I'm looking for some advice and opinions on the choices of central heating options available to me.
I currently have a 3-bed semi which has a coal fired central heating system and hot water supply.
We do not have access to mains gas and an lpg tank has been ruled out due to the layout of the boundaries of the property and close proximity to an electric pylon.
I have been researching oil and electric combi boilers for central heating and hot water.
I know the oil tank has less restrictions on where it can be sited and there are internal and external oil combi boilers available.

I'm hoping someone would be able to give advice on the electric combi boilers available.
I don't know of anyone who uses them to get feedback regarding running costs etc.

I've been looking at the Thermaflow Electric Combi boiler (I cant post the link as new user and to stop spammers -
This appears to me to be a possibility and running the electric boiler on Scottish Power's Economy 2000 tariff will give have price electricity costs for 18 hours per day.

I would be grateful for other people's thought, opinions and especially experience of using the Thermaflow boiler.

Examples of Tariffs Available for electric wet heating systems

This example is based on the requirements of a typical family home where hot water is required to heat seven radiators and supply hot water to taps. During the winter, which we will assume covers half the year (180 days), heating and hot water is required for 8 hours each day. During the summer (180 days) water heating is only required for 1 hour each day.

The heating is on as follows;
Winter: 7-11am & 5-9pm
Summer: 5-6pm
THERMAflow Boiler
The Thermaflow storage boiler range are able to operate on the Scottish Power Economy 2000 tariff which will give 18 hours of constant electricity supply at half price.
This example is based on a 210 litre Thermaflow with an output of 9kW
The shut down periods are:
00:00 - 02:00
08:00 - 10:00
16:30 - 18:30
If the boiler is used at maximum, (heating and hot water), for 180 days a year - consuming 9kW/hr, and used for hot water over 180 days - consuming 3kW/hr, the total annual consumption is 13500kW/hrs.
This is Off-Peak electricity and the rate at 01/01/2007 is 5.5 pence per kW/hr.
(cost = electricity used x rate)Peak Rate Electricity used 0kW/hrsOff-Peak Electricity used 13500kW/hrs.Cost of electricity used£663

Economy 10 tariff for other Electric Combi Boilers
Flow type boiler using economy 10 tariff
'Flow' or 'Direct Acting' boilers can only operate on meters that provide 10 hours of Off-Peak electricity per day provided by Scottish Hydro Electric.
This example is based on a 9kW boiler and a 3kW hot water element.
Off-Peak times are:
04:30 - 07:30
13:30 - 16:30
20:30 - 00:30
If the boiler is used at maximum, (heating and hot water), for 180 days a year - consuming 9kW/hr, and used for hot water over 180 days - consuming 3kW/hr, the total annual consumption is 13500kW/hrs.
This will have to be based on 7 hours of On-Peak and 1 hour Off-Peak per day in winter and 1 hour at peak rate per day in summer.The On-Peak rate at 01/01/2007 is 9.1 pence per kW/hr.

(cost = electricity used x rate)Peak Rate Electricity used 11880kW/hrsOff-Peak Electricity used 1620kW/hrsCost of electricity used £1170

As demonstrated above the THERMAflow boiler offers a saving on cost of electricity used of £507 over the first year compared to using the equivalent direct acting boiler based on electricity tariffs available in Scotland May 2007.
Contact your electricity supply company for accurate and up to date tariffs and their costs.

Any thoughts?



  • Did you go with a Thermaflow? I have a similar problem and i cant find any reviews on this boiler. I dont want to take advice only from the supplier, I would rather find someone that has it installed.
    Hope you can help
  • Owain_MoneysaverOwain_Moneysaver Forumite
    11.3K Posts
    Part of the Furniture 10,000 Posts Name Dropper
    These aren't combi boilers in the conventional sense of the word i.e. a boiler that heats the water instantaneously.

    They use a wet central heating system (radiator and pipes) with a 9kW electric boiler. This is significantly smaller than most gas boilers, so will take a lot longer to get the house up to temp from cold. You have the disadvantages of a wet system (leaks etc) with the high costs of electricity.

    The hot water is heated in both systems in a large insulated hot water cylinder with a 3kW immersion heater, so you have to wait for the water to heat up (usually overnight).

    You may note that the total consumption for both units is "the total annual consumption is 13500kW/hrs" so the only difference is the tariff. You would have to work out whether the off peak rate of the Economy 2000 tariff is sufficiently less than the peak/off-peak mix of storage heaters or panel heaters.
    A kind word lasts a minute, a skelped erse is sair for a day.
  • Stu1Stu1 Forumite
    7 Posts
    Has anyone actually got this Thermaflow combi boiler?

