Biasi Boiler Fault Problems And Cures

The Biasi boiler faults, problems and cures Q & A or require an engineer for an emergency boiler repair.

The Biasi Boiler Faults, Problems And Cures Common Q & A

This article is going to cover some of the most common Biasi fault codes, the reason that causes them to be displayed, and the cures to get them fixed as soon as possible.

If you’re constantly having problems with your Biasi boiler, this guide is going to help you determine what needs to be fixed, the costs involved, and whether it’s worth considering installing a new appliance.

Your Biasi boiler is controlled by a component called a printed circuit board (PCB). It’s the PCB that communicates with all components to tell them when to kick into life, and when they’re no longer needed. This includes the likes of the gas valve, burner and even the pump.

Alongside functional components such as the pump, it also monitors a range of sensors. For instance, it monitors air pressure, water pressure and water temperatures. The readings the PCB receives from these sensors indicates whether the boiler is working within tolerance.

When the boiler isn’t working within tolerances and the PCB recognises that there’s a fault, it’s going to display a fault code on the display panel. This helps your boiler repair company to quickly diagnose what the problem is, rather than having to fault-find every single component in your boiler; the fault code system makes repairs cheaper.

The lockout function has another role; it ensures your boiler is safe. For instance, if the PCB recognises the gas pressure is too low or high, it locks out, as a gas fault could be dangerous.

For this reason, you shouldn’t try to reset your boiler. Instead, call a Gas Safe boiler company to diagnose the fault, fix it, and they’ll then reset your boiler on your behalf.

Biasi Fault Codes

Here are the most common Biasi fault codes that we come across, all of which have been explained below: (Please note, all these codes are clickable into further articles relating to each code).

Vaillant Boiler F22 Fault Code Error

If the ER01 fault code is being displayed on my boiler, what does it mean

The ER01 fault code on Biasi boilers relates to an ignition problem. Being ignition related, there’s a chance the boiler could be dangerous if it continued to operate. So, your boiler is going to lockout and shouldn’t be reset until the problem is fixed.

After calling a Gas Safe engineer, it’s likely they’ll start by checking things like the:

  • Condensate pipe for blockages
  • Pressure from the meter, and into the boiler
  • Issues that hinder the gas valve’s operation
  • Fan’s ability to provide a large enough draft, taking harmful flue gases up the flue
  • Burner for blockages

Condensate pipe blockages are common during winter; condensed gases in the pipe are prone to freezing. This is one of the simplest ignition related issues to fix. All your engineer will need to do is gently thaw out the pipe, and then reset your boiler. They’ll also want to check the fan, as if this isn’t operating correctly, the flue will be another airway that isn’t venting.

However, things relating to gas pressure can be a little more complex. The regulator on the meter could be blocked, or the gas pipework may not be to current regulations; this may mean that upgraded pipework is needed.

If gas pressure is high enough but the boiler’s starved of gas, it’s likely they’ll look at the gas valve. It’s the gas valve that provides fuel to the burner. If this is blocked, stuck or faulty, the boiler won’t operate efficiently.

Sometimes, a gas valve can be freed. Where this isn’t the case, your engineer is going to suggest a replacement. Typically, we’d expect a gas valve replacement to cost around £250-300.

Finally, your boiler repair company will check the burner is clear of debris. If this isn’t burning efficiently, the PCB is going to shut your boiler down. On some occasions, it’s a simple case of cleaning out the pilot jet; even the smallest amount of debris could block this jet and stop the boiler from working efficiently.


What does it mean if the ER02 fault code is being displayed on my Biasi boiler

Another common fault we come across with Biasi boilers is the ER02 fault code. This error relates to the safety thermostat kicking in, due to the boiler overheating.

The possible reasons for this happening are endless. However, your boiler engineer needs to start by checking the safety thermostat is working correctly.

Using a multi-meter, they’ll be able to test the safety thermostat to ensure it’s getting power. If power is intermittent, the thermostat is damaged or wiring/connections are loose, it could be feeding the PCB the wrong signals. And, that could lead to the boiler locking out, even though it’s not overheating.

