Can You Turn Off TPI Function On Honeywell CM927 RF Stat?

[Whitespirit66]

Recently installed a Honeywell CM927 for a customer who has a Baxi 80e combi. Found it very difficult to explain to him the way this stat works, especially TPI. Temp overshoots set-point, which he doesn't like.

Worst thing is the boiler firing up every 10 mins which is noisy because of it's location and he complains that it's using gas unnecessarily. Also complained about wear and tear of constant firings.

Can you turn off the TPI setting on these, so it works more like a normal stat? I see in the parameters table of the instructions, you can either disable or enable 'optimisation' - not sure if this disables TPI?

I'm going to stop fitting these stats, as they confuse people and are difficult to explain the way they work. I notice the Danfoss TP7000RF lets you turn off their version of TPI (chrono-proportional control).

Customers!

 

[Galoka]

No, AFAIK you can't turn off the TPI, though you can reduce it to 3 periods per hour.

'Optimisation' is something different, that relates to the Optimum Start feature where it tries to work out the best time.to turn on to get the house warm at the right time.

I almost fitted one, until I realised you couldn't turn it off. I don't like the whole TPI thing anyway. It''s a good idea in theory (and maybe with responsive enough system it can work ok), in reality it seems to lead to a lot of switching on and off , with the concomitant wear on valves, pumps etc. without any real benefit to users.

Certainly in our house it would be a bad idea I think, as we have a lot of thermal mass, the system is quite large and meanders around our old Victorian house, the boiler is a long way from the furthest rads . !0 minutes firing and some bits would hardly be warm before it turned off.