Faulty immersion boiler costing high bill

Gwhiz

So should this thread be re-titled to "Faulty tenant causing high bill"

JAN.1026

silvercar wrote: »

If you are getting some hot water with the switch off it sounds like you have a main source of heating hot water and this immersion is a secondary source. This is how it should be, the immersion is there for back up. If it has been on constantly it would mean that every time any hot water is used and the main source is timed to be off, you would use up loads of electricity in running it. It would explain why you've always had hot water available.

It may be that the tank is small and needs the immersion to provide sufficient hot water.

Whichever way you look at it, you have had the benefit of the hot water and so the bill for its heating is yours.

We had a similar electric expense when we moved home. Unknown to us a plug in a cupboard was unnoticed and left on constantly. We didn't know what it was for. It turned out to be connected to a 500w outside light hidden by ivy. No-one we could claim off and we had to stomach the large electric bill.

Thanks so much..
Ya, as you said so I realized that there is a main boiler in my flat, and that I knew it since the first day I move in, but I have no idea there is an immersion one and no idea there is a switch for it. Even we realise now, the switch is not connected to any obvious machine it the wire just goes into the wall. You just wouldn't know where it is going to .

We have not touched those fuse except from the central one when we did our testing , me and my friend both have no knowledge about electric stuff so we never try to do anything to the fuse.

I don't know if that is relevant but when the immersion boiler was on, there was still no hot water if I switch off the main boiler , and no heating as well. So I really don't know what the immersion boiler is for since we have no source of hot water when the main one is off:/ and that's also why we have no idea that there is an immersion one.

JAN.1026

ILW wrote: »

If you have been getting estimated bill for a while and have now had a reading for the latest one, it is likely that the previous bills were underestimated and now have caught up.

Ya I understand what you mean. But I already have one which caught back the previous bill a month before last month. Therefore the one I had last month is 100％actual one:)

Thanks everyone for trying to help!

silvercar

JAN.1026 wrote: »

Thanks so much..
Ya, as you said so I realized that there is a main boiler in my flat, and that I knew it since the first day I move in, but I have no idea there is an immersion one and no idea there is a switch for it. Even we realise now, the switch is not connected to any obvious machine it the wire just goes into the wall. You just wouldn't know where it is going to .

We have not touched those fuse except from the central one when we did our testing , me and my friend both have no knowledge about electric stuff so we never try to do anything to the fuse.

I don't know if that is relevant but when the immersion boiler was on, there was still no hot water if I switch off the main boiler , and no heating as well. So I really don't know what the immersion boiler is for since we have no source of hot water when the main one is off:/ and that's also why we have no idea that there is an immersion one.

How immersions work (though technical peeps will correct me).

You have a tank of water that is heated by the main boiler during the times the boiler is on. If you use hot water then cold water pipes into the tank, so that the tank is always full. If you use hot water when the boiler is on, the boiler reheats the water in the tank, so it stays hot. If you use hot water when the boiler is off, the water is colder. If you've used the whole tank of hot water, the water is then cold until the next time the boiler is on.

Add an immersion to the equation and whenever the immersion is switched on, the water in the tank is heated to its set point. So if you have a tank of hot water from the boiler, the immersion has nothing to do. If you have used some of the hot water and the boiler is off, the immersion heats up the water. If you have the immersion on all the time, it means you continually have a tank of hot water - every time you use some hot water the immersion reheats the tank water.

If you have only a small tank, it is easy to use up the hot water and so an immersion will heat the replacement water quicker than the boiler.

So the more you had your boiler switched on, the less work there would be for the immersion to do. So in winter when the boiler would be on more, your immersion had less to do if left on constantly.

jennifernil

This all sounds very strange. If the immersion heater element was 3KW it would need to be sitting using 3 KW all day to use 72KwH (units). If it was doing this, the water would be scalding hot all the time.

Yet the OP says they have no hot water even with this switch on, unless the main boiler is also on?

OP.....is the main boiler gas fired?

A wire disappearing into a wall, that you cannot actually see is connected to the immersion heater element, could be going anywhere......even to another flat!

Do all the flats have the "boiler room" above each other?

Aquatronixjenny

silvercar wrote: »

How immersions work (though technical peeps will correct me).

