Vaillant Arotherm Owners Thread

[Andre_K (André Kühne)]

@dfeist

That is what I’ve seen anyway. In actual fact my heat-meter is sensitive to dirt and reports -5% after some time, but as soon as it’s cleaned it matches vaillant number almost bang-on. Vailant flow/return temps don’t match heat meter very well though (although vailant sensors may be in outdoor unit rather than internal).

The Vaillant sensors are in the outdoor unit (see my posted screenshot here) and also quite susceptible to outside temperature variations. Quite crappy, but interestingly always wrong in the direction that favors Vaillant’s COP estimates .

@dfeist

So same as earlier firmware. This confims that this is almost certainly by design and not a bug. (other heat-pumps target delta-t of 5k and adjust flow rate to achieve this)

Is there a good reason to target 5 instead of, say, 3? I get that you want a relatively low deltaT but is there a specific reason for 5K?