| Value | Category | Cases | |
|---|---|---|---|
| 1 | Central heating system | 3368 |
22.7%
|
| 2 | Electric heater | 112 |
0.8%
|
| 3 | Boiler | 721 |
4.9%
|
| 4 | Stove | 10591 |
71.5%
|
| 6 | Other | 13 |
0.1%
|
| Sysmiss | 695 |