| Value | Category | Cases | |
|---|---|---|---|
| 1 | Central heating system | 2178 |
20.4%
|
| 2 | Electric heater | 54 |
0.5%
|
| 3 | Boiler | 261 |
2.4%
|
| 4 | Stove | 8203 |
76.7%
|
| Sysmiss | 3388 |