FER Hawk DHW Problem

[fra]

Hello

Can anybody please help with the following problem I have with my FER Hawk combi boiler?

The boiler will not fire up for DHW when the CH is not on and the boiler is stone cold.

It works fine when the CH is on, and for a while thereafter.

Both CH and DHW thermocouples (thermistors) have been changed, but the problem remains.

Any help would be gratefully appreciated.

Thanks.

 

[Agile]

I would want to ask the person who changed these two thermocouples (?).

Sounds like a flow sensing device has failed.

Tony

 

[fra]

Thanks, Tony.

Would this be the Flowmeter referred to in the manual?

Other than that, I can't see a specific flow sensing device.

Regards,


Pete

 

[fra]

Hello again,

The flow switch has been checked for continuity and it's working fine (i.e. LED2 comes on and zero Ohms is measured across the flow switch when the hot tap is turned on).

As the thermistors have been replaced, do you think the fault is likely to be the control board, and/or is there anything else you can suggest?

Many Thanks.


Pete

 

[ChrisR]

Domestic Hot water tap open (Flow rate greater than 2,5 l/min)
[code:1]
LED OK FAULT POSSIBLE CAUSE OF FAULT
1 1 0 No mains electricity/switches off/fuse blown.
2 1 0 D.H.W. flowmeter (136) not operating.
3 X X Not required for D.H.W.
4 1 0 - D.H.W. sensor (42) not connected or D.H.W. temperature too high
5 0 1 - Waiting time operating: replace P.C.B.
6 1 0 Short circuit on D.H.W. sensor (42) or resistance lower than 500 Ohm- C.H. limit thermostat (50) open circuit (pump run)
- C.H. water pressure low (114 open circuit)[/code:1]

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