Zanussi Boiler Error and Fault Codes

zanussi boiler error and fault codes

When the boiler breaks down, it can be tempting to start calling around for an engineer or consider buying a new boiler.

With most types of boilers, some problems and error codes can be resolved by the homeowner, meaning that you can have your hot water and heating running in no time at all.

zanussi boiler error and fault codes

The challenge to knowing what the problem is, comes from understanding the Zanussi boiler error codes.

These two-digit codes provide an insight into what the problem might be, and they’ll be displayed on the control panel of your boiler. Even the best combi boiler can give in at some point.

While everyone wants to avoid an expensive call-out fee, some problems will need a qualified gas engineer to visit your home and establish the issue. Of course, if you have a boiler cover policy in place, then life is really easy! One phone call, and the engineer will be there with no unexpected bill to pay. Some boiler cover policies also pay for a replacement boiler!

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Common Zanussi Boiler Error Codes

As with all manufacturers, there are a few Zanussi error codes that are more common than others.

So, in this section, we’re going to focus on two, the F1 and C0. If you’re getting different Zanussi fault codes, then do check further down in this article for a complete list of all the codes which your boiler might display.

Zanussi boiler error code F1

The F1 error code means that the boiler system has a water pressure that is too low. This then means that the system cannot function correctly, resulting in a lack of hot water.

If the pressure gauge on your boiler shows at less than 1.0 Bar, then it’s likely that it’s too low.

Low pressure is generally caused by one of two reasons:

1.      A Leak in the Zanussi Boiler System.

The smallest of leaks can, over time, cause the pressure in your heating system to drop. So before topping up your system, take a look around your home for any signs of a problem.

This is likely to show up as small damp spots under the radiators and pipes. If you can’t spot anything and the pressure keeps dropping, then you’ll need to call out an engineer to check inside the boiler system.

Zanussi boiler error codes and fault codes

For more information on managing boiler leaks, have a look at our guide focussing on just this issue, which you can find here.

2. Bleeding Radiators

If you’ve recently bled the radiators, then that may have caused the loss of pressure. That’s simply because when the radiator is bled, it causes the release of air, resulting in the lowering of pressure in the boiler system.

The good news is that increasing the pressure is something which the homeowner will be able to fix all by themselves, and need not get a brand new boiler installed.

To repressurise the system simply means adding more water via a filling loop. Your boiler may have a filling loop permanently connected, or you may need to attach it. Then:

  1. Switch your boiler off and allow it time to cool down
  2. Check that the filling loop is securely attached
  3. Open each of the valves, and you should hear the cold mains water entering the system
  4. Watch the pressure gauge and wait for it to reach 1.5 bar
  5. Then you can close each of the valves.
  6. Now you can switch on the boiler
  7. If you have a removable filling loop, then undo each end, being careful not to spill any water still in the loop.

If you need further advice on repressurising your boiler, have a look at our guide to high and low-pressure issues. Don’t forget to also we check your manual, and you could also get in touch with Zanussi themselves.

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Zanussi boiler error code C0

zanussi boiler error codes & faults

The error code C0 means that there is a problem with the boiler chip card (BCC). The BCC is responsible for synchronising the printed circuit board (PCB) and the boiler. If there is a problem with the BCC, then the PCB won’t work, and neither will the boiler. Unfortunately, this may be where you start thinking about how much a new boiler cost.

This error code will need an engineer to visit to establish what’s causing the issue with the BCC.

All Zanussi Error Codes

Error CodeZanussi Boiler Problem
C0A fault with the activation of the Boiler chip card (BCC)
C2A fault with the boiler chip card (BCC)
F1Water pressure too low
F2Loss of flame to heat the water supply
F3A fault with the fan
F4An issue with the flow thermistor
F5An issue with the return thermistor
F6Failure of the outside sensor
F7Problem due to the mains voltage being too low
F9The printed circuit board (PCB) is unconfigured
L1There is no water flow, or there is an overheat in the flow temperature
L2Loss of the flame
L5During 15 minutes, there have been five boiler resets
L6A lockout has happened due to a false flame warning


When your Zanussi boiler isn’t working as it should, it’s essential to get it working as quickly as possible. No-one wants to have to deal with a lack of hot water or heating for long.

There may, though, come a time when more repairs are just not viable, or the cost of fixing the boiler is too expensive.

That’s when the fixed price quote from Boiler Central can make having your new boiler installation be an incredibly easy and stress-free process.

We have some great boiler deals on the best system boilers, combi boilers & heat only boilers in just a few clicks.

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