We would like to explain 3 maintenance topics in more detail below!
Solar thermal systems are generally very low-maintenance. However, in order to ensure trouble-free operation in the long term regular maintenance be carried out. If no other intervals are specified, it is recommended that the system to be serviced once a year. If possible, the inspection should take place on a sunny day so that ongoing operation can be observed.
Operating pressure
Over time, the operating pressure in the system may drop. This can be caused by
- Leakage
- Blowing off the safety valve
- Insufficient pre-pressure in the expansion vessel
To check the operating pressure, proceed as follows:
- Compare the operating pressure with the set value or with the original set value from the commissioning log.
- If necessary, adjust the operating pressure back to the setpoint by topping up the heat transfer medium.
Condition of the solar fluid
Every solar fluid ages over time and must be replaced over time. The rule of thumb is : The more optimally the system is operated, the less frequently the fluid needs to be replaced. The following parameters are particularly important for the solar fluid:
- Visual inspection: A sign of progressive ageing is the increasing brown colouration.
- Antifreeze: Measure the antifreeze with a suitable antifreeze tester before the start of each winter.
- Corrosion protection: It is best to check the corrosion protection using pH value measuring strips. If the pH value is < 7, the solar fluid must be changed completely.
Collectors
When visually inspecting the collectors and connections, pay attention to the following:
- Check the collectors for damage.
- Replace damaged tubes according to the operating instructions.
- Check connection joints for possible traces of leakage.
- If possible, remove coarse soiling from the collectors.
