Saunier Duval calls on the Climalife engineering and services team

Design of charging stations and implementation of preventive maintenance for its production facilities.


Saunier Duval case study

 A fast growing market


To meet market demand driven by the energy transition and the possible ban on gas boilers from 2030, Saunier Duval needs to expand its production capacity for heat pumps and ensure the long-term future of its equipment. The Nantes plant produces water heaters and heat pumps. 60,000 units were manufactured in 2022 and 118,000 are planned for this year. The challenge is to continually adapt its production facilities to produce more, while complying with the strict criteria defined by the Vaillant group.​

Before going into production, a new heat pump model is first validated by a series of tests in a climatic chamber where extreme operating conditions are reproduced. To ensure the durability of the product, the units undergo a helium leak test as well as a series of in-depth operating tests (electrical safety, conductivity, solenoid valve triggering, changeover between hot and cold modes, speed, etc.).​


Saunier Duval, which has been awarded the "factory of the future" label, has a policy aimed at reducing its emissions by implementing measures such as waste sorting and carbon offsetting, as well as choosing the most suitable refrigerant for heat pumps. A range of R-290 heat pumps was launched in 2019. 



The creation of customised workstations


To adapt the production tool, our engineering department* has designed new ATEX machines, capable of handling the two fluids currently used (R-410A and R-290) but also scalable to low or medium pressure flammable fluids. A real asset in terms of flexibility for Saunier Duval, which is waiting for the publication of the future F-Gas before deciding on the next fluid to be used.

The charging stations, which can be used to draw a vacuum of up to 5 mbar before charging the heat pump, have been designed to be adaptable, and adjustments will be made at HMI level.


« The added value of the Dehon Group's engineering is that it is able to make bespoke solutions thanks to its technical expertise. The machines are part of our company's component and process traceability measures », explains Patrick Lucas, Project Engineer. 






Preventive maintenance


The aim is to limit production downtime by implementing annual preventive maintenance. Level 1 maintenance is carried out by Saunier Duval's maintenance department. However, machines are becoming increasingly complex and specific, and it is not possible to master all the skills and have all the required certifications in-house. To this end, the company organises a one-week production shutdown every year to involve all the trades in level 2 maintenance.  Saunier Duval calls on Climalife to maintain its charging stations.

*Engineering (study and design) is carried out by Crealis, a 100% subsidiary of the Dehon Group.



A maintenance programme tailored to each piece of equipment​


Depending on the system to be checked, maintenance operations are defined and planned by qualified Climalife technicians (F-Gas certification, PED, electrical accreditation, etc.). Our work covers all the points listed below, as well as checking that the installation complies with ATEX regulations and guaranteeing the initial performance of the charging stations.​
Maintenance is carried out in compliance with the regulations in force: PED, ATEX, electricity and machinery directives. ​
For Saunier Duval, the stages are divided according to whether the process or control part is involved and were carried out on each of the load stations as well as on the external storage.​



For controls : For the system :
General inspection SKID inventory​
Regulatory electrical inspection Draining the installation
Safety tests​ Cleaning/replacement of filters​
Leak detection tests Pump maintenance​
Automated HMI Nitrogen pressure test​
Instrumentation / Scales* Evacuate
Pneumatics Re-gassing
Thermography*​ Leak tests
Calibration of analogue sensors**​ Cleaning


*(does not replace that which must be carried out by an authorised body)​
**co-ordination of the calibration of analogue sensors by a COFRAC-accredited subcontractor.​ 





At the end of the operations, a full maintenance report on the installation is given to the customer, together with a leak test report for each installation and a calibration report for the analogue sensors (supplied by a subcontractor). This is also an opportunity to discuss any problems encountered during the year with the customer, to analyse and deal with them and to propose improvements. ​ 



About Saunier Duval

In 1907, Charles Saunier, a polytechnician, and Maurice Duval, an industrialist, joined forces to take over a public lighting business, before launching into the production of hot water heaters in the 1920s. ​
In the 1950s, Saunier Duval expanded strongly into the commercial sector, opening branches throughout France. The company launched the first combination boilers, then acquired the Nantes industrial site in 1965. ​
In 1990, Saunier Duval was bought by the British group Hepworth and expanded internationally.​
In 2001, the Vaillant Group acquired Hepworth. ​Group turnover 2022 = € 3.4 billion​
Number of Vaillant Group employees = 16000​.  Number of Saunier Duval Nantes  employees = 1300​.