If the thermostat is in good condition, there are other things to check, including:

  • Blockages in the condensate pipe
  • Limescale build-up
  • Central heating sludge build-up.

The condensate pipe may have frozen over. If this is the case, your boiler repair company will need to thaw it out and reset the boiler to clear the ER02 fault code.

However, we find that limescale and central heating sludge are usually to blame. A build-up of both can cause the heat exchanger to quickly overheat. When water passes through the NTC thermistors monitoring water temperature, the boiler recognises that there’s a problem and locks out.

Alternatively, there could be a blockage in the pump. Alongside heating sludge and limescale, airlocks are a major problem.

These three things combined could mean that your boiler’s pump isn’t able to circulate water correctly. Like the heat exchanger issue above, that’s going to lead to water overheating and the PCB locking out the boiler to protect all important internal components.

My boiler is showing the ER03 fault code, what has caused this to be displayed

The ER03 fault code on Biasi boilers is one of the more complicated errors we come across. Most fault codes are extremely specific, meaning your Gas Safe repair company can quickly diagnose the issue, fix the problem, and reset your boiler.

However, in the case of the ER03 fault code, the problem is a “general lockout”. Essentially, almost any boiler fault could have caused the issue, which means it might take longer than usual for your emergency heating engineer to find and fix the fault.

What they can do, is start with the most obvious potential causes. If the problem hasn’t been highlighted specifically, they can test the PCB using a multi-meter. It might be that there’s an issue with the PCB which means it’s not able to detect the problem with 100% accuracy, hence the generic fault being displayed.

If there’s no problem with the PCB, your engineer will want to check your boiler’s pressure. A comfortable operating pressure for most boilers is around 1.3 bar. If the pressure is above or below this, this is where they need to start.

For low boiler pressure, it’s likely a leak has caused the drop in pressure; they’ll need to fix the leak before topping up boiler pressure. And, if boiler pressure is too high, it’s likely the filling loop is letting by, or the system has been overfilled in the past.

But not all problems relate to boiler pressure. There are several other things your boiler repair company will want to check, including the:

  • Operation of the fan
  • Condensate pipe; is it blocked?
  • Air pressure switch
  • Heating system for sludge or limescale blockages
  • Airlocks in radiators, towel rails, or the boiler’s pump

Unlike most fault codes that are much more specific, the fault-finding process here is a case of going through each component and determining whether it’s operational.

Can the problem causing the ER04 fault code to be displayed be fixed

The ER04 fault code is much more specific than ER03. ER04 relates to circulation, or lack of water/pressure in the heating system.

So, the first job for your engineer is to determine whether it’s circulation, or water pressure that’s the problem.

To do that, they’ll want to check the pressure gauge on your boiler. Typically, we’d expect the pressure gauge to be showing around 1.3 bar. If the boiler’s pressure gauge is sitting at 1-1.5 bar, it’s unlikely that this is the problem.

If the boiler pressure is lower than 0.5 bar, most appliances will lock out. Most likely, the drop in pressure has been caused by a leak. This could be something as simple as a leaking radiator valve.

As water escapes from the system over time, the pressure is going to drop. Eventually, the PCB recognises that components are going to be overworking to compensate for the loss of pressure. Rather than allowing these parts to overwork and wear out prematurely, the PCB shuts down the boiler and displays the fault code.

In this case, the boiler’s pressure needs to be returned to around 1.3 bar using the external filling loop, after the leak has been fixed. Then, a quick reset will clear the ER04 fault code from the display panel.

Whereby pressure isn’t the problem, your engineer needs to look at the pump’s ability to circulate water. It’s likely the pump is blocked with heating sludge, limescale, or airlocked.

Heating sludge and limescale can be removed using cleaning chemicals or a central heating power flush, and airlocks can be removed manually.

However, if the pump isn’t functional (for instance, the shaft’s bearings have worn out), it may need to be replaced. A typical replacement pump from a well known brand such as Grundfos, is going to cost in the region of £250, including parts and labour.

