Issue with Danfoss FP715si Central heating programmer

[sotal]

I've got a Danfoss FP715si programmer.

It's been in for a good few years and has always been inside the airing cupboard.

Occasionally in Winter the programmer would 'crash' - the screen would go blank and both red lights would remain on. We would realise as the radiators would go just warm and the house would feel a little cold. Flicking the isolation switch off and back on again would rectify this.

It seems to have been doing it more often recently so I figured I'd try moving it out of the airing cupboard incase it was the heat affecting it. I drilled a hole in the wall and mounted it in more or less the same place on the other side (so now in the landing).

Now it seems to be worse!

If I switch it on the screen comes on as normal then after a few seconds you hear a click as it starts the heating or water, then the screen goes blank.

If I quickly turn one of them to off before it clicks in then it seems fine, but with both CH and HW on together it seems to crash.

So I'm not sure if the programmer is just duff, or if there is a certain combination of events which is causing the programmer to trip out.


Any ideas!?

 

[sotal]

I see from the similar posts box below that similar faults are common with this programmer.

As it works with just one thing on at once in my case, is it possible to bridge the wires for the Central Heating so that it is in effect on all the time but could be left in the off position?

The reason for this is that we leave the CH in the ON position all the time, then use a wireless room stat to control the CH which has its own timer built in.

 

[CBF]

just get a decent programmer, i've changed two faulty ones already this week

 

[sotal]

Any suggestions as to what is a decent one? Without spending a fortune and only needing very basic functions as it just needs CH left on 24/7 or Off altogether in Winter. And just needs HW to come on and off a few times a day - can be the same every day.

 

[DP]

FP715 is fine. I have had an odd one fail, but the programmer is easy to programme and run. Alternatively, fit a programable room thermostat for CH and let 715 control HW.

 

[sotal]

That's what we have (a programable room stat) so we just leave the heating on 24/7 on the danfoss.

The wireless roomstat then activates the heating during the on time if the temp drops below the set amount and it also has the advantage of having a lower limit set for night time so that if it gets really cold the heating will kick in as well.



But can I bypass the wiring of the danfoss to just make the CH on all the time, so it can then be left switched off on the danfoss? Or does that confuse it?!

It's not been too bad since, only stalled once and a quick reset and it has been fine since.

 

[DP]

Wire at terminal 4 can be transfered to L, which will power the roomstat and make CH channel redundant. Or move wire at 4 (CH ON) to CH OFF terminal which operates the CH system with CH in the off position.

 

[D_Hailsham]

But can I bypass the wiring of the danfoss to just make the CH on all the time, so it can then be left switched off on the danfoss?

That's easy.

Move the lead from Terminal 4 of the Danfoss and put it in Terminal L.

That completely bypasses the CH channel of the Danfoss, so the CH setting is no longer relevant.