I have moved to a new house that has an electric shower and my bills are so much more than my previous house of teh same size. I use the same goods- cooker, dryer, washer, fridge etc as I did in my last house and use same supplier. The only thing that's different is the electric shower. Our household uses it on average about 90 minutes per week. Could this be a major factor? I presume its like boiling a kettle as it has to heat cold water immediately Any thoughts on running costs for it?
Assuming it’s an 8.5kw shower ; assuming a mid price of 17p per kilowatt hour. Your 90 minutes will cost you 1.5 x 8.5 x 17p = 217pence per day. If your shower has higher wattage or your tariff is higher it will be more. So over a month (30days for this example) you will be paying £65 for shower alone.
Nice sums, slightly out though. 90 minutes per WEEK not day. Correcting that would give about £10/month or £30/quarter.
thanks for that, so not as much as initial workings......still shows it isnt cheap to run, and it has to be run on full power as doesnt seem to get hot on the lower ones, maybe its inefficient and struggling to heat
The heating itself is not "inefficient" as all the power will be converted to heat and almost all transferred to the water. You would be better off with a lower cost water heating capability such as a "pellet burner".
The fact that your shower is heating the water 'on the fly' means that all the energy is going into the shower ... almost none of it is being wasted through 'heat leakage' from the pipes or from the storage tank. Were you to be using a hot water immersion tank to heat your water for your shower, you'd be losing heat from the tank (especially since most immersion heater tanks are appallingly badly insulated here in the UK) and from the pipes going from the tank to the shower. Firstly you'd be wasting water running the old cold water in the hot water pipe until the hot water reaches the shower, and then you'd be wasting energy as the pipe full of hot water just sits there getting cold again. Bottom line is that if you're going to have a shower with electrically heated water, then the dedicated electric shower you have already is the most efficient from an energy consumption point of view.
That might indeed be more cost effective, but it is definitely less efficient "from an energy consumption point of view", because in order to use those off-peak electricity rates you would need to use a hot water storage tank, and, as I stated above, there are lots of heat losses from that, and they make it less efficient.
New house so possible. say the immersion heater is on all the time, or something else is on all the time?
There are four versions of the T80si - 7.5kW, 8.0kW, 8.5kW and 9.5kW. There should be a label on the underside of the shower giving the rating. If not, its inside the shower - helpful, not! If you are someone who likes very hot showers then your electricity consumption will, inevitably be higher and you will have to pay more. I would say that £10 a month, or 33p a day does not seem expensive.
If the shower is quite old and you are in a hard-water area, the element may be scaled up which means you have to run it on the higher setting for the water to reach a comfortable temperature. Try descaling the shower head if some holes are scaled up.