Upgrading thermostat - TPI or weather compensation worth the cost?

ic

I currently have a Worcester 30CDi hooked to a wireless Honeywell CM67.

I often find at this time of year, spring and autumn it can go a bit crazy on sunny days and overheat the house - resulting in opened windows and a waste of heat. I believe my existing thermostat will demand heat right up to the moment the target temperature is reached.

The newer Honeywell CM297 has TPI, a process that seeks to smooth the delivery of the heat by tailing off the demand as the target temperature is met.

My boiler is also compatible with the Worcester FW100 thermostat that has weather compensation via an external sensor. It'll turn up an down the water temperature sent to the radiators in order to compensate for warmer or colder days, and gets the boiler to run in condensing mode for more of the time.

The CM297 is available wireless and costs around £120 and I could fit DIY as I won't need to open up the boiler.

The FW100 is wired, so I'd need to run cable from the boiler in the loft to the sensor downstairs, and then out to the external sensor. The thermostat itself is around £180, and then there's the cost of the cable and time installing it. I'd probably need to get my gas man back to hook it up to the boiler so as not to void my warranty.

Does anybody have experience of either the TPI or weather compensation features with any boiler? Do they offer a more comfortable experience? Would the upgrade to either pay for themselves in the long run through reduced gas use? Does anybody know what cable needs to be run for the FW100?

Thanks

anotherbaldrick

Dont use the weather compensator if you have HW underfloor heating.
The compensator spends it's time modulating the water flow temperature as it anticipates requirements, but the underfloor heating has a thermostatic valve blending the water in the coils down to 50 C or so. The two end up fighting each other.

ic

I don't have underfloor heating, and don't think I'd bother with it in the future - is underfloor heating even compatible with suspended timber floors?