Elemex immersion heater power consumption

Black_Widow

We have an Elemex 2/2.85kw 220v immersion heater installed in our hot water tank. When in use the power consumption rates (owl electricity monitor) are as follows:
Bath on only - 2.2kw/h
Sink on only - 3.3kw/h
Obviously a small portion, maybe .100, of that is the house ticking over.
I'm just curious if that seems correct because my basic and very novice thinking would have been that the bath element would use more kw/h than the sink element. Is it wired the correct way around?
Could be just me being blatantly stupid as to how elements work, hopefully not.

Edit: Also may I add, with the bath setting on for 1 hour, we don't get anywhere near enough hot water for a bath. Maybe just enough for my 7 year old to be covered to the waist. Maybe I'm just not leaving it on long enough?

cbrlover

I would think it is wired wrong. Get a competent electrician in and they will sort it in minutes.

Ya sounds like its just a matter of switching around the brown and black wires behind the immersion switch. Common mistake

Bruthal

Black_Widow wrote: »

We have an Elemex 2/2.85kw 220v immersion heater installed in our hot water tank. When in use the power consumption rates (owl electricity monitor) are as follows:
Bath on only - 2.2kw/h
Sink on only - 3.3kw/h
Obviously a small portion, maybe .100, of that is the house ticking over.
I'm just curious if that seems correct because my basic and very novice thinking would have been that the bath element would use more kw/h than the sink element. Is it wired the correct way around?
Could be just me being blatantly stupid as to how elements work, hopefully not.

Edit: Also may I add, with the bath setting on for 1 hour, we don't get anywhere near enough hot water for a bath. Maybe just enough for my 7 year old to be covered to the waist. Maybe I'm just not leaving it on long enough?

As said, bath and sink are mixed up. When you have it on sink, the bigger bath element is on. You could leave as is, so sink is actually bath, or swap brown and black behind switch as already suggested.

Black_Widow

Thanks for all the replies and the confirmation of what we thought was wrong. For the minute we are just using the switch in reverse but at least we know it's a very easy problem to fix.

Cheers everyone for the help.

Chief Eng

I'd say you have the best idea, you know the story so just leave the switch as is! If you ware to have a go switching the wires - It might be easier to open up the switch and swap them there. Fitting wires securely to the element is tricky and one of these jobs you need to be fairly competent to start. Leave it be though if you spot the terminal screws have been damaged by the last person at it.

RE: you second question...
Heat rises so your immersion will heat the water above it, to the setpoint of the thermostat (inside the cover of the immersion). A common size for a bath element is 27" (686mm) long.

To heat 10 L of water by 50 deg c you need about 0.6 kW Hours

Not sure what cyl size is but a lot of bath elements positioned at the top of the tank will be trying to heat up maybe 70 L. (4.2 kWh) So if your starting at 10 deg from the attic header tank you will need allow at least 1.5 hours (say 2 hours) to get up to 60 deg.

mikehammer67

Chief Eng wrote: »

I'd say you have the best idea, you know the story so just leave the switch as is! If you ware to have a go switching the wires - It might be easier to open up the switch and swap them there. Fitting wires securely to the element is tricky and one of these jobs you need to be fairly competent to start. Leave it be though if you spot the terminal screws have been damaged by the last person at it.

RE: you second question...
Heat rises so your immersion will heat the water above it, to the setpoint of the thermostat (inside the cover of the immersion). A common size for a bath element is 27" (686mm) long.

To heat 10 L of water by 50 deg c you need about 0.6 kW Hours

Not sure what cyl size is but a lot of bath elements positioned at the top of the tank will be trying to heat up maybe 70 L. (4.2 kWh) So if your starting at 10 deg from the attic header tank you will need allow at least 1.5 hours (say 2 hours) to get up to 60 deg.

a competent electrician will know that's the wrong way to do it

Chief Eng

Thanks for your input hammerman.
How about letting us know the best way?

mikehammer67

switching the wires at the heater is modifying the appliance unnecessarily

(or 2 wrongs to make a right in laymans terms)

they should be swapped at the switch

Chief Eng

Fair enough Mike, good point.

I was allowing for the chance that the switch had become harder to get at than the immersion.
Can happen with a badly fitted replacement cylinder / Solar Installation or the like - you get a pipe placed too close to the switch.
So you need to be Houdini to get a screwdriver near it! So I said "it might be easier"

2011

Chief Eng wrote: »

I was allowing for the chance that the switch had become harder to get at than the immersion.

This can be the case sometimes.

I would recommend installing the immersion switch outside the hot press mainly because it reduces the chances of accidentally leaving the immersion on and running up a bill comparable to our national debt
It also makes it easier to connect / replace.

mikehammer67

it's been a rule obviously for quite a while that the switch goes outside

2011

mikehammer67 wrote: »

it's been a rule obviously for quite a while that the switch goes outside

Often not done.