View Full Version : 407C heat pump / on heating

16-11-2012, 05:05 AM
407C heat pump / on heating
we have a Sirius model heat pump / french product
The heat pump is a 19KW , water to water

Heat pump was underchaged (only 900gr of 407c)
We recharge the heat pump with R407C, the qty is correct (as on the label).


- on low pressure side we have: inlet water 16C, outlet water 12C, pressure of the refrigerant 4.5 bar

- on high pressure side: inlet water 30 C, outlet water 35 C, pressure of the refrigerant is 20 bar

This high pressure is to high for the 35 C water outlet
The top of the compressor is 70C, too hot

If the water outlet is set 40 C we have pressure error (compressor stops)

When we open fully the expansion valve the low pressure rich 5.5 bar and high one 18 bar / the top the compressor is still 70C

Please advice, thx

The Viking
16-11-2012, 10:45 PM
70 degrees discharge temperature sounds low if anything but normal.

Secondly, for us to understand what is going on we will need more information.
Subcooling and superheat are good starting points...



13-03-2013, 06:53 AM

You write that the system was recharged, did you empty the system completely before recharging?
Did you replace the entire charge of refrigerant with new, or did you use som of the old refrigerant in the system again?
If leakage on R-407C systems, will the most volatile refrigerant evaporate first, so you will get the wrong mix...
Did you evacuate the system before recharging?
It may be several reasons of high pressures, it may be air in the system, dirty heat exchanger, low water flow...etc.