Refrigerant gases

[jakelepeg]

I have a Bodner & Mann 17,000 BTU split aircon unit of the pre-gassed variety. This is the identical machine badged as Honeywell and sold through Screwfix.
I live in France and purchased this unit some years back out here and the pre-gassed refrigerant was the older R407.

The connecting pipework is 4 metres. I have purchased a 2 metre extension (Bodner & Mann) but have found that it is still too short. The instruction book tells me only one extension should be used. Is this because the supplied gas is only sufficient to supply 6 metres of connecting pipe? Would it be possible to connect a second 2 metre extension and then have the whole installation re-gassed?

Through another supplier (Brico) I can purchase a pre-gassed 4 metre extension BUT this carries the R410 refrigerant. I do not know whether the connections would even be compatible but before even considering this is it possible to have a mix of the two refrigerants or is this a definite no no.

Also, as these units come pre-gassed with the pipework already connected to the internal fan unit, can these units actually be re-gassed by an engineer?

All help greatly appreciated

 

[Windup1]

In general , you don't mix refrigerants as they have different characteristics, even if it is classed as a "drop in " replacement. Even if it were a drop in replacement the system would need to be purged and cleaned prior to it being re-gassed. In addition "drop in" replacement refrigerants do not do the same duty.