Hysteresis Setting For New Drayton Room Stat

I'm after a bit of advice from the experts. I've just fitted a new Drayton Mistat N110R wireless room thermostat for my parents combi system. I'm not keen on TPI/TP, so set the stat to run as a normal on/off stat.

On these stats when you select it to run on/off, it gives you the option of having hysteresis which you can set at the level you want. The standard, default hysteresis setting that's programmed into the stat is 0.5 degrees C. Should I leave it set to this? Or should I set it to something else?

Can anyone also explain exactly how hysteresis will make the stat run, as I'm unclear about how it works. For example, if the set point is 18 degrees and the hysteresis is set to 0.5 degrees, will the stat cut out at 18.5 degrees, and come back on when temp drops to 17.5 degrees?

Many thanks for any advice.

Bump!

Anyone?

I would assume that, if you set the temperature to 19C, the stat will turn the boiler off when the temperature reaches 19C, and turn it back on when it drops to 18.5C.

Why don't you just fit it and see what happens?

Why don't you like TPI/TP? I've been using a TPI stat for over 10 years and can't fault it.

Thanks for your reply, Mr Hailsham - and apologies for my late response. Yes, that would make sense, re. the hysteresis. The new stat seems to be functioning well.

TPI/TP seems to cycle the boiler a lot. Maybe I haven't given it a chance, but all my old stats have been on/off and like the predictability of that way of working. I'm sure TPI would save money, but doubt it would be more than a tiny percentage of my overall bill. In the long run, the regular cycling of TPI may cost more in increased boiler wear and early demise.

Thanks again.