In this article on Saunier Duval boilers: frequent breakdowns, we aim to offer you the best solutions for this brand of boiler. This is one of the most widely used boiler brands in Spain, thanks to its energy efficiency, elegance and sobriety of design, friendly interface and well-organised error code system. That is why it is always useful to have summarised information on the most frequent breakdowns in the Saunier Duval boiler. We will include images and summary tables.
How does the Saunier Duval boiler work?
If we take as a reference the instructions for use of some of the most recent Saunier Duval models, we verify that we are almost always in front of a good boiler. Also the opinions of users and technicians have an excellent average, and Saunier Duval boilers are generally among the best valued and most installed boilers. There is no shortage of boilers of this brand among the “tops” of the best boilers on the market. On average, they are classified as:
- Always elegant boilers, with a minimalist and sober design, which can be incorporated into home decoration, without having to be removed from sight.
- Its body is compact, it does not take up space, so its dimensions and features are perfectly adapted to the needs of the average Spanish family.
- Equipment with high energy efficiency, especially in the most recent models. They classify very well within the new ecological design regulations .
- Very intuitive, friendly and easy-to-use digital interface, through well-designed buttons.
- The error code system (supplied by the manufacturer in the manual) is very well reflected on the boiler control panel display, and is easy to understand.
You can download or read the instruction manuals from the company’s official website through this link: Saunier Duval boiler manuals . In this article we will only see the frequent failures of the Saunier Duval boiler. You can see all the details in the manuals, including full error code tables.
Saunier Duval: the 5 most frequent breakdowns (summary table)
All makes and models of boilers have their weaknesses, and the Saunier Duval is no exception. According to the most experienced technicians, the weak points of the Saunier Duval boilers are these, although they recognise that they are not serious or recurring:
| SAUNIER DUVAL: THE 5 MOST FREQUENT BREAKDOWNS | |
| FAULT | SOLUTION |
| Failure in the DHW membrane due to hardening or breakage. | Replace the membrane with a spare part . |
| Failure in the ventilation or in the expulsion of gases. | Clean or replace the fan or clean the exhaust outlet. |
| Leaks in the manometer capillary. | Always handle the capillary with care, or replace it if necessary. |
| Switchboard failure. | Replace the control unit . |
| False contact in the union between the electronic cards. | Solder the contacts, or replace the electronic card . |
Why doesn’t the boiler turn on? Saunier Duval frequent breakdowns
Among the most frequent failures of the Saunier Duval boiler, there are, of course, starting errors. A boiler fails to ignite for various reasons. Let’s look at a table of startup errors and their solutions, as well as other errors.
| SAUNIER DUVAL: WHY DON’T YOU TURN ON THE BOILER? | ||
| CODE | FAULT | SOLUTION |
| F.22 | Blockage due to lack of water or poor pressure detection. | Fill the water circuit, or replace the water pressure detector. |
| F.23 | F.24 | Excessive rise in temperature too fast due to a blocked or faulty pump, or due to the presence of air. | Unlock or replace the water circulation pump . Purge the system. |
| F.28 | Ignition failure due to: faulty metre, lack of gas flow, clogged condensate pipe, clogged gas outlet, badly connected card, interrupted cable harness, ignition component fault. | Replace the metre , replace the gas regulator , clean the condensate pipe or the gas outlet, connect the card correctly, check the wiring harness, replace the ignition component ( transformer and electrodes ). |
| F.29 | Misfire due to lack of gas. | Check if the gas has run out, or if the regulator has broken down and replace it . |
| F.54 (Combined with F.28 and F.29) | Gas pressure is too low or missing. | The gas cock must be closed: open it. |
What happens if the boiler loses water?
If a boiler loses water, it will also lose pressure, and that can lead to the boiler shutting down until pressure and water loss problems are resolved. There are several reasons why a boiler loses water. Let’s look at the reasons and their solutions:
Normal loss of water by evaporation
There is a percentage of water that will always be lost through evaporation. It is normal within the operation of a hot water circuit, even if it is a closed circuit such as heating. The heating installation is specially designed to minimise the loss of water by evaporation, but it cannot completely eliminate this natural phenomenon, because that is impossible.
The solution for the normal loss of water by evaporation is within the normal management of a boiler: sometimes you have to fill the system with water by opening the filler tap, always paying attention to the pressure gauge, so as not to put an excess of water that causes a rise of pressure beyond what is recommended (between 1 and 1.5 bars, or between 1 and 2 bars, depending on the brand and model: look in the manual).
Water leak in the boiler, the circuit or the radiators
To repair the leak, the first thing is to detect it, which is sometimes not easy. A good clue is the following: if the leak causes the pressure to drop, it is in the heating circuit, which is closed. If the leak does not cause the pressure to drop, then it is in the domestic hot water circuit, which is open.
The safety valve expels water
The safety valve is designed with a specific setting or maximum pressure. When the boiler exceeds the setting of the safety valve, it begins to expel water, until the pressure returns to normal and the safety valve returns to its normal closed position.
That the safety valve expels water is a generic fault. The cause of the loss of water is clear in this case: excess pressure. But you have to detect the cause of the excess pressure, which can be between:
- Excessive water in the heating circuit (the filler valve is faulty or was accidentally left open). It needs to be closed or replaced .
- Presence of air in the heating circuit. The radiators , the circuit and the boiler must be purged .
- The expansion vessel has lost gas or has a broken internal membrane. It needs to be repaired or replaced .
It can also happen that the safety valve is faulty and expels water even though there is no excess pressure. After all, it is a sensitive part. If the safety valve is faulty, it is best to replace it.
The drain valve is faulty
If the drain key is faulty, it will let the water out continuously. The same must be said if the drain valve only gets stuck, but in the open position. In any case, it will be necessary to unclog or replace the drain valve to resolve the loss of water.
What should be done when the boilers fail or stop working?
The answer to the question in the title is: it depends on the type of fault that the boiler has. As can be seen from the error code system in the instruction manual (see the table above), there are 4 types of faults or blockages, and each type implies a different way of proceeding:
- Faults that the boiler itself resolves automatically. For example: transient flame detection errors, which the boiler overcomes by trying to restart itself until it succeeds.
- Faults that the user solves by means of a simple restart or rearm. For example: some of the reasons for error F.28 on Saunier Duval boilers are resolved by manually resetting.
- Faults that the user can solve through some non-complex operation. For example: normalise the pressure of the boiler by opening the filler valve until the pressure gauge indicates the appropriate pressure (it is usually between 1 and 1.5 bars, but it is better to look in your manual).
- Faults that can only be resolved by the intervention of a qualified technician. For example: complex problems of excess or lack of pressure, such as those related to ruptures of the expansion vessel, the heat exchanger or the circulation pump.
So, answering the question: “What should be done when the boilers have faults or stop working?”, it must be said that depending on the error code shown on the boiler display, the user will be able to understand which of the 4 ways correspond to your case: whether to wait patiently for the boiler to restart itself, whether to restart it manually, whether to carry out a simple operation, or whether to seek a technician.