PCB and the economical option is a replacement, consider first, why it failed in the first place.
Whilst old age is a killer of internal boiler components, another common killer is water damage. And, that’s going to mean that to give your boiler longevity, you’ll need to do more than fix/replace the PCB.
First, your boiler repair company will need to locate the part that’s leaking. As an example, pump’s on boilers are prone to leaking, exposing expensive internal electrical components to moisture. Without fixing the pump’s seal, the problem is likely to occur again.
But, another common cause of leaks is a crack in the heat exchanger. These cracks usually develop due to limescale build-up. They create blockages and a high pressure environment, not to mention hot spots which help to weaken the heat exchanger.
Given fault code 12 relates to sensing issues within the heat exchanger, it’s a likely possibility that the heat exchanger is the cause of the blockage in your boiler in the first place. If the heat exchanger needs to be replaced, the cost could be over £400.
How could a circulation fault occur in my boiler
With fault code 12, it’s not always the sensor that’s the issue. The issue could be, the readings it’s giving are correct, but not within tolerance, so, the boiler’s PCB shuts the appliance down with a lockout.
As we’ve already mentioned above, limescale build-up in the heat exchanger could be the reason for the circulation fault, and the reason the sensor’s readings aren’t within tolerance.
Limescale build-up is most common in old boilers, especially in properties that reside in hard water areas. Harder water means there’s more ppm in the water in that area, and therefore, there’s lots more limescale.
The initial build-up of limescale can take years. But it has a snowball effect. The bigger the blockage is, the quicker it grows.
If limescale is blocking my heat exchanger, is there anything my boiler engineer can do
First, your boiler repair company needs to determine if the boiler is leaking via the heat exchanger. That’s going to lead to a replacement heat exchanger being needed, and they can cost upwards of £400.
If the heat exchanger has been caught in time, the limescale can be removed manually. But, to ensure the system is free from limescale to prevent this happening again, a hot flush using descaler can be completed.
After the descaling process is complete, your boiler repair company will dose the system with heating inhibitor. This helps to breakdown limescale before it manages to attach itself to any important boiler components. Then, they’ll want to fit a limescale filter. This filter is designed to catch any particles that the inhibitor breaks down.
Are there any other preventative measures we can put in place to stop the 12 fault code occurring again
When your emergency heating repair company takes apart your boiler, they might notice signs of heating sludge. This is rust that comes from pipework as well as radiators and will contribute to a blockage.
The hot flush mentioned above is going to help remove most of the heating sludge. And, the central heating inhibitor will break down any sludge that circulates in the system in future. Alongside a limescale filter, your boiler engineer can fit a magnetic system filter; specifically designed to catch heating sludge.
Other Intergas boiler issues
For more boiler issues regarding the Intergas boiler then please visit the Intergas Boiler Problems And Cures page.