So 4 hours night time at 3KW immersion is the same as 6 units per day. I use it for 30 to 40 minutes daytime mostly which is max 2 units. 4 units per day is 80 cent times 60 days = 48 euros per bill more than I use in a one bed apartment. Add your 40 minutes fan heater and towel heater, the fact that there are two people, that you probably use the washing machine more often than I, you have a drier. You would be well over a a hundred per bill more than mine. My winter bill is 180 and I'm on the cheapest provider as I move every year. I think your bill is correct given the information posted.
1) Switch off towel heater
2) Stop using fan heater for 40 minutes (a quick 3 minutes boost warms the place up quickly)
3) Consider using the boost rather than night time heating BUT this could be tricky if you're on a dual thermostat
4) Do you have a dish washer ? If not then you won't have water on demand for cleaning dishes if you change above.
1) Switch off towel heater
2) Stop using fan heater for 40 minutes (a quick 3 minutes boost warms the place up quickly)
3) Consider using the boost rather than night time heating BUT this could be tricky if you're on a dual thermostat
4) Do you have a dish washer ? If not then you won't have water on demand for cleaning dishes if you change above.