Saunier Duval Repair Service in Millfield

What does error code 13 mean on a Saunier Duval Themaclassic boiler?

Error 13 on a Saunier Duval Themaclassic boiler indicates a main board fault. The main printed circuit board is faulty. Contact a qualified heating engineer immediately as the board will likely need replacement.

What does error code 05 mean on a Saunier Duval Isofast boiler?

Error 05 on a Saunier Duval Isofast boiler indicates overheating. Switch off the boiler and allow it to cool down completely for at least 30 minutes before resetting. If the fault recurs, contact a qualified heating engineer.

What does error F19 mean on a Saunier Duval Condens boiler?

Error F19 on a Saunier Duval Condens boiler indicates the central heating thermistor is unplugged. The sensor is not connected properly. Switch off the boiler and contact a Gas Safe registered engineer to secure the connection.

What does error F24 mean on a Saunier Duval Condens boiler?

Error F24 on a Saunier Duval Condens boiler indicates the return heating temperature has exceeded 90°C. This may indicate poor pump operation, lack of water circulation, or closed heating valves. Switch off the boiler and allow it to cool for at least 30 minutes. Contact a Gas Safe registered engineer to diagnose the circulation issue.

What does error code 09 mean on a Saunier Duval Isofast boiler?

Error 09 on a Saunier Duval Isofast boiler indicates a water pressure sensor fault. Check the pressure gauge on your boiler. If pressure appears normal but the fault persists, contact a Gas Safe registered engineer.

How does condensation mode work on a Saunier Duval boiler?

Condensing boilers recover heat from flue gases by condensing water vapour, which significantly improves efficiency. For optimal condensation, the return water temperature should be below 50°C. This allows the boiler to extract maximum heat from the combustion gases. Properly configured condensing operation can reduce gas consumption by up to 30% compared to older non-condensing boilers.

Should I leave my Saunier Duval boiler on all the time?

Modern condensing boilers like those from Saunier Duval are designed to be efficient when running on demand. Using a room thermostat and programmer to control when heating is on is generally more efficient than leaving the boiler running continuously. However, the boiler should remain powered on (even in summer) so that frost protection can activate if needed.

What does the condensate pipe do and can it freeze?

The condensate pipe carries acidic water produced during the condensing process safely away from the boiler to a drain. In cold weather, this pipe can freeze if it runs externally, causing the boiler to shut down with a fault code. To help prevent freezing, ensure external condensate pipes are adequately insulated. If the pipe does freeze, you may carefully pour warm (not boiling) water over the frozen section to thaw it, then reset the boiler. If freezing recurs frequently, ask a heating engineer about rerouting the pipe internally.

How do I use the temperature controls on a Saunier Duval boiler?

Most Saunier Duval boilers have two temperature selectors: one for domestic hot water and one for central heating. For domestic hot water, the range is typically 38°C to 60°C, with an ECO setting suitable for everyday use. For central heating, the range is typically 38°C to 73°C.

What is the pre-heating or WARM START function on a Saunier Duval boiler?

The WARM START or pre-heating function reduces waiting time when you turn on a hot water tap. In ON mode, the boiler maintains the heat exchanger at the required temperature between 5am and 11pm for instant hot water. In AUTO mode, the boiler learns your household patterns and pre-heats just before your typical first use of the day. In OFF mode, this function is disabled and you may experience a short delay before hot water arrives.