What can be done to clear the ER05 fault code on my Biasi boiler

The ER05 fault code is one that relates to the fan not working correctly. If your boiler hasn’t locked out, we’d suggest turning it off until you’re able to get a Gas Safe engineer to come and help you.

The fan on your boiler plays an incredibly important role, in terms of safety. It creates a draft big enough to push harmful gases from your boiler, to the flue. The flue then pushes the flue gases out of your property.

So, if the fan isn’t working correctly, your boiler could be filling with harmful gases. As soon as this happens, your PCB recognises that the boiler is dangerous, and locks it out. Do not attempt to reset it.

The questions your boiler repair engineer needs to be asking include:

  • Is the fan speed too low?
    • Increasing the fan speed will create a stronger draft, pushing these gases where they should be going
  • Are all connections and wires in good condition?
    • Poor electrical connections and wiring could lead to intermittent signals from the PCB; the fan might not be getting the commands it should, when it should
  • Is the fan beyond repair?
    • On most occasions, it’s likely your boiler repair company will be able to fix the fan on your Biasi boiler. However, when this isn’t possible, you should expect to pay around £250-300 for a replacement

My Biasi boiler is showing the ER06 fault code, what does it mean, and can it be fixed

If your Biasi boiler is showing the ER06 fault code, it’s means there’s a problem with the central heating temperature probe.

There are two scenarios to consider here:

  • The central heating temperature probe is faulty
  • The probe is giving the correct reading, and something is leading to the water being extremely high in temperature for central heating

So, the first thing your boiler repair company will want to check, is that the probe isn’t broken. If it is, it could be feeding back incorrect readings to the PCB. The PCB is going to think that the boiler is working outside its tolerances (even when it’s not), and that’s going to lead to a lockout and the ER06 fault code being displayed.

Your boiler repair company will need to test the central heating temperature probe using a multi-meter. If there’s no (or intermittent) power, they’ll need to replace the probe and then reset your boiler to clear the ER06 fault code.

If the probe is giving the correct reading, they’ll need to check things like the:

  • Central heating pump
  • Radiators and towel rails for airlocks
  • Printed circuit board

In the case of the pump, it could be set to the wrong speed setting, or partially blocked with heating sludge. The speed setting can easily be adjusted, and heating sludge and/or limescale can be removed using chemicals.

But it’s worth considering the overall condition of the pump. If the shaft and bearings are worn, a replacement might be needed. Typically, we’d expect a replacement pump to cost around £250 including parts and labour.

Next, removing airlocks from the heating system is going to improve circulation. This can be done by using a radiator bleed key. After gently opening the valve, a hissing noise will occur; this is air escaping. Once the air is replaced by water dribbling from the radiator, that’s a sign that all air has been removed from that radiator/towel rail; move onto the next one.

Finally, your engineer will need to test the PCB with a multi-meter. If there’s a problem with the PCB, it’s not going to be communicating with, or receiving the correct signals, from the probe. In some circumstances, the PCB will need to be replaced.

Typical PCB replacement costs sit in the £400-500 range for Biasi boilers.

What does the ER07 fault code mean on my Biasi boiler

The ER07 fault code is similar in a way to the ER06 error. But, instead of the central heating temperature probe being the issue, as with ER06, the problem here is the with the direct hot water probe.

If multiple codes are showing, it may be that the problem is the linked to the ER07 fault and is causing problems with all temperature readings. Issues such as lack of circulation (pump problems, blockages and airlocks) and errors with the PCB could all be root causes of this.

However, the main thing your boiler engineer is going to be focusing on here, is the probe itself. They’ll want to test the probe using a multi-meter. By doing this, they’ll be able to determine whether the problem is the probe, wiring, or its connections.

If the probe is the problem, then it’s going to need to be replaced. However, if wiring is the issue, sometimes sections can be repaired. And, in the case of loose connections, securing them should reinstate communication with the PCB.

After resetting your boiler, the ER07 fault code should be cleared from the display panel.

My boiler is showing the ER14 fault code, how can this be fixed

To fix the ER14 error on Biasi boilers, your boiler repair company will need to investigate all potential issues with the pump; as its problems with circulation that have caused this error to occur.

