Vaillant Boiler F89 Fault Code
The Vaillant fault code F89 - Electrical Error To Pump problems Q & A, and if you require an engineer for an emergency boiler repair, feel free to use our service.
The Vaillant Boiler Fault Code F89 Error Common Q&A
Vaillant Boiler F89 Fault Code
- Why is my Vaillant boiler showing the F89 fault code?
- What are the most common faults that cause the F89 fault code to be displayed?
- If an F89 fault code is displayed, is my boiler dangerous?
- If the boiler isn’t dangerous, will resetting it clear the F89 fault code and fix the boiler?
- What does the heating pump in my boiler do?
- What are typical signs that there’s an issue with the pump?
- What causes errors in the pump’s circuit?
- Why do connections become loose if they are protected by the boiler’s casing?
- How will a boiler engineer be able to diagnose a problem with loose or damaged connections?
- Can frayed or damaged wiring be repaired to fix the F89 fault on my Vaillant boiler?
- What causes a short circuit, and how can it be fixed to clear the F89 fault code?
- What causes water damage to electrical components?
- Is there a way to tell if my boiler has water damage?
- What needs to be done to fix the F89 fault code and the water leak at the same time?
- Is there anything else that could be causing the issues I’m experiencing with my Vaillant boiler?
Why is my Vaillant boiler showing the F89 fault code?
According to Vaillant, the F89 fault code will displayed on boilers that have an electrical error with the heating pump.
What are the most common faults that cause the F89 fault code to be displayed?
Electrical faults that relate directly to the pump are usually limited to:
- An error on the pump’s circuit
- Connections between the pump and the PCB (printed circuit board) are loose or damaged
- A short circuit on the pump
If an F89 fault code is displayed, is my boiler dangerous?
Boiler’s that lockout and show a fault code are rarely dangerous. But, that’s only because the lockout procedure has been put into place. All boiler’s have specific lockout procedures, depending on the fault code that is displayed.
In this case, the lockout could help prevent further damage to electrical components, especially if water damage has occurred.
If the boiler isn’t dangerous, will resetting it clear the F89 fault code and fix the boiler?
The boiler is only danger-free because it’s locked out. You should contact a Gas Safe engineer.
They will fix the fault that’s causing the F89 error code. After testing to confirm the fault is cleared, they will reset your Vaillant boiler for you.
What does the heating pump in my boiler do?
The heating pump in your boiler circulates hot water.
Once the heat exchanger has heated water, the pump circulates it around pipework, towel rails and radiators.
Water travels throughout the central heating system and comes back to the boiler via the return pipe. This water will have lost heat (that’s been absorbed by pipework, radiators and towel rails) and will be re-heated.
If there’s a fault with the pump, it won’t circulate the water.
The boiler’s PCB recognises that the water is up to temperature, but isn’t circulating out of the boiler (via the flow) or returning to the boiler (via the flow). And, that’s why it locks out.
What are typical signs that there’s an issue with the pump?
If a pump isn’t fully functional, you’ll notice that both hot water and heating isn’t getting to temperature.
That means that water from taps isn’t heating up, and radiators won’t respond to heat demand from the thermostat.
Every time you switch on your boiler and reset it to clear the F89 fault code, it will lockout. Simply because, the reset doesn’t fix the problem.
What causes errors in the pump’s circuit?
Diagnosing electrical problems isn’t easy.
Pump issues usually stem from:
- Damaged or loose connections
- Frayed wiring
- A short circuit
- Water damage
Why do connections become loose if they are protected by the boiler’s casing?
It’s rare for newer boilers to suffer from loose connections. However, it’s a common fault on older Vaillant boilers.
Boiler’s make noise, and that noise is created by vibrations. Components such as the pump and fan both vibrate, and over years this can work connections loose.
If your boiler is excessively noisy, there’s a good chance there’s a fault with the component making the noise. For instance, the fan might be partially seized. If it is, there’s a good chance it’s putting excess wear on the motor.
