5 solutions for fault F13 in the Saunier Duval boiler


The fault F13 in the Saunier Duval boiler indicates some error on the electronic board of the equipment. And in this case, we say “equipment” and not “boiler”, because error F13 also occurs in Saunier Duval heaters. However, not all models and lines of Saunier Duval boilers have the same causes for displaying an F13 fault. This is corroborated if we review the indications of various brand manuals: there are certain differences between the F13 code in older models and in more recent models of boilers.

In addition, the direct experience of the technicians with fault F13 in the Saunier Duval boiler must be taken into account, since they indicate causes and solutions that do not appear in the manuals. In this article we will include all the details, to provide you with contrasting information points of view that will really help you to solve the F13 fault and to restart the Saunier Duval boiler. Access Saunier Duval spare parts at Suner.

Table of causes and solutions for fault F13 in Saunier Duval boiler

Saunier boilers, in addition to their high energy efficiency and elegant design, are characterised by incorporating a very friendly, intuitive and easy-to-use user interface. This includes a very clear error code system, as well as a very simple reset procedure (which we will look at later).

The Saunier Duval manuals indicate that fault F13 means an error in the main printed circuit of the equipment. Something else that should be noted is that in the manual of some models the error F12 indicates exactly the same: a fault has occurred in the main printed circuit. However, in other models it is clarified that the F12 fault refers rather to an error in the user interface and not in the electronic card itself.

Let’s first see the causes and solutions for fault F13 in the Saunier Duval boiler in the following summary table. After the table we will go into details about the points that require it.

Dirty and poorly maintained boiler or heater.Clean and maintain the boiler or heater. It is mandatory to give at least one annual maintenance to the equipment
Electronic board faulty (this is true for error F13 and for F12)Replace the electronic card. Click here to access Saunier Duval electronic cards .
Fault in the accumulator sensor (NTC probe). This error is especially true in recent models of Saunier Duval boilers.Replace the accumulator sensor.
Fault in the service exchange relay between heating and hot water. This error is especially true in old Saunier Duval boilers.Replace the exchange relay between heating and hot water.
Faulty pressure switch.Replace pressure switch.

Details on fault F13 in Saunier Duval boiler

Not only boiler manuals: also experienced boiler technicians always comment that the error codes displayed by the equipment are only indicative. In other words, they only give indications of which component may be the fault that has blocked the boiler.

This means that the error codes are not absolute and that only a trained person can decide, among so many possibilities, which is the real cause of the problem, and which of the solutions is the ideal one. Hence the importance of going into detail regarding the points that we only present in the table in an introductory way.


A generic solution: Reset the Saunier Duval boiler

When the electronic card has been damaged, this can have many symptoms. For example, one of them is that fault F13 in the Saunier Duval boiler appears only when the equipment is in domestic hot water mode. In these cases, the F13 error can appear when there is a demand for hot water in the house, or even when there is no demand for hot water and the equipment is in standby mode.

The relationship between fault F13 and the DHW is due to the fact that perhaps, as we have already seen in the table, what is faulty is not the electronic card but the storage tank sensor, which does not send the signal to the electronic card correctly. It is something that happens in newer models of Saunier Duval boilers. In these cases, a palliative that solves the situation momentarily may be to reset the boiler. When restarting or resetting the equipment, possibly the F13 fault will have disappeared, at least for now.


The reset is a generic solution for any type of functional failure in a boiler, not only for error F13. Resetting (restarting or rearming) the Saunier Duval boiler can get it out of a momentary blockage it has entered. Almost all Saunier Duval boilers, regardless of their line, model, technology, or age, are reset or restarted in a similar way. Now we will indicate the general steps to do it, taking into account some model variations.

  1. Turn off the boiler. This is done differently depending on the model. On rotary handle models, turn the handle to position 0. On flanged models, slide the flange to position 0.
  2. Wait 5 seconds. Once the control has been placed in the 0 positions, you generally have to wait 5 seconds, regardless of the Saunier Duval boiler line or model.
  3. Turn on the boiler. When the 5 seconds have elapsed, the control (rotary handle or tab) must be placed back in the position I, so that the boiler turns on. This reset will resolve many errors, including the F13 error.

To this, we must add a comment about the design of the control panel. In the less recent models of Saunier Duval boilers, there is no special Reset button, but the restart is done using the same On/Off button. However, the most recent models of Saunier Duval boilers already incorporate a special Reset button, different from the On/Off button. Always read your manual to clear up any doubts, but in these cases, it will almost always be enough to press the Reset button to restart the boiler. The equipment will do the rest.

Problems with the electronic card

When there are fault F13 in the Saunier Duval boiler, if what has failed is the electronic board (which is most likely), it is best to replace the board with a new one. As we are speaking generically for all Saunier Duval boiler models and lines, we cannot give you a specific link to a part. But enter our store following this link, and you will find a wide range of electronic boards for Saunier Duval boilers.


There are cases in which what happens is not that the electronic card is faulty, but only poorly connected, or with false contact caused by humidity, by cables without continuity, etc. Therefore, before replacing the electronic card, or better yet before purchasing it, it is best to check if the current card is properly connected. It will not be the first case in which a simple readjustment of the connections makes the boiler work as if nothing had ever happened.

Detect the damaged part by analyzing the electronic card

There is a check that can be performed by a qualified technician, which helps to detect the faulty part by checking the electronic board method. The check consists of:

  1. Unplug all the connections that reach the electronic card, except the 230 v connection.
  2. Reset the boiler and check if the error F13 no longer appears.
  3. If you don’t get an F13 error, start connecting the components one by one.
  4. When making any of the connections the F13 error appears again, that must be the damaged component.

Accumulator sensor fault

The accumulator sensor is an NTC probe that sends the signal from the accumulator to the electronic card. So in this case it may seem that the fault is in the electronic card, but in reality, it is in the accumulator sensor. To find out if this sensor is faulty, you have to open the boiler, remove it and check it with a multimeter. It is best that this operation is carried out by qualified personnel.


It is also advisable to check the wiring of the sensor, because it may happen that it is not faulty but with false contact or with a poorly made, poorly connected or damaged installation. This may not seem like much, but it could be the problem that hides under the error F13 in the Saunier Duval boiler. If this is the case, the contacts can be cleaned with a pin.

Fault in the heating-DHW exchange relay

Especially in the case of old equipment, error F13 in the Saunier Duval boiler may indicate that the exchange relay between the heating and domestic hot water services has failed. This relay can become expensive, so you have to assess whether it is worth replacing it, or instead take advantage of this and replace the entire boiler with a new one.

To decide whether to change the relay or the entire boiler, it is necessary to take into account not only the cost of the new boiler but also that of a new installation. With regulatory changes in recent years, boiler installations that were done before may not work for new technology equipment. This is the case, for example, of condensing boilers, which will require not only the installation of a forced draft smoke outlet but also a drain.

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