MrPotts

I think an electric boiler could be a good option for replacing a gas boiler but only if the government/energy suppliers reduce the price of electric to gas price level. The system we have at present for electricity pricing is a scandal!

interesting video discussion here……

When I started the journey a few years ago all I wanted was to replace my old analogue Honeywell room stat with a new digital room stat. I then succumbed to the clever marketing and online youtubers extoling the virtues of Hive, Wiser, Tado, Nest etc only to spend the next 2 years and 3 winters trying to get the heating to work how I wanted. I've now given up and gone back to a single room thermostat albeit the Drayton Wiser room thermostat.

Yes, its how Wiser works. I use the Drayton Wiser integration in Home Assistant which directly interrogates the hub. For those that aren't familiar with the Wiser system the heating cycle works like this (I think Evohome works the same way, it looks like it from the OP's graphs)..... Configured within the hub is the boiler type so gas boiler, oil boiler, electric boiler or heat pump. Mine is configured for gas boiler which means that the Wiser hub divides an hour into six 10min segments. From cold in order to reach target temperature the Wiser hub will set a heat demand of 100%, this means in a 100% heat demand situation Wiser will request the boiler to fire for the full 10mins and will continue to do this for each subsequent 10min segment until the actual temperature and target temperature get closer. The heat demand gradually reduces as target temperature gets closer so an 80% demand fires the boiler for 8mins, a 60% demand for 6mins etc. until the heat demand reaches 20% which is the lowest I have seen. There must be some clever algorithms within the Wiser software that takes in all the different temperature setpoints and actual temperatures from all the thermostats to come up with the heat demand percentage. Sounds complicated doesn't it! This is why I have replaced almost all my radiator thermostats so the hub now only takes information from one room thermostat.

Exactly that. It’s pretty annoying for Wiser to be close to temp with say a 20% heat demand to then fire the boiler for 2mins in every 10min cycle. At least with the “oil” setting Wiser will fire the boiler for 4mins but this is either a 20min cycle. I have removed all the independently controlled Wiser rad stats as they just add an unnecessary complication.

No, I can monitor the hub directly and it is the hub forcing the cycling.

Thanks for the info but I have already tried setting my Wiser hub to oil boiler but the setting doesn’t work, the boiler still fires 6 times an hour. I’ve reported it to Drayton tech support.

The boiler is being cycled 6 times an hour by Evohome. It is not the boiler initiating the cycle. My Drayton Wiser does exactly the same. I think you can change the cycling frequency within the Evohome settings.

Vertical radiators are notoriously poor at space heating, maybe swapping the radiator for a conventional convecting radiator might heat the space better. Have you calculated the heat loss of the room?

Most people won’t replace a working boiler so the only time that anyone would vaguely consider a HP is during a breakdown but who wants to wait 3+ months for heating to be restored when a new boiler can be installed in days. Surely a better solution is to reduce the price of electricity (BUS grant can be used here) to be the same as gas and install electric heating either by boiler, in place where the old gas boiler was, or panel radiators. By 2030 all our electricity will be provided from renewables anyway, according to Ed, so the subsidy won’t be for long. 😀

I wouldn't accept all the ugly external pipework, as soon as the installers said how it was going to be done I would have called a halt to the work. Unfortunately my house would need a similar install hence I won't be getting a heat pump anytime soon.

You only need a blending valve if you have UFH and radiators unless the radiators are sized for low temperature flow.

I wonder if this can be done with a smart TRV during the initial calibration. Just place a thin spacer on the pin, attach the TRV, run through the calibration and then remove the spacer. I wonder if the TRV will then remember to stop just shy of closing completely.

At the moment my gas boiler is igniting 6 times an hour controlled by my Wiser controls so maximum burn time is 10 minutes. I have tried to adjust the ignition to 3 times an hour but the setting doesn't work despite the Wiser hub confirming it is set correctly in the configuration. I have an open support ticket with wiser on this.

How close are you to the local weather station where the control gets its information from? The further away you are the least accurate the information will be. Better than nothing but not as good as having an outside thermostat on the wall of your house.