Best controller for my Worcester Greenstar 34CDi

[techrigger]

This is my first post on the forum...i have been reading it avidly over the last few days and realise it is a great source of information...but I have searched in vain for an answer to my controller dilemma.

I have an existing Honeywell CM67NG wireless controller which has served me well for 2 years...apart from the occasional ludicrous three hour early optimisation!!!

I also have my installer recommending either the WB DT10RF optimiser or the DT20rf wirelss thermostat.

I have now installed the CM67NG , and noticed that the boiler modulates the burner to very low flow rate and temperatures at first then ramps up after say 2 or 3 minutes..is this normal and would it be safe to assume that this is better for cost and fuel savings(My previous boiler did the opposite and started flat out and modulated down). Also it does get cycled by the CM67NG and this alters as the house gets warmer..as it is supposed to do...it also learns and optimises fdor all the set points not just the start temperature.

Simple question....cost not to be considered...

Which is the better solution for my boiler efficiency...the CM67NG or the DT10rf.....im not concerned about the water pre heat as i can use the eco button to control that myself.

Thanks in advance ...

 

[Agile]

Far better to start low and increase.

Just read all the problems people have with Vaillant which start on near full power and get too hot and turn off!

Tony

 

[techrigger]

I have now tested the honeywell for three days and have set it as an oil boiler, which seems to suit the worcester...so it cycles for only 3 times per hour instead of six and has a minimum on time of 4 minutes this seems to give a good balance between using the boilers flow modulation and the honeywells cycling modulation and optimising feature, no overshoots yet and the house is now feeling like it should with no short cycling. Would it be worth me installing the DT10rf optimiser ...would it increase efficiency further ...and is the water preheat timing a real money saver or not....all thoughts and comments appreciated...id like to get a definitive view on the CM927 v DT10rf optimiser question...when using a Worcester combi