You have a tank of water that is heated by the main boiler during the times the boiler is on. If you use hot water then cold water pipes into the tank, so that the tank is always full. If you use hot water when the boiler is on, the boiler reheats the water in the tank, so it stays hot. If you use hot water when the boiler is off, the water is colder. If you've used the whole tank of hot water, the water is then cold until the next time the boiler is on.

Add an immersion to the equation and whenever the immersion is switched on, the water in the tank is heated to its set point. So if you have a tank of hot water from the boiler, the immersion has nothing to do. If you have used some of the hot water and the boiler is off, the immersion heats up the water. If you have the immersion on all the time, it means you continually have a tank of hot water - every time you use some hot water the immersion reheats the tank water.

If you have only a small tank, it is easy to use up the hot water and so an immersion will heat the replacement water quicker than the boiler.

So the more you had your boiler switched on, the less work there would be for the immersion to do. So in winter when the boiler would be on more, your immersion had less to do if left on constantly.

Correct!

Although if the thermostat is faulty on the immersion heater element (they have a separate thermostat, they don't use the small one on the side of the tank) then the element may be constantly heating the water which would cause the tank to vent and overflow through the F and E tank in the attic. Therefore if it is one of the old elements with no safety cut out button, it may just be on all day?

Get an electrician out to actually diagnose the problem, they should be able to pinpoint exactly what is causing this huge bill, then if it is definately down to faulty wiring then I would write to your landlord asking them for a goodwill contribution towards your leccy bill.

JAN.1026

Aquatronixjenny wrote: »

Correct!

Although if the thermostat is faulty on the immersion heater element (they have a separate thermostat, they don't use the small one on the side of the tank) then the element may be constantly heating the water which would cause the tank to vent and overflow through the F and E tank in the attic. Therefore if it is one of the old elements with no safety cut out button, it may just be on all day?

Get an electrician out to actually diagnose the problem, they should be able to pinpoint exactly what is causing this huge bill, then if it is definately down to faulty wiring then I would write to your landlord asking them for a goodwill contribution towards your leccy bill.

That's what I think so, but I think the electrician from estate agent only find out that the switch which they say is connected to the immersion boiler cause the meter run fast abnormally. Yet, they said it still shouldn't cost that much.

Should I ask another electrician to carry out other test?

JAN.1026

jennifernil wrote: »

This all sounds very strange. If the immersion heater element was 3KW it would need to be sitting using 3 KW all day to use 72KwH (units). If it was doing this, the water would be scalding hot all the time.

Yet the OP says they have no hot water even with this switch on, unless the main boiler is also on?

OP.....is the main boiler gas fired?

A wire disappearing into a wall, that you cannot actually see is connected to the immersion heater element, could be going anywhere......even to another flat!

Do all the flats have the "boiler room" above each other?

I have no idea, but I guess I should ask my neighbour if they have one

I have been living in the flat for 3 years and i never switch off the main boiler before (nor the immersion one, as I said we didn't know there is one), until I receive that high bill two months ago, I start thinking that it might be the main boiler that cause me a lot (as i still didn't know about the immersion one), so switch it off when I am not using it. Then I found out that when it is off, my heating is not working, and no hot water.

Now I am told that there is immersion heater, I start wondering why there is no hot water then when the main one is off.

I am just so confused! Just like what I thought, even there is an immersion boiler, when the main boiler is on, the immersion one should not be working at the same time as it is just a spare one. Then how come it could cost me so high when it is not running 24 hours per day?

As I observed, it usually cause the meter run fast (on and off) at night and in the morning, less often in the afternoon. It shouldn't cost that much...75 units per day compare to 6 units when it is off is a HUGH different.

ILW

I would get hold of one of the little gizmos that tell you how much elec is being used at any particular time (B Gas give them away free). Try to keep an eye on it ofr a day and see when the surge seems to happen. This sould give you a clue what is going on.

silvercar

I

am just so confused! Just like what I thought, even there is an immersion boiler, when the main boiler is on, the immersion one should not be working at the same time as it is just a spare one. Then how come it could cost me so high when it is not running 24 hours per day?

If both are running the same time, they will both work at the same time and the water will heat quicker. If the temperature for the immersion is set higher than the temp for the boiler, the immersion will always be heating the water that bit hotter.