Biasi Boiler ER02 Fault Code
The Biasi fault code ER02 related to the overheating which we include Q & A or require an engineer for an emergency boiler repair.
The Biasi Fault Code ER02 Error Common Q & A
Just below, we have a list of common questions relating to the ER02 fault code on the Biasi Boiler.
- What does the ER02 fault code mean on my Biasi boiler?
- Is there a DIY fix for the ER02 fault code?
- What could have caused the ER02 fault to develop in the first place?
- The safety thermostat isn’t the problem, what else should my boiler repair company check?
- What is a condensate pipe, and how could a blockage affect my boiler?
- If the condensate pipe is causing the problem, how can the problem be fixed?
- Why would the pump cause issues that lead to the ER02 fault code being displayed?
- What problems are likely to be restricting the pump’s circulation?
- What is heating sludge, and how can it affect the pump?
- How can my boiler repair company remove a sludge blockage, and prevent it from happening again?
- How will my boiler engineer know if the pump’s internals are worn?
- If I need a new heating pump, how much is it likely to cost?
- What are airlocks and how can they be removed?
- How could limescale cause an overheat in my boiler?
- If I need a new heat exchanger, how much is it likely to cost?
- Is there anything else that could cause the ER02 fault code to be displayed?
What does the ER02 fault code mean on my Biasi boiler
Once your Biasi boiler develops a problem, it’s going to show a fault code on the display panel. This helps a boiler engineer to quickly narrow down the problem, making the fix much quicker than it would be otherwise.
In the case of the ER02 fault, the safety thermostat is being activated on your boiler. This is going to kick into life when it notices that the boiler is overheating.
Is there a DIY fix for the ER02 fault code
Some faults can be fixed without an engineer’s help, but the ER02 fault code isn’t one of those faults. To fix this fault, the boiler’s casing is going to need to be removed, in order to access internal components.
Removing the boiler’s casing is classed as working on a gas appliance. To legally work on gas appliances, the person doing the work needs to be Gas Safe registered. So, you should call an engineer for help.
What could have caused the ER02 fault to develop in the first place
The first place to start, is the safety thermostat. If the safety thermostat is faulty, it could be activating early at too low a temperature, and therefore, communicating the wrong signals through to the printed circuit board (PCB).
Your boiler engineer will need to check the integrity of the thermostat. If the safety thermostat is faulty, it will need to be replaced. Once replaced, resetting the boiler will clear the ER02 fault code from the display panel.
The safety thermostat isn’t the problem, what else should my boiler repair company check
After ensuring that the thermostat is doing its job properly, the next thing to check is anything that could lead to the boiler overheating. This could include:
- Condensate blockages
- Pump problems
- Limescale issues
- Central heating sludge build-up
What is a condensate pipe, and how could a blockage affect my boiler
For safety, all waste gases need to be vented from your property. Normal gases are expelled via the flue, and condensed gases escape via the condensate pipe. In colder months, the condensate pipe is prone to freezing. This freeze over is what causes a blockage. Due to the heat of gases and lack of airflow, a blocked condensate pipe can cause a boiler to increase in temperature, and eventually, to overheat.
Even if the overheat isn’t the problem here, your boiler is going to lockout anyway. The PCB monitors all important components on your heating system, including the condensate pipe. Due to the fact the condensate pipe helps to keep your boiler safe, the second it’s blocked, your boiler is going to lockout.
If the condensate pipe is causing the problem, how can the problem be fixed
If the ER02 fault code is a result of a frozen condensate pipe, it’s likely the fix is simple; thaw out the condensate pipe and reset the boiler.
However, if this problem has occurred once, it’s likely to occur again. Speak to a Gas Safe boiler repair company, there may be something they can do to improve the external pipework on your property. It’s likely they can route the pipe closer to vertical, use a larger diameter pipe, and lag it.
All three of these actions combined, are going to reduce the risk of your condensate pipe freezing again in the future.
Why would the pump cause issues that lead to the ER02 fault code being displayed
After water is heated in your boiler, it’s the pump’s job to quickly circulate that water around the heating system. If it pumps water around your boiler slowly, water will lose temperature. The differential in temperature between the flow (water leaving the boiler) and return (water returning to be heated), is going to be too large; the appliance is going to overheat and lockout.
What problems are likely to be restricting the pump’s circulation
There are few things your boiler engineer is going to be looking out for, including:
- Heating sludge build-up
- Worn internals
- Airlocks
What is heating sludge, and how can it affect the pump
Heating sludge is a common in modern central heating systems. It’s rust that breaks off radiators, towel rails and pipework; and it can get lodged just about anywhere.
