Floor heating pipe length too long?

Hello,

The plumber installed the underfloor heating today. The pipe length for all heating circuits in the ground floor, upper floor, and basement is under 100m. However, one heating circuit is about 140m (pipe diameter 16)? The plumber says this is not a problem, the heat pump can handle it. Can I believe him, or could I have problems with pressure drop, insufficient heat output, or something else?

What do you think? Maybe also a plumber among you?

Many thanks, Andreas

Nobody who can answer me the question?

The air heat pump is the Junkers SAS 8-2 ASE split unit with a 25-60 pump. Unfortunately, I have not received a calculation.

What disadvantages arise if the pipe length of the underfloor heating is exceeded?

I assume that either the pump is operating at its respective performance limit or the corresponding heating circuit cannot be supplied with sufficient heat.

I once spent a long time reading about it on the Internet and also heard of lengths of 180 meters. At some point, I accepted that it is a matter of trust. Luckily, I have never heard that the underfloor heating was installed too weakly.