Heres a top tip that might save you money. If you have a fairly modern combi gas boiler. Check to see whether it can have a weather compensator or OpenTherm controls fitted. Its generally a fairly straightforward installation. These can save you up to 10% on your gas usage for heating. The weather comp detects the outside air temperature. On cold days it will allow the boiler to run at max rate, but on warmer days it dials back the temperature to the rads, meaning you use less energy. Opentherm, like the Nest 3rd gen uses a similar system, but in this case it detects how close to the target temperature the room is. So for example if you want your house 20C and the room is only 10C then the boiler will heat at max rate, but as the room heats up the Opentherm controls starts to modulate the output of the boiler down, saving you a lot of energy. This might help some of you save a bit this coming winter and even if you dont fit these controls, my advice is to look at what the temperature of your boiler is set to. For example in my house, the factory set radiator water temperature is 68C. Last winter I started turning it back and seeing if my house still heated adequately. I found out that I could actually turn it back to 53C and still heat my house without any issues. Imagine how much gas that saved over an entire winter by reducing the output by 18C, plus if youve got a condensing boiler that will keep it running at its max efficiency for longer in each cycle. i hope this helps a few of you save a bit this winter
Thanks for the tip, but why does it only work with combi's? Isn't it just a version of an external temperature optimiser that commercial/BMS controlled heating systems have?
I don't pay by direct debit. I submit meter readings every month and they bill me for exactly what I have used. It works for me. I switched off the gas boiler 3 months ago and only use a little gas for hob cooking. My aim is to use little energy during the summer to help offset higher winter costs. If you make an effort its surprising how much can be saved.
This is exactly how my gas and electric is done too. It works for me, and has done for many years. The only changes have been the installation of a smart meter so I don't actually submit my readings now. This actually caused my costs to reduce, which was a pleasant surprise. I know for some the idea of low costs in the summer, which then jump hugely in the winter months would seem mad, but somehow it just works. And it means I'm only ever paying for what I've actually used.
It’s not that it only works with combis. Modern Combi boilers are wired to only use the weather comp or opentherm for heating, leaving the domestic hot water untouched, so I can safely recommend it. Its a little trickier with systems that use a stored hot water tank, as if its not wired correctly then theres a risk that the cylinder wont be heated correctly and you could get a legionnaires risk. So im not happy just giving a blanket recommendation for non combis, although with a lot its still possible. With regards to commercial optimisers, then yes, the weather comp is exactly that but for domestic appliances. Opentherm is different, it is a load compensator, which uses the room temperature and target temperature and calculates the most efficient heat curve. Nest is very clever as i believe because it is wifi enabled it also adjusts its curve based on information from weather stations, so its a hybrid of the two. Hive although smart does not support opentherm and neither do Worcester boilers I believe.
I wish it were that simple. General policy may be dictated (yes I used that word on purpose) from No.10, but there's so much of our lives controlled by the local councils, which invariably are full of 'little Napoleons'. Whether the local seats are Tory, Commie, or Monster-raving-loony, I don't think has much bearing.
If you turn the boiler off you won't get either! I'm wondering if @mgbman uses an immersion heater for hot water, which would be far more expensive than via the boiler
We have a condensing non combi boiler, We have an immersion, we use April to November, foam lagged cylinder, In a well insulated cupboard, it's full of spare pillows Heater is on a timer 1 hour a day Works ..for baths, and washing, Other hot water is heated in the machines,or shower..
Fair play, if you can get enough hot water from 1 hour of immersion a day to run baths and to wash, but comparison on a typical gas v electric unit rate is at least twice as expensive for electricity?
True, the leccy oven probably costs double what the gas hob does.. The electric is always the largest part of the bill.. My neighbour has bought and electric pie maker, to cut costs... He made a gooseberry pie from berries I gave him .
Per KW electricity is more expensive. However an immersion heater is a direct heat source, so if one hour is sufficient to heat enough hot water then you are at least heating only what you require. Using the boiler you have to heat the water in the boiler, then the water in the primary pipework, then the water in the cylinder coil, then transfer that heat indirectly to the stored water. So the boiler would need to run longer than one hour, and of course as well as using gas, the boiler needs electricity to power it, the controls and the pump. The advantage of this is that you are heating the entire cylinder, not just the top third as you would with an immersion heater, but if you arent actually using a full cylinder every day then I guess there is an argument for using the more expensive immersion. Just to throw a spanner in the works, the boiler will heat the cylinder to a higher temperature, which means in a well insulated tank you might only need to run it every other day instead of every day for the immersion. I guess the only way to know for certain would be to experiment alternating one way to the other and calculate the useage from the meters. But who can be bothered to do that? Actually probably me as I have no life.
You are not alone. I have compared boiling enough water for two mugs of tea in a conventional jug kettle, compared to the same amount of water in a steel kettle boiled on an induction cooker hob. Difficult to tell exact kW ratings for the kettle or the hob, so I based it on the number of pulses the meter took to reach boiling point for each source. The conventional jug kettle took far less pulses to boiling point. Is anyone still awake..........?
Re efficiency.... Gas v elec.. Heat is also wasted in a boiler with an amount going out through the flue..and the other losses you point out.. Also the same with a kettle..
The only efficiency I've noted is the instantaneous on/off response and no power usage when pans are lifted off the hob plates. I try to alternate between the four hob plates as I'd assume a failure would be unrepairable ?
But also remember that a resistive electric element immersed in water is pretty inefficient as well. Most forms of electric heating (air and water) was designed when electricity was cheap as chips, and so abundant that you were offered it at half price if you would use it overnight/off-peak.
