Electric Central Heating i.e Thermaflow v Amtec

Holmlea

Would love some technical and anecdotal advice regarding running (particularly costs) a wet central heating system with an electric boiler. We have been extensively researching the most cost effective (to run) system, to heat our renovated, small 3 bed (semi) cottage.
Oil and mains gas not possible, nor any of the modern heating systems i.e heat/air pumps ,solar systems etc.
Today we have narrowed it down to using a Thermaflow (heat store type) boiler (9kw 330l) to run 7 radiators and supply all the hot water for use (showers etc). Using an economy 10 tariff most probably from Scottish Southern (their times very compatible) even better the Economy 18 from Eon but this may not be available (because of stock!!!)
We are still open to installing a flow system like the Amtec from Heatrae Sadia but this seems even more expensiveto run....as do night storage heaters (plus do not like their inflexibility).
We are not factoring in the cost of installing the system with our running cost calculations as we have weighed this up seperately and the cost (ha ha within reason!!!), is less important than finding a system that suits our needs and provides as economical running costs as possible.
Would love to hear from anyone who has experience of these systems, any real day to day running costs....and pros &cons.
I have spent the day speaking to manufacturers, suppliers and even the Energysaving Trust all who have very little real information the nearest costings we could get were those based on Scottish Powers Ec2000 Tariff which is not available to us.

Thank you for reading this.

If it helps to have some more information.... this system is to be used by 2 full time workers and we are considering fitting a log burner (when funds allow) which we hope to use whenever possible but thought this might not be practicle on a day to day basis when we get home from work etc and when we get up...if anyone has information on these we would be interested too.

Cardew

Welcome to the forum.

The first, and most important, point to make is that all electrical heating systems will give out EXACTLY the same amount of heat for the same running costs. So the heat a room to xC for yhours will use zkWh and cost the same.(using the same tariff)

Using E10 will give you far less choice of Energy supplier as most simply will not cater for E10 - E7 and single tariff are their staple tariffs. In any case E10 charges often make it less attractive than E7.

So you are really down to the controllability and flexibility of an electrical heating system.

Here we are in the realms of personal opinion, and I cannot think of anything less flexible, or indeed controllable than a 'wet' electrical radiator system; even with a 9kW boiler and a large heat store. If you don't(understandably) like night storage heaters because of their lack of flexibility, you have largely the same issues with a wet system plus a pump and radiators/pipes.

Personally, as you are out all day, I would go for simple panel type heaters that can be used with timers and even remote controls. Instant heat, exactly when you want the heat and if you shy away from these stupidly expensive 'systems' much cheaper to install. The savings on installation costs alone will offset higher running costs on a single tariff.

However as I said - a lot of this comes down to personal choice; so good luck whatever you decide.

Holmlea

Thanks so much Cardew for taking the time to reply we appreciate your comments.
The running costs do appear to be different between the thermaflow and an actual flow system boiler as the thermaflow mainly utilises off peak electricity, but we still have so many unanswered questions that we are reluctant to proceed on just the manufacturers details and claims.
In this stage of our renovation I think we would be foolish not to consider installing a central heating system as this rightly or wrongly it is something prospective buyers insist on and whilst we intend this to be our family home we do have to look to the future and cover all bases. Also as we would love to have a family one day, our heating needs will change so I think panel heaters would become very expensive to run.
I have just heard back from our surveyor who kindly consulted a heating engineer who is unimpressed by electric boilers but I'm not sure if he had experience of the thermaflow! He thought gas (bottles)were our best option......so we have gone full circle and as one friend suggested.....Thick jumpers are our best option !!!
Thanks again cardew and all who took time to read it....and thanks to moneysavingexpert and the forum this site is invaluable

peat

I was running a wet electric heating system using a 12 kw Amptec heater linked to a 250 litre thermal store running on Economy 10. The system worked reasonably well but the store was not big enough to heat the rads for an adequate length of time outwith the cheap rate periods which were the only periods that I heated the water. Consumption for a 3 bed terraced house was around 16,000kwh per annum of which 80-90% was cheap rate. Heat in the house was adequate in my view but my OH would say differently. I have since added an ASHP to the system - the jury is still out on the economics of my addition - time will tell.

