Daikinl4 code

[charlie patt]

Rzp125dv 1 mfg no 3po856023a l4 code up checked the thermistor all ok dont wont to change the board on invertor dont seem to get on very well with daikin boards any possible other faults to check first? Old unit should come of the wall but need to keep it rolling ta charlie

[install monkey]

few things o check-
Activation of fin thermal switch

Faulty fin thermistor

High outside air temperature

Insufficient cooling of inverter radiation fin

Blocked suction opening

Dirty radiation fin

Faulty outdoor inverter PC board

[The Viking]

Ah,
There is another thing that Daikin don't mention in their manuals...

We have had this happening on a few of the RZPs and what we have found working is to replace the heat transfer paste between the board and the heat sink.
Just take the board off as if you were to replace it, clean the 2 surfaces really well getting rid of all the old paste then apply the new paste and clamp it all back together again.

(Heat transfer paste is about £2 from places like Maplin)



.

[charlie patt]

thanks guys the unit does not run that long before l4 comes up and the heat sink dont even get that hot so i am presumeing its a bad board thanks for input guys

[The Viking]

OK,
May I suggest that you before you order the new board reread my post above as what you are describing is the classical symptom of hardened heat transfer paste...

[charlie patt]

ok worth a go thanks for your input will give it a go

[charlie patt]

fitted a good board to get rid of l4 and even got the paste as suggested was going to make sure it ran ok then fit the old board it runs for about a hr and now brings up l9 code any ideas apart from the comp?

[install monkey]

L9
Outdoor Unit LED
Display
A
5 1 4 2 4 3 4 4 4
Applicable
Models
RZP71~140D
Method of
Malfunction
Detection
Malfunction is detected by converting the current flowing to power transistor into voltage with
CT1 (DC current sensor).
Inverter PC board detects the disorder of position signal.
Malfunction
Decision
Conditions
When compressor overload (except for when startup) is detected
When position signal is disordered
Supposed
Causes

Faulty compressor (lock)

Pressure differential startup

Faulty inverter

The stop valve is left in closed.
looks like the compressor