Another energy one... Combi boiler

[Tulipdays]

Another energy one as I've recently moved into a freezing cold flat and figuring out how it all works whilst quietly shitting myself about the energy price hikes.

I have a Glow Worm combi boiler, it appears to have no timer or programmes, just hot water and heating temperature control. I've had a very basic fixed thermostat installed in the hallway but now very frustrating that this also doesn't have a timer (another thread). A few questions I have:

Should/could I turn off the hot water mode overnight to save on energy consumption?

Ditto for turning off heating mode overnight?

Am I better off with getting a portable thermostat and one with a programmeable timer etc?

I'm getting a smart meter installed next week - what difference is this actually going to make?

Anything else I should be doing to ensure I'm not burning money (literally)?

I'm fuming at myself for being so clueless

If it's a reasonably modern glow worm you should be able to get, from glow worm, a programmable, movable, controller. From this you can adjust the temperature for different times, eg 13°C overnight, 17 in the morning, 14 during the day and 18 in the evening. A combi boiler only heats hot water when you need it, so switching the hot water off at night will save you no energy whatsoever. A smart meter will also save you nothing, it will just make you aware of what you're using and what appliances use the most power and possibly make you realise that boiling a full kettle for 1 cup of tea is wasteful and expensive! Our controller also adjusts the flow temperature to the rads depending on outside temperature, but you'd need an outside temperature sensor as well for that.

I've not looked at the range of controllers that are compatible with glow worm, but you can possibly get one that works via an app so you can adjust heating timings from your phone.

A combi boiler only heats hot water when you need it, so switching the hot water off at night will save you no energy whatsoever.

Agree with PP on that. However, some combi boilers may have a "comfort" or "pre-heat" mode (or something along these line) where the boiler is heating up something inside (heat exchanger?) even when there is no demand for hot water. This means that when the taps are turned on, hot water can be delivered quicker. If your boiler has this mode, you may want to make sure it's switched off. But I'm not familiar with Glow Warm boilers and don't know if they feature something like that.

if you have a wall thermostat, and it works, you can easily change it to a programmable stat that includes a timer, and will change the temperature setting according to day of week and time of day.

For example:

Monday to Friday, turn on at 7.30 with a target temp of 20C
At 9.00 turn the temp down to 16C

At 5pm turn up to 20C
At 23.00 turn down to 16C

Saturday turn up at 8.00 to 20C
At 23.00 turn down to 16C

etc

The stat doesn't actuall have an "off" and "on" setting. It just changes the target temperature. If the room is above this temp, it will not turn on the boiler. 12C is common for unoccupied houses in winter as it protects from damp and freezing pipes.

You can if you want get smart ones that enable you to turn the heating up and down when you are on holiday in Marbella. Some of them need to have an active internet connection. I can't be arsed with all that.

Any heating engineer or experienced electrician can change a wired simple wall stat for a programmable stat.

Wireless ones are available if you don't mind them costing more and going wrong more often

The boiler doesn't know what's connected to it, it just gets a "turn the heating on" or a "turn the heating off" signal.

Examples, old and new, see pics.