Danfoss 102es upgrade - programable stat?

[danncus]

Hi my mother in law's heating DHW system is run by a danfoss 102es. she is ill, and i want to replicate what i have at home - a programmable room stat. mine is fitted to a combi which is really straight forward. but this seems to be a little more complicated is there a product available which connects to the existing programmer, or a new programmer with this facility?

thanks in advance

 

[D_Hailsham]

More info about your m-i-l's system please:

Make and exact model of boiler

Is the hot water pumped or gravity heated?

Are there any motorized valves?

Is there a thermostat on the side of the HW cylinder? (Not the immersion heater thermostat)

Finally, what are you trying to achieve?

 

[danncus]

Hi Glowworm ultimate 60FF boiler with HW cylinder below. A twin grundfoss pump is fitted i assume one for CH th other for HW Circ? as far as i recal there is a stat for HW on cylinder also insulated header in loft.

What I want to achieve is we can heat the house a different levels at different times of day eg 7am - 10 am 20 deg 10am- 4 pm 18 deg 4pm-9pm 21 deg 9pm-7am 15 deg what i don't want is for the house at night or in afternoon to cool down too much. TRVs are fitted, but i dont like the idea of leaving the heating on 24/7

thanks

Danny

 

[D_Hailsham]

Hi Glowworm ultimate 60FF boiler with HW cylinder below. A twin grundfoss pump is fitted i assume one for CH th other for HW Circ? as far as i recal there is a stat for HW on cylinder also insulated header in loft.

OK a fully pumped system

What I want to achieve is we can heat the house a different levels at different times of day

The easiest and cheapest solution is to retain the old timer just for the hot water and installed a programmable thermostat for the central heating. This is based on the fact that hot water times are rarely changed.

If your m-i-l's house already has a wall thermostat in a suitable place, then you can replace this with a Honeywell CM907 thermostat. The current wall stat will be fed from the CH ON terminal of the old timer. The connection will have to be moved to a permanent live to prevent the old timer interfering with the new programmer.

 

[danncus]

Thanks - it's beginning to make sense now.

there is no stat fitted at present so i will have to run a new wire. looking at the diagrams (off the net) I assume we are talking about the CM907 switching a live 240v from the CH terminal on the timer, and then would I set the timer to call for CH all the time?

Thanks

Danny

 

[D_Hailsham]

there is no stat fitted at present so i will have to run a new wire. looking at the diagrams (off the net) I assume we are talking about the CM907 switching a live 240v from the CH terminal on the timer, and then would I set the timer to call for CH all the time?

You can do that, but there is then the danger that someone (m-i-l ) will "accidentally" alter the old timer. It would be better to take the supply to the CM907 from a permanent source, e.g the live input to the old timer.

When deciding the location of the CM907, don't forget that the radiator in that room should not have a TRV. If there is one there already you should either set it to Max or remove the head completely. You also have to make sure that the wall stat does not turn the boiler off before the rest of the house has got up to temperature and the TRVs have worked. So you can either put the stat in the warmest room or in the one which take the longest to warm up.

 

[danncus]

absolutely first class advice - clear and concise thank you so much!

i'll let you know how i get on.

thanks again

Danny Cusworth