Electric boiler: help!

[SharkAttacked]

We have just had to move to a new rental and have an electric boiler. Can anyone advise on the best way to use it as cheaply as possible. It runs both our hot water and radiators.

It’s an Aztec 11KW electric boiler and we have no idea how to programme it. Is it better to keep it at a constant temperature or keep turning it on and off?

Bump for the morning crowd

I would definitely only run this when you need heat. (Though you should run it for a little bit every day in winter if you can,to fend off damp). It's heat pumps that work better left steadily on low.

It's going to be expensive I fear, electric costs so much more then gas and although electric boilers are more efficient than gas boilers, it's nothing like enough to make up the cost difference.

Thankfully we will only be in this house for one winter (in between buying) so we’re happy to absorb some additional costs. I was under the impression it’s better to keep the water tank topped up rather than turning it on and off-is that correct?

With the heating is it better to set it on a timer or just turn it on and off when needed?

This needs to be moved to Property/DIY where it will get lots more traction, OP.

Moving it now

It's better to only use it to heat precisely the amount of water you need and then use it immediately and not keep it at high temps in between.

Things that might change that is if you are on something like a switched tariff. In that case it would probably be best to heat the tank during the cheap period. But of course it depends on how well insulated the tank is, as if you heat it during the cheap period then wait 7 hours to use it you might have lost a lot of the heat.

Finally remember that in winter, when you heat the tank and the water cools, where does the heat go ? And the answer is, into the house. So it is not entirely wasted.

This is a bit like LED bulbs. In winter if you replace say a 40W standard bulb with a 5W led bulb, but that means 35W that you have to find elsewhere to heat the house (hopefully from gas). In summer that 35W of heat output would be truly wasted as you don't want the house hotter. The same goes for your boiler. Escaped heat in winter has value as it heats the house. In summer it has no value.

All this is a bit hardcore, so may not make any sense :)

The other thing I would do is make sure you learn to read the meter and how much it is actually costing you. Then you won't get a massive bill out of nowhere. You can also experiment with different heating strategies.

It might not be anywhere near as expensive as you think it might be if the flat has a very good energy rating. New flats that are electric heated tend to have this.

@GasPanicWe have a smart meter so can track usage thankfully. It’s an old house rather than a flat so I am expecting to have a cold winter unfortunately, so just want to get to grips with it now. My main worry is the heating more than the water as I do like a warm house and WFH. Would it be worth setting the thermostat to a specific temperature for the heating or just turn it on/off as needed?

If I was wfh I would keep the costs down by setting up a home office in the smallest room possible and having a small portable electric heater in there, and not running the radiators at all (this is if you have criculated water for the radiators, if they are direct electric then you can just turn them off for each room apart from the one you work in).

In a small room even the heat the PC and monitors generates is quite a bit and can help keep it warm.

I would probably try to keep that one room as warm as possible with secondary glazing film if you don't have double glazing, plus a draft excluder under the door. Then you can hole up there for the winter just going out for the odd cup of tea !

For the evenings a heated throw on the sofa can keep you warm at much lower cost than heating the whole room, and an electric blanket for the bed warms it much more cheaply than the radiators. You can use a heated throw for both the sofa and for warming the bed if you don't want to lay out for both.

What electric tariff are you on?

I haven't had an electric boiler but do live in an all electric property.

There are usually tariffs specifically for this. Ideally something like economy 10 or Scottish Power do a total heat total control tariff but think that is region specific. Very few suppliers have it unfortunately.

High draw like a boiler needs to be on the cheaper rate.

With economy 7 this is all overnight usually midnight to 7am (or 12.30-7.30am).

Economy 10 splits the times so you get a bit in the afternoon (1.30-4.30) and then 8.30 to midnight and 4.30-7.30am (can vary by half an hour).

So this is better for being able to boost the temperature up for the times you are going to be in.

Do you have a wood burner or any other way to heat the house? Unfortunately electric is expensive.

I’ve checked and we’re on economy 10 so that’s a positive, would you all bother with buying an oil filled electric portable or just use the radiators?

Already looking at glazing film and an electric blanket too. I already have the thickest blanket known to man for my bed in the winter so that should be fine!

So with the heating, should we bother setting the thermostat to a specific temperature or only turn the heating on when we need it during the off-peak times?

It will be extortionate to run on peak times so I'd try and coincide the times it is on with the low rate.

Ask your supplier for the times as they vary very slightly. If you set it so it warms up late afternoon (say 3.30-4.30 - some finish at 4 so important to check) then hopefully that will warm the house up enough for early evening.

Then put it back on 8.30-9.30 so warm for bed and something like 6.30-7.30 in the morning.

The downside of economy 10 is the peak rate is higher. If you can also time your showers to the cheaper times, dishwasher, washing machine etc you'll get the most out of it.

If you have to run heating outside of the office period then probably better to heat one room with an oil filled radiator. They are 1.5-2kwh so on (at a guess based on most) 35p per kWh it can soon add up.

You are probably nearer to 12p a kWh off peak.

There will be a bit of trial and error so good you can keep track of your usage.