    My mother needs a new system and we're looking at it for her. But I don't want to take the leap until I've read more from people who've got it.
  • I have a Thermaflow heating system, (high efficiency slimline electric combi boiler) i find its easy to use all i do is have it on timer for the winter, but just click on thermostat if and when i need it in the summer. I am with scottish powers Economy 2000 tariff. it has 3 shut off periods: 8am-10am, 4.30pm-6.30pm, 12am-2am. it get wired directly to the low rate supply from the meter, and will re-heat automatically when required. you do-not need to touch the boiler, the boiler holds a 24 hour supply. it can seem expensive to run, my-self topping £40 per week in the winter but that is covering heating being on most of the day, cooker, lights, television, kids xbox's and tvs being on to, washing machine, tumble dryer and hot water, we can get 4 baths run in a night from the boiler. within a 3 bedroomed house, full electric, no gas. when you consider what gets run off it its ok. and what you would pay combining electric and gas or even coal etc, works out about the same, we had coal previously, £15 a bag 3 bags a week in winter, thats £45 before electric. :rotfl:
  • i have had the boiler in since monday and have already used £35 credit on my electric meter i cant do my washing or anything as i cant afford to put anymore money in yet i am also on scottish power economy 2000 but can someone tell me what temperature and what time to set it at as scottish power said theres nothing they can do:(:(:(:( i live in a 3 bedroom house please help me x
  • can you please tell me what time you have your boiler set to and at what temp you have it as i have no money left until next week and my heating has took £35 since monday thats only 2 days ago what am i doing wrong im also on same tariff as you scottish power economy 2000 help would be much appreciated im in a 3 bedroom house to scared to use washing machine or have bath as cant afford anymore money thanks
  • Scottish_PowerScottish_Power Organisation Representatives - Private Messages may not be monitored
    1.3K Posts
    Hi kazzam2012,

    You may be able to find how best to set your heating system by checking on the manufacturers website. If not you can call our energy efficency advice line on 0800 33 22 33 and they should be able to help.

    Kind regards

    Graeme @ ScottishPower
    Official Company Representative
    I am the official company representative of Scottish Power. MSE has given permission for me to post in response to queries about the company, so that I can help solve issues. You can see my name on the companies with permission to post list. I am not allowed to tout for business at all. If you believe I am please report it to [email protected] This does NOT imply any form of approval of my company or its products by MSE"
  • edited 2 March 2012 at 11:43AM
    jonkayakerjonkayaker Forumite
    1 Post
    edited 2 March 2012 at 11:43AM

    I came across this page today while looking for info on second-hand and/or scrap values for the ThermaFlow bolier.

    I moved into a new property in December. The property has (had) a Thermaflow bolier. It's one of the larger models. We are on one of the dual tariffs. When we first moved in we werent really paying attention to the usage - we took initial readings for moving in and that was that.

    After a month we had a look at our usage. Just over £500. Now we weren't being particularly careful with usage so that will play a part in the total. However when we did use the system it never really produced the heat in the radiators and/or running water that we would expect. Again there will be many factors regarding how well commissioned the system is, insulation in the house etc. But what is important is that even with no central heating running and/or water usage - the boiler keeps heating it's tank of hot water and this burns money. A lot of money.

    Our boiler is being replaced this morning - with £500 running costs we will recoup the cost of a new boiler in a realitively short period of time.

    I certainly would not recommend one of these boilers if you have a large and old house. Maybe in a modern well insulated building the numbers may stack up a little better.


  • I bought a Thermaflow unvented boiler, a TH12-250U. I bought it on the recommedation of the plumber who fitted it as he told me it would meet my requirements. i.e. 8 double radiators, 4 shower cubicles, a bath, 4 hot towel rails, 6 wash sinks.

    What I have found, is that when the central heating is on in the mornings and you go into a shower, the water runs cold after a few minutes, I've also noticed that the radiators although they get warm, I can put my hand on them without burning, so not so hot. I phoned the manufacturer to try to remedy it, but it seems that it is not sufficient to run this installation I the max energy it has to heat water is 12kwatt and if other electrical things are running at the same time, like a dishwasher or washing machine, kettle etc, then the power is decreased to the boiler and it doesn't work as it should. I am going to run a bed and breakfast, so if this problem can't be fixed, I will have to rip it out and sell it on ebay and install a boiler that can do the job.

    These boilers may probably be ok in houses with one shower, but don't buy one if you are going to open a B&B or guest house, or have a large family who jump into showers one after another as the water will just run cold. It was money down the drain for me, an expensive learning curve £2,700 plus VAT

    Moral of this story, is make sure you size your house to find out how much energy is required to heat the rooms and the hotwater, don't take any person's word it will do the job, not even a plumber!!
  • edited 24 July 2013 at 8:10PM
    marshdaisymarshdaisy Forumite
    6 Posts
    edited 24 July 2013 at 8:10PM
    Had mark I boiler fitted last May and very pleased with it. You have to make full use of the cheap rate periods to charge it up - and econ 10 only available in England from Eon or EDF (existing customers onky). We have since linked a woodburner with backboiler to it and are in the process of linking in a solar water panel.
    You do need a lot of space for tha actual boiler though as they are pretty huge!
    The earlier models had a problem with boiler thermostats - installer should replace FOC. So if you arent getting enough hot water etc that may well be problem. We had the 'cold second shower' problem but new stats sorted that out and now all running verybwell.

    This discussion has been closed.
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