Replacing old electric heating system

michty6 wrote: »

I just bought a new place for my Mum (fairly large 2 bedroom flat). It has an electric immersion hot water heater as well as very, very old electric storage heaters (radiators) from like the 1970s throughout the apartment. It is absolutely swallowing money, whilst not offering much in return (hot water doesn't last long, radiators switched off to save money but still doesn't seem to do much).

I am wondering what the best option is to sort this is (assuming I stay with electric heating). I (sort of) have had 2 opinions and am wondering what people on here think.

One was to put in an electric boiler and new radiators throughout the apartment. The other (from the Home Report) was simply to put in fan assisted storage heaters (doesn't say anything about the electric immersion heater).

Any ideas? I would consider gas, but it seems like the installation costs would be huge...

- green bar TRHS called "Search this Forum"
- put E7 in "Search this Forum"
- hit return

Read a few of the posts then come back and ask your questions, you also need to tell the forum what tariff you are on, you shoild be on an E7 or E10 tariff ? Both your storage radiators and water should heat up throughout the night and be outside of your control. Is that what happens ?

Other questions will arise for example is the flat in a block with a gas service ?, many E7 properties were built with E7 simply because there was no gas supply service.

If the storage heaters are very old, undersized and in a property with poor insulation and single glazing, it may be time to upgrade the storage radiators and and direct hot water cylinder to a more efficient modern insulated spec, which would cost very considerably less than the cost of a new GCH system and the change in metering / cabling / etc.

NOTE : What you describe as an immersion heater [you control it] would have a single heater element at the bottom of the cylinder. If it was a proper Night Store water cylinder [you do not control it] it would have two two heating elements, one at the top the other at the bottom - which is it. See #32

michty6 wrote: »

- It seems to me that GCH would cost ~3k to install, assuming we can connect to the mains but I will definitely look into it. I want to consider what my other options are as well though, especially since I've just bought the place so cash flow is very tight just now!
- Yes I read about the E7 and E10 tariffs, have not confirmed with Scottish Hydro that that's what we're on but will do so tomorrow (they're closed now).
- My understanding is that our storage heaters are supposed to heat up during the night but I don't know if this is what is happening in practice. One of the issues is that the controls on the radiators are terrible and nobody has been able to work out how to work them (I am not in the UK just now so haven't seen this first hand). Furthermore, some of the radiators are apparently different to the other ones. An electrician, who was looking into doing some other work for us, said they were from the 1970s and are probably the worst radiators possible - hence why I were considering potentially just replacing these.
- The property is a 1st floor flat but with a ground hallway entrance (stairs as soon as you enter). So lack of gas supply service could be an issue. As noted, this is something I need to check.
- The insulation in the flat isn't great, according to the home report. But it is at least double glazed.
- I have no idea about the immersion heater, I will have to get someone to check.

Based on both your responses my thoughts are (if GCH is not an option) to get the immersion heater checked out by and see if it needs upgraded/flushed or the cylinder replaced, and to look into getting more modern fan assisted storage heaters with better controls... My question would be how I go about doing this (the immersion heater in particular)?

What exactly is wrong with the immersion heater? It's usually rated at 3kw. If it fails then it uses nothing. If the thermostat fails and it stays on all the time then the water will be far too hot and eventually the overheat protection thermostat will cut out and the it will no longer work. It won't use any more energy if it's old as the energy it does use has to go somewhere and that is into the hot water in the cylinder. Immersion heaters have and always will be 100% efficient at point of use. The inefficiency is in the cylinder...is it insulated and/or lagged? The heat lost from the cylinder though will heat up the property so not all is lost especially in winter.

If you are going to install / update the storage heating, then I would also budget to throw as much money as possible into improving the insulation. Storage heaters (new or old) are notoriously poor in draughty or poorly insulated properties.

In fact ANY heating would benefit in a review and potential improving of the house insulation.

Unfortunately, Electricity will also be the target of choice for continued price increases and whilst people are getting generous hand outs for wind turbines and solar panels, and Europe are pushing for the closure of many of our 'dirty' coal and gas fired power stations, Electricity only customers generally end up footing the lions share of the big green payout.

In the last few years alone, i've personally seen the price of Off Peak Electricity rocket from around 4.3p to between 6 and 7p a unit, and it won't be long before E7 off peak equals the 10p or 11p which many are getting 24/7 on standard non E7 tariff's. This compares badly to the increases seen on Gas tariff's which, even today still only hover around 3p - 4p per kw/h

You also have to bear in mind that E7 customers generally pay more for their peak rate Electricity, and so the 'generous' reduction given against 7 hours of off peak Electricity isn't that brilliant when you overpay for daytime power, as the Electricity company claw back some of their discount. Certainly whilst off peak rates continue to catch up on standard Daytime Electricity, the margin is narrowing.

