Viessmann Boiler F9 Fault Code
The Viessmann fault code F9 relates to the fan and here we have Q & A or require an engineer for an emergency boiler repair.
The Viessmann Boiler Fault Code F9 Error Common Q & A
Just below, we have a list of common questions relating to the F4 fault code on the Viessmann Boiler.
- What does the F9 fault code mean on my Viessmann boiler?
- If I reset my boiler, will it fix the fan and the F9 fault code on my Viessmann boiler?
- What does the fan do on my boiler?
- Why would the fan still be running after the burner has shut down?
- If there are wiring issues with my fan, can these be fixed?
- How can my boiler engineer test the fan?
- My fan needs replacing, how much is this going to cost?
- What would have caused my fan to fail on my Viessmann boiler?
- How will my boiler engineer be able to check my appliance for water damage?
- What else could have caused the F9 fault code to be displayed?
- If I need to replace my boiler’s PCB, how much is it going to cost?
What does the F9 fault code mean on my Viessmann boiler
If your boiler develops a problem, a fault code is going to be displayed on the control panel. This will help your boiler repair company quickly highlight the potential problems, making the fix quicker and cheaper. In the case of the F9 fault code, the problem lies with the fan.
Your boiler is controlled by the printed circuit board (PCB). The PCB wants to recognise that parts are operating (or not), when it gives them the relevant command. And, it’s able to determine this by monitoring a range of sensors throughout the boiler.
If your boiler is showing the F9 fault code on the display panel, it’s due to the fan running, even when it shouldn’t be. In most scenarios, this is an electrical issue, whereas in others, it could be that the fan is faulty and needs replacing.
If I reset my boiler, will it fix the fan and the F9 fault code on my Viessmann boiler
You shouldn’t be resetting your boiler to fix the fan. The reason manufacturers incorporate a reset function in boilers, is to get your boiler working after the problem has been found and fixed; it’s not a way to fix your boiler.
More importantly, some boiler faults can be dangerous. It’s likely your boiler has locked out as a safety precaution. And, it should stay in its locked out state until it’s been fixed.
As the F9 fault code is going to require the boiler to be dismantled, you should call a Gas Safe heating engineer to come and help you rectify the problem.
What does the fan do on my boiler
From a safety aspect, the fan is one of the most important components in your boiler. It’s the fan that helps to vent harmful gases from your boiler, up and out of the flue.
Your boiler won’t fire into life until it sees that the fan is operating. The PCB wants to know that the draught has already been created to vent gases, before these gases are released from the burner. So, once the PCB sees the fan is running, it will tell the gas valve to open, and the burner to ignite.
If there’s an issue with your fan, your boiler will notice that the air pressure change isn’t correct after it fires up or shuts down. And, as a fan that isn’t operating efficiently could be dangerous, it’s going to lock out your boiler and display a fault code.
Why would the fan still be running after the burner has shut down
Typically, the fan is going to run for a short period, after the burner shuts down. That’s to ensure that all gases in your boiler have been expelled from the property. However, it shouldn’t be running constantly. And, the F9 fault code relates to a fan that’s not shutdown completely, even when it should have.
The most obvious cause of the fault is a wiring issue. If wiring or connections are loose and/or damaged, the communication between the fan and the PCB isn’t going to be efficient. And, that’s going to mean that the PCB either can’t send the correct signals to the fan, or the fan isn’t receiving them correctly.
If this is the case, it’s likely your boiler works sporadically. It will cycle on and off, or not get hot water and heating up to temperature. The fan receives intermittent signals from the PCB and may turn on and off, and the burner will shutdown every time the fan does the same.
If there are wiring issues with my fan, can these be fixed
Your boiler engineer will be able to fix simple issues with wiring and connections. Small sections of wiring can be replaced, whereas connections can be secured where necessary. At this stage, resetting the boiler will usually clear the F9 fault code.
But in some cases, simple fixes like this won’t work. It might be that the fan is beyond repair, and it needs replacing.
How can my boiler engineer test the fan
If the problem here doesn’t relate to wiring or connections, it’s likely the fan is to blame. Your boiler engineer will be able to test the fan using a multi-meter. This will determine if the fan needs replacing, or whether the problem lies elsewhere.
My fan needs replacing, how much is this going to cost
If you need a replacement fan, you should expect to budget around £250; this includes all parts and labour.
What would have caused my fan to fail on my Viessmann boiler
But, before committing to expensive repair bills, it makes sense to determine where the fault originated from. After all, if the root cause of the problem isn’t found, there’s a good chance the problem could reoccur, even after shelling out on expensive repair bills.
Besides old age, water damage is one of the biggest killers of boilers, and especially their electronic components such as the fan.ill my boiler engineer be able to check my appliance for water damage
Water damage is going to come from leaks, and leaks are usually obvious. Typically, they originate from either the heat exchanger, or the pump.
Even a small leak can cause a huge amount of damage. Electrical components in older boilers aren’t well sealed. So, if your fan has been exposed and is damaged, it’s likely that other components are likely to follow.
Your boiler engineer will want to check the heat exchanger for cracks. Cracks develop due to limescale build-up, eventually leading to leaks. If the heat exchanger is the culprit, it’s going to need to be replaced. Typically, the cost of a new heat exchanger is going to be around £450.
But, a more likely culprit, is the boiler’s pump. The seals on heating pumps are partial to degrading, and that’s where the leak is going to occur. Luckily, on some occasions, a service kit can be used to recondition the pump. However, in extreme scenarios, it might be the pump needs to be replaced to fix the leak. And, this is going to cost around £250, including parts and labour.
What else could have caused the F9 fault code to be displayed
Some faults can be a lot more complicated than they seem. Even though the F9 fault code relates to the fan, the PCB needs to be ruled out as a culprit too.
The PCB gives and receives signals to all components, as well as deciding which fault codes are to be displayed. If there’s a fault with the PCB, it stands to reason that the fault code displayed could be incorrect.
If the fan as well as its wiring and connections are in good condition, the PCB will need to be tested. And, your boiler engineer will be able to do this in the same way they did when they tested the fan; with a multi-meter.
If the PCB is showing lack or intermittent power, it’s going to need to be replaced.
If I need to replace my boiler’s PCB, how much is it going to cost
PCB replacements aren’t cheap. Typically, we’d expect a PCB replacement to cost in the region of £400-500, depending on the exact model of boiler that you own.
With this level of cost, it’s worth assessing your boiler’s overall condition. There’s little point spending this much money on an old boiler, if other parts are about to fail.
To ensure parts aren’t about to fail, you should get your boiler repair company to check the heat exchanger, gas valve and pump.
Other Viessmann boiler issues
For more boiler issues regarding the Viessmann Boiler then please visit the Ideal Boiler Problems And Cures page.