An optimally configured heating system saves money and reduces CO2 emissions. Homeowners should therefore have specialists inspect their heating system after it has been operating for a certain length of time.
What many people do not know is that a heating-system check is actually mandatory for residential buildings with six or more homes. This is stipulated by Section 60b of the German Building Energy Act (GEG). The provision applies to heating systems that use water as the heat-transfer medium, including gas, oil and wood heating systems. They must be inspected after 16 years of operation. Heating systems installed in 2010 therefore become subject to mandatory inspection this year. This is highlighted by Zukunft Altbau, an information programme funded by the Baden-Württemberg Ministry of the Environment.
Heating systems installed before the cut-off date of 1 October 2009 have until the end of September 2027. Systems with standardised building automation and those subject to a contractual agreement to improve energy efficiency are exempt from this rule. A separate inspection obligation applies to heat pumps in buildings of this size. The Zukunft Altbau team answers questions on the subject free of charge by telephone or email.
Which deadlines apply?
According to the GEG, owners of residential buildings with at least six homes must have specialists inspect the building’s heating system after several years. The deadlines for the mandatory inspection are staggered according to the age of the heating system, as the following examples show:
Heating systems installed after 30 September 2009 must be inspected after 16 years.
- Installed in October 2009: inspection had to be completed by September 2025.
- Installed in April 2010: inspection by March 2026
- Installed in September 2010: inspection by August 2026
- Systems installed by 30 September 2009 have somewhat longer overall for the inspection, namely until 30 September 2027.
If specialists determine during the inspection that the system needs to be optimised, homeowners are required to have these measures carried out within one year. The purpose of the law is to use energy as efficiently as possible. The system’s energy losses must first be identified and then remedied.
Checks from controls to pipe insulation
During the heating-system inspection, heating installers, energy advisers or chimney sweeps first determine whether the system’s control settings are appropriate for how the building is used. They also check whether hydraulic balancing has been carried out. They test whether the flow temperature can be lowered and whether an efficient heating pump is fitted. Finally, they check whether the pipes are insulated throughout.
If the heating system’s controls are set correctly, the individual rooms in the building are heated consistently with the appropriate flow temperature. Specialists recommend lowering the flow temperature at night by setting the timer programme. Reducing the temperature one or two hours before bedtime and raising it again shortly before getting up saves heating costs. This approach is particularly worthwhile in older, poorly insulated houses.
Summer operation? Switch off the heating
Homeowners should switch the heating off entirely during the summer half of the year. It is sufficient to leave the hot-water supply running. When it becomes cooler, the system can be switched back on once the outdoor temperature falls below the heating threshold. This prevents the heating from starting unnecessarily during cooler spells in summer or early autumn.
Optimising performance through hydraulic balancing
Hydraulic balancing ensures that every radiator in the house receives precisely the amount of heating water it needs. This is especially important for radiators installed far from the boiler. Hydraulic balancing works as follows: a heat-load calculation determines how well the building is insulated. Specialists calculate how much heat each room requires and therefore the water-flow requirement of each radiator. This can be preset at the valve bodies of the individual radiators. The technicians also calculate how much pressure the heating pump must provide for heat to be distributed evenly throughout the house.
Once the system has been hydraulically balanced, the heating pump automatically reduces the volume of water it circulates. The flow temperature can often be lowered at the same time, saving energy and money.
Important: The somewhat more involved calculation method B should always be used for hydraulic balancing, rather than estimation method A. Calculation method B is mandatory for owners of larger buildings with six or more homes. Specialists are required to document the calculations in writing and hand them over to the homeowners.
Examining the heating pump and pipes
The heating pump ensures that hot water travels from the boiler to the radiators. If the device is outdated or uncontrolled, it can easily consume excessive electricity. During a heating-system check, specialists therefore also determine whether the old heating pump may need to be replaced. Modern high-efficiency pumps use around 90 per cent less electricity than conventional pumps, saving between 50 and 150 euros in electricity costs each year.
Good insulation around fittings and pipes also helps save energy. Poorly insulated pipes lose a great deal of heating energy. Specialists recommend that the insulation around a pipe should be at least as thick as the pipe’s own diameter.
Arrange an appointment early
Homeowners can combine inspection of their heating system with an existing appointment, such as heating-system maintenance, a fireplace inspection or a chimney-sweeping visit. The inspection may also be certified during hydraulic balancing. In view of the deadlines, it is certainly advisable to arrange a heating-system check well in advance.