cp715si replacement

[iiSCOTT]

Hi, looking for some advise, hoping someone with far more knowledge than me can help.......

Am looking to replace the danfoss cp715si boiler timer and thermostat in my house. Am pritty sure its faulty as CH&HW now doesn't work separately when set to auto, they do work separately own their own manually!
I could just replace it with the same one but where's the fun in that!
Does anyone have any suggestions as to what to replace it with?
Can you just buy any timer and wire it up?
I see all these wirless ones you can control via an app witch would be really good but am just not sure if they will go onto the existing wiring?

Thanks in advance if anyone replies

Scott

 

[DP]

I could be wrong, but I thought only FP715 is able to run independently timed ch and hw cycles.

Plumbcenter offering will use the same back plate

 

[stem]

CH&HW now doesn't work separately when set to auto, they do work separately own their own manually!

Could you translate that into English please.

 

[iiSCOTT]

Central heating & Hot water now no longer work separately when the timer is progamed.( I used to be able to have the hot water on in the morning but leave the central heating off ) now they only work both at the same time, they do still work individually but only if you manually click the +1hr buttons. I've not touched any of the switch settings on the back off the controller or any wiring + i have confirmed they are in the correct positions as per manual. This lead me to believe the controller is faulty?
I was just looking for any suggestions as what to fit in place of the old one? Maybe a wifi controlled one if the wiring allows.

 

[iiSCOTT]

I could be wrong, but I thought only FP715 is able to run independently timed ch and hw cycles.

Plumbcenter offering will use the same back plate

Yes it used to work separately but for some reason it has stopped and now only work manually when you click the +1hr buttons.

 

[stem]

Central heating & Hot water now no longer work separately when the timer is progamed.( I used to be able to have the hot water on in the morning but leave the central heating off ) now they only work both at the same time, they do still work individually but only if you manually click the +1hr buttons.

Ah OK understood, thanks. It's strange though. Sometimes faults that appear to be because of the programmer but are actually caused elsewhere. In this instance, as the CP715si has two internal relays (one for CH and one for HW) and if they are operating individually under certain circumstances and not in auto then it does sound like the the programmer is faulty, provided of course that the CH and HW aren't programmed to be on/off at the same time of course.

I've come across a few faulty Danfoss programmers over time, but this fault is a new one on me.

I could be wrong, but I thought only FP715 is able to run independently timed ch and hw cycles.

I'd got that in my mind and that the CP715si didn't have separate times, but the OP says it used to work separately, and the manufacturers description is somewhat ambiguous.

Am looking to replace the danfoss cp715si boiler timer and thermostat in my house.

If you are planning on a new programmer and thermostat, you might want to consider a smart thermostat that has the functions of the thermostat and programmer in one device.

Hive Dual Channel will fit on the existing CP715si backplate as the wiring is the same. It would just require a small wiring modification to decommission the existing room thermostat.

Other smart thermostats (but not all) also use the standard backplate.

 

[iiSCOTT]

Hive Dual Channel will fit on the existing CP715si backplate as the wiring is the same. It would just require a small wiring modification to decommission the existing room thermostat.

Thank you so much, I wasn't sure if the hive one would fit or work on the wiring.
What is your thoughts on this.... the current position of my timer/programmer is in the airing cupboard and then the thermostat is in the my hallway. Should I be moving the position of the new hive unit to the hallway where the thermostat is?(I relize that will require a sparky to move wires etc but thats fine)
If I fitted the new hive in the airing cupboard then am thinking it won't work correctly due to it not being in the space that I want heated?(am guessing there is a temp sensor in the hive so it would know when to switch the heating on or off)
Thank you
Scott

Ok so I've just realised the hive kit comes with a wireless thermostat so I've just answered my own question!!
Thank you for your advise, I have now ordered and hive unit.!!

 

[stem]

The old wired room thermostat requires 'decommissioning' which involves a small wiring modification. It can't just be disconnected. Basically the existing thermostat live and switched live wires need connecting together somewhere to close the circuit that would be left open by its removal. If you need any help with it post back.

 

[JohnD]

Yes it used to work separately but for some reason it has stopped and now only work manually when you click the +1hr buttons.

I presume on this device "SI" means service interval

Meaning it is designed to deliberately stop the system from working properly.

Is it in a rented home?

 

[DP]

Yes it used to work separately but for some reason it has stopped and now only work manually when you click the +1hr buttons.

I think you are mistaken.

Common time base means hot water and heating run together at selected times ie you can not programme hw to start heating at 4.00 am and heating to kick in at 6.30 am

Independently here means the hot water relay and Ch relay switches independently.
Programming does not allow for independent programming of either channel ie both run to the same timebase.

For clarity, look at FP715 installation instructions. One programmes the six settings for CH and then six for HW, therefore in auto setting both channels will follow the programme set

 

[stem]

I presume on this device "SI" means service interval

It might be service indicator, when selected it advises the user every 12 months that a service is due.

Common time base means hot water and heating run together at selected times

Hmmm.

it used to work separately but for some reason it has stopped and now only work manually when you click the +1hr buttons.

In any event, the OP wants separate control so it's academic really, he's bought a Hive now

 

[DP]

It might be service indicator, when selected it advises the user every 12 months that a service is due.



Hmmm.



In any event, the OP wants separate control so it's academic really, he's bought a Hive now

See that. CP was never running the way Op thought is was