Ämne: F750 Pressure down

[Farooq Ahmad]

Hi My F750CU pressure gauge goes to zero every second or third day. I wonder, what could be the reason and more importantly what is the usage of this pressure as my house heating still works so wondering what is the reason for that. How it can be fixed?

Thanks for your and information

[Carl N]

The most likely thing is that the expansion vessel is broken (the red one with a pressure gauge).
You can try increase the pressure in it with a bicycle pump (there is a air nipple under the plastic plug on the underside).
But the membrane in it can be broken and then a new vessel is needed, usually it is quite easy to change it yourself.

[HBerggren]

Grey expansion vessel on this model, down to the left, behind the front panel. Put in 0,5-0,63 bar with safety relief valve open, the one marked 2,5 bar.

[Carl N]

Yes sorry, expansion vessel is built into this heat pump.

[Farooq Ahmad]

Thanks for the tips. let me check that and I will get back to you if it fixes the problem.

[DonPablo]

Open the securityvalve, and pump in som air in the vessel. Ill bet you dont have any airpressure left in it.