Vaillant Group • Founded 1963 • France
Repair and spare parts for Saunier Duval boilers in Madrid
Specialised technical service for the entire Saunier Duval range in Madrid. Repair of ThemaFast, ThemaClassic, Thalia Plus, and Isotwin boilers, with quick diagnostics and original spare parts.
💡 Direct response
Saunier Duval is a French brand of boilers founded in 1963 and acquired by the Vaillant Group in 2003. It shares the technical platform and PCB with the equivalent Vaillant models, which makes it easier to locate spare parts. Its boilers ThemaFast and ThemaClassic They are among the most installed in Madrid and the metropolitan area between 2005 and 2018.
🏆 Vaillant Group
Availability and lead time are confirmed for the specific reference and destination before accepting the order. Not all parts are in stock or have the same supply time.
High efficiency
Thalia Plus and ThemaFast condensing models, class A. Compatible with Exacontrol and OpenTherm control.
📦 Spare parts in stock
Check availability and shipping conditions for the specific reference. The timeframe depends on stock and destination; it is confirmed when preparing the proposal or order.
Saunier Duval product range
Condensing boilers
- ThemaFast F - Condensing combi boiler, sealed forced draught. The most installed range in Madrid.
- Thalia Plus – high-efficiency condensing, compatible with renewable energies and hybrid heat pump.
- Isotwin F – Condensing boiler with integrated stratified DHW tank (30 L). For buildings with high demand.
Standard and conventional boilers
- ThemaClassic C - Boiler for heating only, sealed forced draught. Widely used in Madrid 1998-2010.
- Themaplus C – advanced version of the ThemaClassic, with digital display and more regulation functions.
- Opalia - Wall-mounted atmospheric boiler, requires conventional chimney. Common in flats with classic installation.
Most common fault codes
Saunier Duval shares the codes of the Vaillant platform in condensing models. The most common ones:
| Code | Meaning | Common cause |
|---|---|---|
| F.01 | Flame sensor | Dirty ionization electrode or control board |
| F.07 | Spontaneous flame | Defective gas valve or short circuit in sensor |
| F.11 | DHW NTC sensor | Domestic hot water (DHW) sensor fault |
| F.22 | Low pressure | Water below 0.5 bar: refill or repair leak |
| F.28 | Ignition fault | Gas cut off, electrode or gas valve |
| F.29 | No re-ignition | Ionization electrode or control board |
| F.75 | No pressure detected | Circulator pump or faulty pressure sensor |
Saunier Duval parts: availability by reference
Check availability and shipping conditions for the specific reference. The timeframe depends on stock and destination; it is confirmed when preparing the proposal or order.
- PCBs (ThemaFast, ThemaClassic, Thalia Plus)
- Circulator pumps and hydraulic groups
- NTC sensors for heating, DHW, and flue gases
- Gas valves and solenoid valves
- Extractors, fans, and electrodes
- Heat exchangers and gaskets
Frequently Asked Questions about Saunier Duval Boilers
The most frequently asked questions we receive about Saunier Duval boilers:
Are they the same? Vaillant Group (acquisition 2003), but they are distinct brands. They share the same technical platform and many internal components (PCBs, valves, sensors), but have different external designs and some specific components. This facilitates the location of spare parts, but not all are directly interchangeable.
The ThemaFast F It is a combi boiler (heating + instant DHW), with a plate heat exchanger for hot water. The ThemaClassic C It is heating only, without integrated DHW production (the dwelling has another unit for hot water). Both are sealed forced draught, very common in Madrid between 2000 and 2015.
F.28 indicates ignition faultThe boiler attempted to ignite unsuccessfully and locked out for safety. Check that the gas valve is open and the gas pressure is correct. If the gas is fine, it could be a dirty ignition electrode, a faulty gas valve, or the control board. Reset using the reset button and if it recurs, call the technician.
Before replacing a boiler, compare the full cost of repair and new installation, equipment condition, material availability and your home's consumption. A percentage of savings or amortisation period cannot be promised without studying the case.
The most common causes are: blocked plate heat exchanger due to limescale (common in Madrid's water), Defective DHW NTC sensor (F.11) stuck 3-way valve or faulty flow meter (does not detect DHW flow). If the boiler heats for heating but not for the tap, the heat exchanger or the 3-way valve are the main suspects.
Boiler maintenance is adjusted to the model and contracted plan. Check maintenance for current prices, visits, and assistance limits; it does not imply an official certificate or guaranteed arrival time.
Does your Saunier Duval boiler need servicing?
Indicate the model and the fault code. We will guide you before the visit.