Replacing a UP2 controller unit

30 Sep 2009
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United Kingdom

I have just moved home and the new house has a Worcester 30 CDi boiler with a UP2 dual controller. I know it is an upgrade, from my last house, but it feels like a bit of a downgrade. In the old house we had a Worcester 28 CDi and a Honeywell CM927 wireless room stat/programmer.

I believe the cylinder has a wired thermostat connected to the boiler and that part all seems to be good in that if is programmed for 30mins each morning, but it only ends up firing for 15mins on average for all the hot water we need in a day. It's just taken some getting used to after having a system that just provides hot water on demand.

My biggest issue is that there is no room stat at all. I spoke to someone who suggested I just buy another CM927 and connect it up to the UP2 (disabling the heating timer). However, I have also seen the Honeywell RF2 Pack2. This seems to be a nice direct replacement for the UP2 and cleaner solution. However, I am unclear as to how advanced the heating program-ability of the RF2 is compared to the CM927. For example, in the last house I was able to to set the temperature based on time and day of the week. Some days I had it set to 16-18 and some days 18-20, all depended on when the missus was home. The ST9420C1008 that comes with the RF2 only seems to allow a timer of on or off and the wireless stat just acts like a tradition wire stat. This feels like it might be an upgrade from the current UP2 but a bit of a downgrade from the CM927 of the old house.

Any advice or suggestions? I have tried contacting Honeywell directly but they have not responded in over a week.
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Could swap it out completely to nest/hive or plenty of other options, the hive will use the same backplate as the up2 clock so fairly easy to do it yourself without confusion. That will also give you the option to set (I think) 6 on/offs a day plus your temp control & obviously ability to use it off phones etc.
If you want to set different temperatures through the day then fit a programmable room stat.
Leave the UP2 in place and wire the receiver for the stat from that.
Call me old fashioned but I'm not ready for the hive yet. I see little point in paying over £250 for a system that will just allow me to control the massif via my phone. I know it can do a lot more than that, but I'm just not ready for that.
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Ok. I think I'm going to go for the CM927 option as this seems to provide me with far more control over temp in our house, plus I know how to set it up etc as I installed it in the old house. However, in the old house installation was easy, I disconnected the wires from the old analogue timer and did a straight swap of wires for the wireless relay.
My question is now, does anyone have any tips etc to fitting the CM927 in place of the heating control portion of the UP2. I'll be able to figure it out once bought, just trying to assess the ease of the installation prior to purchase.
The Sundial RF2 Pack 2 has the same facilities as the CM927 - in fact it has more as it incorporates a HW programmer.

The Pack 2 User manual is here and Installation Manual Here
But reading all the manuals it doesn't have the facility for setting different temperatures on different days of the week? Granted, that requirement comes straight from the missus. But being able to switch between 2 or 3 different temperatures through out the day has been very good over the years :-S
Easiest way to wire it would be to take a 4 core wire from the timer to the thermostat receiver. L-N-E and heating on (SL).
Mount the receiver next to the timer. Remove heating on wire from the UP2 back plate and stick it in a choc block then take your receiver SL from there.
Does that make sense?

Im not overly familiar with honeywell kit. If the receiver needs a common as well then link from live to common.

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