MrPotts

We are spending billions on renewable energy whilst at the same time paying renewable energy companies millions to turn the supply to the grid off whenever the wind is too strong or the sun to bright. This is all added to our energy bills!

If electricity prices were the same as gas prices then would the case for an expensive heat pump diminish in favour of a direct replacement of a gas boiler with a much cheaper electric boiler? Then there would be no need to change radiators, pipework or the HW cylinder and no need to give away £7.5k of tax payers money per install. In fact the money could be used to provide the electric boiler for free!

What I don’t get is how can it be said that spending 10’s of thousands of pounds on solar and battery so that you can power a heat pump that also costs thousands of pounds is cheaper than keeping your gas/oil boiler. It would likely take a lifetime to recover the initial investment wouldn’t it?

Considering that Google will not be releasing the gen4 Nest in Europe I’m not surprised Google are removing other elements of the system. Below is a quote from Google Nest Community Blog………. Nest thermostat updates for Europe Heating systems in Europe are unique and have a variety of hardware and software requirements that make it challenging to build for the diverse set of homes. Therefore moving forward we’ll no longer launch new Nest thermostats in Europe. With our Google Home platform approach we are enabling a wide range of established smart thermostat companies to build energy devices and experiences that cater to these markets. The Nest Learning Thermostat (3rd gen, 2015) and Nest Thermostat E (2018) will continue to be sold in Europe while current supplies last. These models will continue to receive security updates and you can control them via the Nest and Home apps. https://www.googlenestcommunity.com/t5/Blog/Support-changes-to-our-earliest-generation-Nest-Learning-Thermostats/ba-p/713068

Do you want one zone upstairs and one zone downstairs or do you want a zone per room? Its better to have no zones with a heat pump.

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. 😀