The first thing to do, is check the pump is on the right speed setting. A pump that’s set too slow is going cause water to linger in the heat exchanger and overheat, and when it travels around the heating system, it’s going to lose too much temperature.

After assessing the speed setting, the next thing to check is the pump for blockages. They can come in all shapes and forms, including airlocks. You’ll need a heating engineer to bleed the pump using the bleed screw.

Once the pump is bled, they’ll want to flush the system of limescale and heating sludge using central heating cleaner. Even the smallest piece of sludge or limescale in the pump could reduce its ability to circulate water around the heating system.

More importantly, once they’ve done this, they’ll need to protect your system by adding central heating inhibitor (to break down sludge and limescale in future). They’ll then want to install both a magnetic system filter and limescale reducer (to remove sludge and limescale from the system).

Next, they’ll want to check that the pump isn’t leaking. A leaking pump is going to reduce boiler pressure, and that’s going to mean the pump is overworked, to achieve optimum circulation. Typically, a leak can be fixed by replacing the pump seals.

The problem with leaks is that they can cause problems with other electrical components, including the PCB. If water has dripped onto the PCB, it might be that the wiring has been damaged; that’s going to affect the communication between the PCB and pump. It’s going to need to be repaired or replaced.

On most occasions, the pump can be fixed. However, if you need a replacement, including parts and labour, you should expect to pay around £250.

Is the ER15 error an easy one to fix

In order to fix the ER15 fault code, you’ll need to call a Gas Safe engineer. And, that’s because the problem lies with the pump. The pump sits behind the boiler’s casing. Removing this casing is classed as working on a gas appliance, and that’s a job for qualified professionals.

The fault here is extremely like the ER14 fault code; the problem is with circulation. And, like the ER14 fault code, it’s most likely that the problem lies with the pump.

In order to fix the ER15 fault, your boiler engineer is going to need to check things such as the:

  • Pump’s ability to circulate water. Is it airlocked, or blocked with heating sludge or limescale?
  • Current speed setting. Is the speed setting too slow?
  • Connections and wiring. Can the pump communicate correctly with the PCB?

Your engineer will be able to remove airlocks, as well as any heating sludge and limescale. They’ll then check the speed setting to ensure it’s a match to your heating system. And finally, they’ll ensure that the pump is communicating effectively with the PCB. If minor wiring repairs don’t fix the problem, either the pump has failed, or the PCB has failed.

Typically, a pump will cost around £250 to replace. A PCB replacement for a Biasi boiler is going to be closer to £500. With repairs of this size, it might be worth considering whether it’s worth investing this cash in a new boiler with a long warranty.

What does the FL error code mean on my Biasi boiler

The final common error code we see on Biasi boilers, is the FL fault. This is a filling request; there isn’t enough pressure in the system.

System pressure is directly linked to the amount of water the system contains. To increase that pressure, you’ll need to open the valve on the external filling loop (the braided hose, usually below the boiler’s casing).

Most modern boilers work best with 1.3 bar of pressure (be sure to check your owner’s manual for confirmation). So, if your gauge has dropped to 0.5 bar or below, this is going to be the reason the FL error code is being displayed.

But, before you start topping up your boiler with more water, and therefore, more pressure, you need to figure out why the pressure dropped in the first place.

The most common cause of pressure loss in boilers, is leaks. Leaks can come in all shapes and forms, but here’s where you should start looking:

  • Water dripping from the boiler
  • Radiator valves
  • Radiators and towel rails
  • Soldered joints on copper pipe work

If you see water dripping from your boiler, we’d suggest calling an emergency boiler repair company. Electronic components in your boiler could be exposed to water. And, that’s going to mean more expensive repairs.

It’s common for components in boilers to leak. The heat exchanger and the pump are the most common.

Your boiler engineer will find and fix the leak. Once completed, they’ll be able to reset your boiler, which should remove the FL error code from the display panel.

Other boiler issues relating to other manufactures

For more boiler issues then please visit the Boiler Problems And Cures page.