On some tariffs E7 is actually only 3p cheaper at 7p per kw/h than the 10p per kw/h which some here profess to pay for standard tier 2 non E7 electricity!.

One was to put in an electric boiler and new radiators throughout the apartment

Which will swallow even more money. These are notoriously expensive, even more so than E7 storage heaters. Generally they run on E10 tariff's which are slightly more expensive than standard E7 electricity at around 8p kw/h.

This means that a 10kw boiler will consume around 80p an hour in Electricity at 8p per unit, a standard 14kw with a heatstore one will use a whopping £1.12 an hour, even at heating off peak rates.

Unfortunately, the 150 litre water store which can be provided for these boilers doesn't last very long, when constantly circulating water around open pipework, feeding several radiators especially if your Mother is at home all day. This generally means that the boiler has to also do some heating during the peak periods during the day in order to top up the heat store, and this can work out extremely expensive.

It sounds like the house is fairly old, so depending on the wiring and service head, you may have to pay the local DNO to 'upgrade' the service head feeding the property if you choose an Electric Boiler. This is generally needed as the 14kw load from the boiler can often max out an older 60A service fuse singlehandidly, even before a cooker, shower and other general household consumption etc is taken into account. So you should also budget the possibility of that, and also the possibility of a new consumer unit or rewire depending on the age / state of the existing installation

Unfortunately, since the demand of an Electric Boiler is fairly constant it generally isn't included in most DNO's rule of diversity.

macman wrote: »

An electric boiler will cost approx 350% more to run than an E7 storage heater system. A crazy idea.
Either bite the bullet and go for gas CH and DHW, or sort out the night storage system and remain on E7. More expensive to run than gas CH, but much less than Standard rate all electric heating!
E7 is highly suited to a property that is occupied for most of the day.

Where do you get your figure of 350% more from?

Yes it'll cost more with no tariff change but I would assume someone would change to a standard tariff if they are no longer using E7 effectively.

So using my area East Midlands and my supplier and tariff Npower E7 the night rate is 5.775p/kWh and when changing only the tariff to a standard tariff with the same supplier the standard rate is 15.53p/kWh. A 169% increase. However, by comparing other tariffs with other suppliers I could get standard electricity for 11.55p/kWh with Ovo Energy which is 100% more expensive than E7.

I cannot find any supplier that is 350% more expensive than E7. The most expensive day rate is Npower's tier 2 rate at 18.501p/kWh which is still only 220% more expensive than the E7 rate and that's the worst rate and it's nowhere near 350% more expensive.

macman wrote: »

Point taken, I was working on a rough and ready 4p/14p ratio.
But even if the difference is 'only' 220% more, is that still really a sensible way forward for the OP?
All electric heating on standard tariff is the single most expensive method of heating.

That's the worst difference in rate. The best rate being 100% more. The average of the two being 160% more expensive.

It's an option. It may be a sensible option... Storage heating is good but gives out heat at the wrong time of day. Useful and economic for people who are at home all day and can take advantage of it but for the general population who leave their small flat all day and go to work or just out it's actually quite inefficient (not the efficiency of the appliance just the efficiency of using the heat) and it's cheaper just to use a convector heater for a few hours each evening when they can sit in front of the heater and actually feel the benefit of it.

Standard rate electric heating is used by many people in this country and the bills aren't as huge as you seem to imply as they are using spot heating....heating one or two rooms at a time as opposed to gas central heating or storage heating which heats the entire house including unoccupied rooms such as the bathroom and the bedroom when only heat is required in the living room and vice versa when the occupant goes to bed and the heating is still unnecessarily heating the living room.

Personally I wouldn't go for the wet central heating as I feel that is a overkill when simple and cheap convector heaters will suffice and as the gas central heating installation costs are too high for the OP to bear then my option is either manage the existing storage heating better or a tariff change and using standard convector heaters.

If electric heating on standard rates are so bad then why are millions of electric heaters sold each year and why do so many commercial premises I have been to use standard rate electric heating. The pub uses electric heating in the smoking area....gas bottles would be cheaper to run. The rail station uses electric heating in the waiting room constantly on 24 hours a day when a gas fire would be cheaper to run. Even going through the entrance of the supermarket there is an electric fan heater above the entrance heating customers as they enter surely a warm air gas furnace would be cheaper to run.