grahamc2003

Holmlea wrote: »

Would love some technical and anecdotal advice regarding running (particularly costs) a wet central heating system with an electric boiler. We have been extensively researching the most cost effective (to run) system, to heat our renovated, small 3 bed (semi) cottage.
Oil and mains gas not possible, nor any of the modern heating systems i.e heat/air pumps ,solar systems etc.
Today we have narrowed it down to using a Thermaflow (heat store type) boiler (9kw 330l) to run 7 radiators and supply all the hot water for use (showers etc). Using an economy 10 tariff most probably from Scottish Southern (their times very compatible) even better the Economy 18 from Eon but this may not be available (because of stock!!!)
We are still open to installing a flow system like the Amtec from Heatrae Sadia but this seems even more expensiveto run....as do night storage heaters (plus do not like their inflexibility).
We are not factoring in the cost of installing the system with our running cost calculations as we have weighed this up seperately and the cost (ha ha within reason!!!), is less important than finding a system that suits our needs and provides as economical running costs as possible.
Would love to hear from anyone who has experience of these systems, any real day to day running costs....and pros &cons.
I have spent the day speaking to manufacturers, suppliers and even the Energysaving Trust all who have very little real information the nearest costings we could get were those based on Scottish Powers Ec2000 Tariff which is not available to us.

Thank you for reading this.

If it helps to have some more information.... this system is to be used by 2 full time workers and we are considering fitting a log burner (when funds allow) which we hope to use whenever possible but thought this might not be practicle on a day to day basis when we get home from work etc and when we get up...if anyone has information on these we would be interested too.

I can offer experience of a large house heated by modern(ish) storage heaters, with a recent(ish) addition of a wood burning stove, if that's any help.

When you have Hobson's choice (i.e. only electricity or bottled gas, and no possibility of heat pumps), then modern storage heaters, correctly sized on e7, are a decent, but not perfect, solution. If your house is small, it would be easy to oversize the storgae heaters and have a hot house should you wish. We have our house cool, (and in this weather, don't have the bedroom heaters on at all). all the time, except for the living room with the wood burner which we can have as hot as we want, but try to keep around 20).

The wood burner is great - but don't underestimate the hassle! If you are at work all day, you proably wouldn't relish the thought of lighting a woodburner (at least after the honeymoon period!). If you buy in seasoned wood, It will probably cost more than e7 electricity to run.

I think for e10 tariffs, you have to use pretty much all electricity during the cheaper periods compared to e7, and e10 seems to be designed for systemns which don't have enough heat storage from just nightime heating. You can store a lot of heat in a few storage heaters, but not a great deal in water, hence the large tanks and daytime topup tariffs. I'm amazed at the high 'cheap rate' e10 charges.

I've no experience of wet electrical systems, but I think you're right to be extremely careful to weigh up the (real) pros and cons before splashing out (ho ho) on one, and look on with lots of scepticism any manufacturer claims (as obviously you are rightly doing by dismissing finned/magic ingredient filled very expensive panel heaters, when cheaper ones do the same job).

gc_bus

For information:

Two weeks ago we had an Elnur CMX15 electric combi boiler fitted along with 6 radiators controlled via a Myson MPRT RF "smart" chronostat. The boiler has been restricted to use a maximum of 6KW from a new 32amp supply. The CMX15 has an on-board 50 litre hot water store. We're running the boiler on a standard tariff from nPower at 10.5p/Kwh (inc. VAT). The boiler takes 14 minutes to re-heat the water store from cold.

Our house is a 2/3 bed modern mid-terrace and is very well insulated.