Assuming the sludge blockage is in the pump, this can be manually removed. However, if there’s a blockage in the pump, there’s likely to be a blockage elsewhere, so your boiler repair company needs to remove it, and protect your system from future blockages.
How can my boiler repair company remove a sludge blockage, and prevent it from happening again
The most common way to remove sludge from a heating system, is a hot flush. Essentially, this involves topping up the heating system with cleaning chemicals, leaving it running at a high temperature for a short period, and draining the water from the heating system (which in turn, drains any sludge).
Some engineers prefer to power flush; that’s a hot flush at higher pressures using a machine. However, on older systems, this might put old joints and components under too much pressure, causing a leak.
After performing a hot flush, your system can then be protected. It’s likely your boiler engineer is going to fit a magnetic system filter which is designed to catch heating sludge. For the filter to be able to catch it, the chunks of sludge need to be broken down into manageable pieces.
This is where central heating inhibitor comes in. Inhibitor is designed to be added to the heating system, breaking down any sludge particles into manageable chunks that the filter can catch and remove.
How will my boiler engineer know if the pump’s internals are worn
If the pump isn’t operating smoothly, it’s likely a replacement is going to be needed; it won’t be providing the level of circulation that’s necessary.
The parts they’ll need to check include the shaft and bearings. If both are worn, its likely old age is the culprit. However, this isn’t always the case. If the pump has been fitted so the shaft isn’t completely horizontal, then the shaft and bearings are going to wear out prematurely.
If I need a new heating pump, how much is it likely to cost
If you’re having a new heating pump installed, you’ll want a quality one from a brand such as Grundfos. Typically, we’d expect the cost of a replacement pump, including parts and labour, to be around £250; expect the job to take 1 working day to complete.
What are airlocks and how can they be removed
Airlocks are pockets of air that can get trapped in the heating system. Typically, they’re found in radiators. However, they can be found in heating pumps too. And, when they are, they can cause all sorts of problems; they act in the same way that a blockage would.
If an airlocked heating pump is the problem, the fix is simple. As we mentioned prior, the job needs to be completed by a Gas Safe boiler repair company. What they’ll do, is remove the boiler’s casing to expose the pump.
They’ll locate the bleed screw and they’ll be able to bleed air from there. Once the air has been bled from the pump, the boiler can be reset to clear the ER02 fault code.
How could limescale cause an overheat in my boiler
Limescale can work in a similar way to heating sludge; it attaches itself to parts, and by doing so, can cause blockages. Ultimately, this affects the circulation of water and can easily cause your appliance to overheat.
Limescale doesn’t come from rust; it’s minerals that are contained in heating water. They can settle just about anywhere, including the pump mentioned above. However, another common place they can settle is the heat exchanger plate.
Your boiler relies on consistent heat transfer from the heat exchanger. Unfortunately, limescale build-up on the heat exchanger can lead to certain parts of the exchanger plate being hotter than others.
This causes two problems. First, water temperature can spike, causing the boiler’s water to overheat. Second, the increased temperatures can cause the heat exchanger to crack; that’s going to lead to a replacement being needed.
If I need a new heat exchanger, how much is it likely to cost
Unfortunately, heat exchangers are one of the most expensive parts on modern boilers. Typically, we’d expect a cost of £375-475, depending on the exact Biasi boiler you own.
With large repair bills like this, you need to seriously think about the overall condition of your boiler. New boilers can start at as little as £1800 with a long warranty. If yours is old, out of warranty, and constantly costing money, it might be a wiser investment to upgrade, rather than repair.
Is there anything else that could cause the ER02 fault code to be displayed
If none of the above provides a solution to the fault, your boiler repair company will need to check the PCB. The PCB is the most important component in your boiler, as it gives/receives signals to a range of components and sensors. So, if the PCB fails, it could be misinterpreting signals. For example, the safety thermostat might not be activated, but the PCB thinks it is.
Your boiler engineer can test the integrity of the PCB using a multi-meter to determine if this is the problem. If the PCB is faulty, it’s worth discussing with your engineer whether you should replace the PCB (at a cost of £400-500), or a better investment would be a new boiler with a long warranty.
Other Biasi boiler issues
For more boiler issues regarding the Biasi Boiler then please visit the Biasi Boiler Problems And Cures page.