Most energy efficient way to run OSO 210Direct water heater?

[SupMo]

I am wondering what the most energy efficient way of running this OSO 210 Direct water heater is? currently it is costing a fortune to run it on a timer for 1.5hrs a day! so i am wondering whether losing the timer and running it 24/7 will be better?

According to the brochure to heat the full tank properly takes 3hrs (9kWh, so £1.25 a day). However, it's energy loss over 24hrs is 2kW... So would i be better of running it 24hrs and using 2kW + heating the water i use?

I am asking the question as i live in a tiny 1 bed flat and it's costing me a lot of money to heat water for a shower in the morning!

 

[Norcon]

Sounds like its oversized for your requirements though £1.25 per day is cheap IMO.

 

[SupMo]

Sounds like its oversized for your requirements though £1.25 per day is cheap IMO.

I live on my own in a tiny 1 bed flat... spending over £35/month (£420 a year) just to heat water for a shower a day is slightly crazy is it not?

I currently only partially heat the water, so it 'only' costs me £19/month to have a shower a day!

 

[ajstoneservices]

Is the pipework to/from the cylinder insulated, if not, it will add considerably to your standing heatloss. 210l for a one bed flat is certainly overkill.

 

[simond]

3Kw for 1.5 hours is 4.5Kwh. Electricity currently costs around 12p per Kwh, so your costs are half what you have estimated, but I'm assuming you only get a lukewarm shower after 90 minutes of heat.

If you have an economy 7 meter tariff installed, electricity between the hours of 12 midnight and 6am will only be around 4p per Kwh, giving 9Kwh therefore will only cost you 36p a day on this tariff.

Furthermore an OSO 210 direct should have 2 immersion heaters inside (there should be two rectangular plastic access panels fitted on the side), if you use the top one it will heat only about half the water. I assume your bottom one only is connected, meaning you have to heat all the 210 litres each time.

So it might be worth moving the cable to the upper one, and getting an Eco 7 meter. You will then save double the money........