FAQ
TL;DR: Tampering with electronic heat-cost allocators can at best reduce recorded usage by 20 %—“The maximum cost savings of 20% can be achieved.” [Elektroda, djlj24, post #54020]—but it risks legal penalties and device damage.
Why it matters: Residents search for fair bills; this FAQ shows what works, what backfires, and the legal lines you mustn’t cross.
Quick Facts
• Dual-sensor allocators compare radiator and room air; if covered they assume 20 °C room temperature [Elektroda, Mathevp, post #56582]
• Devices ignore readings in a summer lock (June–August) to stop phantom charges [Elektroda, Mathevp, post #56582]
• Cooling tricks yield ≤ 20 % lower points, no more [Elektroda, djlj24, post #54020]
• Breaking a calibration seal voids approval and may draw fines [Elektroda, Kuba_eM, post #53216]
• Many models expose an M-Bus port for authorised data download/reset [Elektroda, Kuba_eM, post #53216]
How do electronic heat-cost allocators actually measure my heating use?
Most units carry two sensors: one touches the radiator, the other measures room air. The microcontroller logs the temperature difference over time and multiplies it by a factory factor. Single-sensor models assume a fixed 20 °C room temperature when the air sensor is blocked [Elektroda, Mathevp, post #56582]
Can I reset or reprogram the EEPROM through the M-Bus port?
Only service software with a manufacturer key can issue a reset. Unauthorised writes usually fail because checksums in EEPROM and a seal byte must match; a mismatch bricks the meter [Elektroda, Kuba_eM, post #53216]
What happens if I wrap the allocator in foil or a plastic box?
Covering the unit forces single-sensor mode; the unit then assumes 20 °C room air. If your room is cooler than that, consumption goes up, not down. The best-case saving from lost differential is roughly 20 % [Elektroda, djlj24, post #54020]
Does hanging wet rags on the radiator fool liquid (ampoule) allocators?
Higher local humidity can speed external evaporation and distort the reading, yet results vary with the ampoule fluid’s vapour pressure. Some users saw faster loss, others slower [Elektroda, fachman, #53593; 0__0, #56629].
Can I remove a Caloric 5.5 allocator without the system noticing?
Unlikely. Caloric 5.5 stores removal dates and tamper flags in non-volatile memory. Breaking the mounting pin triggers a tilt or light sensor; inspectors read that at billing [Caloric 5.5 Manual, 2022].
What legal risks do I face if I break the seal?
The seal certifies metrological approval. Housing associations treat a broken seal as intent to defraud and can bill at the highest tariff plus a penalty fee [Elektroda, Kuba_eM, post #53216]
Will adding big aluminum heat sinks to the radiator lower my bill?
Extra fins cool the radiator faster, raising the average temperature difference. The allocator may log more, not less, because the room takes longer to reach set-point [Elektroda, PsychoKombinat, post #17430984]
Does removing the whole radiator shift costs to neighbours?
Yes. The building heat meter still shows total energy. If your apartment records near-zero units, the algorithm reallocates more cost to other flats, effectively making them pay your share [Elektroda, Mathevp, post #56304]
Is reducing the radiator-air temperature difference a practical savings tactic?
Minor. Even perfect insulation caps savings at ≈20 % because the building meter still bills total energy [Elektroda, djlj24, post #54020]
What’s an ethical way to cut heating costs without tampering?
- Install a thermostatic valve and keep rooms at 18–19 °C.
- Reflect heat with certified foil behind radiators (leaving airflow).
- Seal window drafts. These legal steps can cut bills by 10–25 % according to national energy studies [Danfoss, 2019].
How do I legally read my allocator data through M-Bus?
How-To:
- Ask the housing association for written permission.
- Connect an EN1434-3 compliant M-Bus master and set 2400 baud.
- Issue an SND_NKE followed by REQ_UD2; the allocator returns its data block.
This read-only poll sets no tamper flags [Elektroda, Kuba_eM, post #53216]
What edge cases show the risk of overheating the device?
A user’s attempt to external-heat the casing melted the plastic; the allocator still logged spikes, creating suspicion [Elektroda, Mathevp, post #56304] Damaged housings can void any warranty and lead to estimated—often higher—billing.
). In this standard, it is possible to reset the abacus, but: does your meter have such an option, does it have such an interface, etc ...
but see what cunning on their part radiates here. And how not to boot such smarts?
