Issue with Megaflow DD170 Electric boiler with 2 switches and eco7

DavidPurfleet

Hey Guys,

First time Forum user, sorry in advance if i brake any rules by posting this or smth..

I've recently moved to a new 2 bed property where all the appliances are running in electricity.
I've received my first bill for electricity for 2 weeks they've charged me with £120.

After that I've started investigating to find out what eating the electricity and found out it is the boiler that is draining %90 of the electricity in the flat during the day.

At first I've been using both switches next to the immersion heater ( Top - Booster , Bottom - Off peak ) and because of that the bill seems to be extremely high for 2 people who only use the showers once a day and don't use heating in the flat because we have a great heating isolation. Washing machine and dishwasher used during off peak also.

I've also bought (Geo Minim Electricity Energy Monitor) to check the electricity usage of every appliance at the household .

Long story short I've realized that when i turn the Off peak switch on the immersion heater turns on straight away but it should only start operating on Off peak time with economy 7 meter at my flat.

There is no timer next to the switches or immersion heater. Just 2 switches. So I'm assuming the boiler should be programmed with off peak switch to start operating after 12am but it clearly doesn't .

Would changing the off switch with a timed switch solve the issue ? Please help me out any advice matters !

Thanks .

Rubidium

Have you checked your consumer unit to see if there is a timeswitch?

DavidPurfleet

I'm afraid there is no consumer unit in the room where the boiler is , neither somewhere else at the flat . Otherwise i would just change the settings on it to start operating around midnight.

Rubidium

DavidPurfleet wrote: »

I'm afraid there is no consumer unit in the room where the boiler is , neither somewhere else at the flat . Otherwise i would just change the settings on it to start operating around midnight.

Iwould not expect you to find your consumer unit in the room where the Megaflow is located but you must have a consumer unit (fusebox in old money) somewhere in your flat, so you need to find it and check it tosee if there it has timeswitch to control the Megaflow Off Peak usage before considering fitting any other timer.

Example of consumer unit timeswitches shown here

You also need to establish the exact times that your E7 Off Peak is active i.e. it is likely controlled by your multi-rate meter but you need to check- you can't assume that after midnight is Off Peak.

DavidPurfleet

Sorry I've misunderstood that. I will have a look at the fuse box when i get home to see if there is a timeswitch.

My off peak start from 24:00 to 07:00 i have checked on my electricity meter it changes the tariff at that time and Scottishpower website.

matelodave

Firstly switch off both switches and make sure that the meter isn't registering or at least only slowly. Then find out which switch turns on the heater by checking the meter when you switch it on.

It should be wired so that the off peak switches on the main heating element (usually situated at the bottom of the tank) and that should only be activated during the off-peak period. The boost switch should turn on the other immersion heater and should come on using peak rate leccy.

Just check that the switches haven't been mislabelled/miswired. Have you got two fuseboxes, one peak and one off peak, if not then you should have a timeswitch or heater controller which turns the off peak heater on during off peak times - something like this https://www.bristol.gov.uk/documents/20182/34400/Hortstmann%20Economy%20Seven%20Quartz%20Water%20Heater%20Control.pdf/bba8a1d0-7b62-41fa-86d5-970d82b6809a

D_M_E

When you say boiler, do you mean the hot water tank with the 2 immersion heaters in it, or do you mean your flat has electric heating and no gas supply?

For a couple of showers a day, just turn on the top immersion heater for half before the first shower then each one has their shower then turn it off, no need to turn on the bottom immersion just for 2 showers a day.

For washing dishes and the like it's far cheaper to boil a kettle and the hot water from that than turn on the immersion.

If you know where and which meter is actually yours, have you checked that the serial number(s) on the bill correspond?

Are you on the supplier's cheapest tariff or have they put you on their expensive standard tariff?

DavidPurfleet

Hey matelodave,

Thank you for you reply.

As I mentioned in my first post I have (Geo Minim Electricity Energy Monitor) plugged to my meter outside my flat that shows Live data for my electricity meter and i have a display in the kitchen.

If i turn off both switches the boiler is off ( no electricity consumed ) .

1) Then Top switch is wired to top of the boiler so it should be booster and when i switch it on the heater turns on and i can see on my display the electricity is being consumed straight away. So it works fine.

2)The bottom switch is wired to bottom of the tank so it should be off peak switch that should heat the water overnight with off peak tariff. But when i switch it on i can see on my display that it start heating the water straight away same as the booster switch.

I do have only one fuse box i will try to describe it when i get home .

My heating system is separate from the boiler it's controlled by hand and plugged in electric socket in the living room and corridor but i don't use them and they are off. That being said my boiler only controls the hot water for my taps .

DavidPurfleet

Hey D_M_E ,

Sorry i'm quite new with the terminology for all of this.

Yes i have hot water tank with the 2 immersion heaters and 2 switches .

And my storage heaters are plugged to sockets next to it and runs on electricity.

i'm trying to get the heater to work during the night as it should be on eco7.

Also the meter readings are correct I have supplied those to my new supplier.

Also as mentioned before i have live data coming to my display from the meter.

DavidPurfleet

Rubidium,

I have checked my consumer unit and i'm afraid there is no digital time switch.

But there is a normal switch that is label E7 HEATER SWITCH separate to immersion heater switch and it was switched ON all the time.

It gives power to switch by the immersion heater lower one for the off peak , because when i've switched it off the off peak switch by the heater was not responding.

matelodave

Do your storage heaters turn on and off at the appropriate times (ie during the off-peak period). If so, then you should have a seperate off-peak circuit which feeds the storage heaters and it should also feed your off-peak feed to the water heater.