Danfoss Programmer CP15

[dobbin45]

Hi
My daughter has a Danfoss Programmer type CP15 - can anyone confirm that Hot Water and Central heating CAN NOT be programmed independently of each other. Unable to find any instructions on the internet for this model. Was thinking of fitting a Horstmann Centaurplus C27 as a replacement as CP15 uses standard industry backplate.
Any helpful comments would be appreciated

 

[D_Hailsham]

Hi
My daughter has a Danfoss Programmer type CP15 - can anyone confirm that Hot Water and Central heating CAN NOT be programmed independently of each other. Unable to find any instructions on the internet for this model. Was thinking of fitting a Horstmann Centaurplus C27 as a replacement as CP15 uses standard industry backplate.
Any helpful comments would be appreciated

The CP15 is similar to the CP715; the only difference is that the CP715 has 7 day and 5/2 day options. The options are set by the dip-switches on the back.

However, the options you can use depend on what type of heating installation you have.

Does your daughter you have a combi boiler? If No:

1. Is the system fully pumped?
2. Is there a thermostat on the side of the HW cylinder? (Not immersion thermostat)
3. How many motorized valves and what type?

 

[dobbin45]

Hi
The system is fully pumped with a single three way motorised valve. Neither the hot water or central heating have a thermostat [just thermostatic radiator valves].
We have tried to program the CH and HW seperately with no success.
Thanks
Dobbin45

 

[D_Hailsham]

Hi
The system is fully pumped with a single three way motorised valve. Neither the hot water or central heating have a thermostat [just thermostatic radiator valves].
We have tried to program the CH and HW separately with no success.
Thanks
Dobbin45

What is controlling the motorized valve? It needs a room thermostat and a cylinder thermostat as shown below (click on image for larger version):

View media item 69 View media item 70

 

[dobbin45]

Hi
I beg to differ that a room and cylinder themostat are required. Unable to investigate at present, I am sure that on the 12 way connection box both the HW and CH Thermostat connections will be linked out. [ wired as if always calling for heat ] The water temperature is controlled by the thermostat on the boiler. Not the ideal situation but it is the situation that we have inherited.
The question that I asked was can the Danfoss CP15 be programmed for seperate HW and CH Timing? Saying that the C15 and C715 are virtually the same doe's not help as we cannot find the specification of that either.
As the Horstmann Centaur Plus C27 is a recommended replacement I cannot see the problem of fitting this as the Danfoss C15 is working perfectly except that having different HW and CH timing would be a bonus.
Thanks
Dobbin45

 

[gas4you]

CP715 shares the same timebase with the DHW and CH, so cannot be set for seperate times.

For this you need the FP (full programmer)715, which does have a seperate time base for DHW and CH.

 

[dobbin45]

Thanks Dave
You have answered my question fully as expected from a near neighbour. [I am from Brundall - daughter in Seething]
Our best bet seems to be a Horstmann Centaur Plus C27 from Screwfix, Great Yarmouth at £28.99 incl. v.a.t.
All to be done in the hope of cutting the oil cost down next winter.
Regards
Roger

 

[D_Hailsham]

I am sure that on the 12 way connection box both the HW and CH Thermostat connections will be linked out. [ wired as if always calling for heat ] The water temperature is controlled by the thermostat on the boiler. Not the ideal situation but it is the situation that we have inherited.

So the mid position valve will be locked in its mid-position and effectively redundant.
Although you are not required to make any changes, you need to be aware that current regulations require more than just the boiler thermostat to control the boiler. A room thermostat to turn the boiler off when the room reaches the required temperature and a cylinder thermostat to control the HW temperature. It is all explained in the Domestic Heating Compliance Guide.

The question that I asked was can the Danfoss CP15 be programmed for seperate HW and CH Timing? Saying that the C15 and C715 are virtually the same doe's not help as we cannot find the specification of that either.

The CP715 info is on the Danfoss-Randall website

As the Horstmann Centaur Plus C27 is a recommended replacement I cannot see the problem of fitting this as the Danfoss C15 is working perfectly except that having different HW and CH timing would be a bonus

Having independent control over CH and HW temperature would be an even bigger bonus and would save money very quickly.