If you think your boiler is noisier than it should be (or it’s recently become a lot noisier), it’s worth asking your boiler engineer to inspect the main components in the boiler (such as the pump and fan).
A quick-fix on these components could not just stop the noise, but help to prolong their life. And, both parts can cost more than £300 to replace.
So, the quick-fix could save you money too.
How will a boiler engineer be able to diagnose a problem with loose or damaged connections?
Most electrical faults can be diagnosed by testing electronic components with a multi meter. This tool allows an engineer to see which parts of a circuit are getting power, and if there’s a break in the circuit.
Before doing this, the easiest way to find loose or damaged connections is a visual inspection. Loose and damaged connections are usually incredibly easy to spot.
If the connections are intact but loose, they simply need to be re-secured.
However, if there’s damage to the connections, they need to be repaired or replaced.
Can frayed or damaged wiring be repaired to fix the F89 fault on my Vaillant boiler?
worth repairing components unless they are incredibly expensive.
If frayed wiring is an issue, replacing that section of wiring is the most cost-effective option; long term.
What causes a short circuit, and how can it be fixed to clear the F89 fault code?
A short circuit is a common way to describe any fault with an electrical circuit. Electricity is channelled down the incorrect path, or stops suddenly (for instance, due to a loose or damaged connection).
To determine where the fault lies, all wiring will need to be tested to find and fix the fault using a multi meter.
What causes water damage to electrical components?
As parts in a boiler wear out, they become less efficient. More importantly, boiler parts whereby water passes through can leak.
The heat exchanger (which heats water) and the pump (which circulates this heated water) are two of the most common examples.
There are two ways that water damage occurs:
- Leaking water drips directly onto connections, causing a short circuit or damage
- The internal heat of the boiler’s components creates condensation, and this settles on electronic components
Is there a way to tell if my boiler has water damage?
Not all water leaks will be visible. A small leak will result in water being contained in the boiler.
However, larger leaks will mean that water drips from the casing. If you have drips or pools of water below your boiler, that’s a good indication that parts inside the boiler are leaking.
But, there are two other obvious signs of water damage:
- A slight burning smell – this is an indication of water dripping directly onto electrical components
- A loss in boiler pressure – any loss of water from your heating system (i.e. boiler parts leaking) will result in a loss of pressure
What needs to be done to fix the F89 fault code and the water leak at the same time?
There’s little point fixing an electrical component, if a leak is still present. The leak needs to be found and fixed.
In the case of a leaking pump, sometimes the seals can be replaced to solve the problem; that’s a cheap fix.
However, when the issue stems from a cracked heat exchanger, you’ll need to consider a new boiler.
If your boiler is out of warranty, over 10 years old (and therefore, highly inefficient), it’s unlikely replacing the heat exchanger is cost effective.
A heat exchanger replacement can cost more than £300. But, if the heat exchanger is showing signs of wear, there’s a good chance other parts will need to be replaced soon too.
Is there anything else that could be causing the issues I’m experiencing with my Vaillant boiler?
The fault codes on boilers are not an exact science. They aim to indicate the problem, but they don’t highlight the exact fault.
Some Vaillant boiler’s will display multiple fault codes. And, that can help to narrow down the problem.
As an example, the F89 could be a problem with the wiring harness between the pump and the main PCB. The PCB controls all electronic components within the boiler.
If your boiler was to also show a F84 fault code, there could be a bigger issue at hand. Because, the F84 fault code highlights an error between the wiring harness from the NTC thermistors and the PCB.
Both fault codes have a potential fault that relates to the wiring to the PCB, and that could mean the PCB is at fault rather than the pump/NTC thermistors.
For this reason, it’s important to check all electronic components (as well as their wiring) using a multi meter, before making any expensive repairs.
Other Vaillant Fault Codes And Error
If your looking for the list of error codes relating to the Vaillant boiler then please read the article Vaillant Boiler Fault Codes And Cures