Despite it having been a very very cold couple of weeks I've worked out that our total electricity usage in the last week was £33.05 (including VAT & standing charge of 25p per day). I'm very pleased with this.

We also have a 1.7Kwp solar PV installed but this only generated 4Kwh in the past seven days having spent much of its time covered with snow.

The chronostat is set to come on 05:00 - 07:00 at 21c and 15:00 - 22:00 at 22c dropping back to 14c all other times. All but the bypass radiator in the living room (where the chronostat is fitted) have TRV's.

We do have a gas supply available but do not use it and pay no standanding charge. Also the electric boiler needs minimal servicing and no inspections per se.

Another factor in our choice to go electric was from a safety perspective (no fume ingress possibility) and also no requirement to bash through the kitchen wall to fit a flue.

Very pleased with the new boiler and the hot water from the store gets to the taps in 3-4 seconds as opposed to a gas combi which can take 30-45 seconds (if no on-board store). Furthermore a gas combi often pumps excess hot water around the radiators when the hot tap is turned off to avoid overheat which can appreciably heat up radiators (as previously experienced) in the warmer months which is not too desirable. The electric combi boiler does not do this.

So, we're pleased with our installation and running costs. :j

Please feel free to ask any questions.

gc_bus

p.s. the new electric boiler/CH system replaced some previously installed "electric radiators" that we pretty useless to be honest - cheapish to run but ineffective as they seem to modulate down really low to save energy but then of course gave out little heat.

fishybusiness

Hi,

We are in the process of moving away from using electricity for heating, and if I had to choose, I would go for storage heaters or panels, rather than a full electric heating system.

Also as we would love to have a family one day, our heating needs will change so I think panel heaters would become very expensive to run.

I can't see there being much difference in cost between heat generated in a central store or by individual panel heaters, same electricity, same room sizes, same times of day.

gterr

We have installed an Amptek (?9kW) boiler in our holiday cottage. This runs radiators and heats hot water, in a conventional arrangement with a timer regulating heating and hot water separately, TRVs on the radiators and a tank thermostat on the hot water cylinder.

There was an existing very old open fire with back-boiler running rads, so we didn't have to start from scratch, though we had to replace one or two very old radiators.

We ran this on Economy 10 for a year, but looked carefully at useage (total kWh) and worked out we'd be better off on a standard tariff, especially since we'd then be able to shop around for the best deal (much more choice with a standard meter than with an Economy 10 meter).

We have been pleasantly surprised at how reasonable the costs are: not as low as you'd get with modern technology such as ASHPs, perhaps, more like the average heating bill for a 2-bedroom detached bungalow in the Highlands. Also, we don't have annual service charges for the equipment. It takes up very little space and does not need an outside wall (no flue) or an oil tank.

Whatever you decide I would definitely steer clear of storage heaters: expensive and difficult to control to fit most peoples' lifestyles.

gc_bus

gterr wrote: »

We have installed an Amptek (?9kW) boiler in our holiday cottage. This runs radiators and heats hot water, in a conventional arrangement with a timer regulating heating and hot water separately, TRVs on the radiators and a tank thermostat on the hot water cylinder.

There was an existing very old open fire with back-boiler running rads, so we didn't have to start from scratch, though we had to replace one or two very old radiators.

We ran this on Economy 10 for a year, but looked carefully at useage (total kWh) and worked out we'd be better off on a standard tariff, especially since we'd then be able to shop around for the best deal (much more choice with a standard meter than with an Economy 10 meter).

We have been pleasantly surprised at how reasonable the costs are: not as low as you'd get with modern technology such as ASHPs, perhaps, more like the average heating bill for a 2-bedroom detached bungalow in the Highlands. Also, we don't have annual service charges for the equipment. It takes up very little space and does not need an outside wall (no flue) or an oil tank.

Whatever you decide I would definitely steer clear of storage heaters: expensive and difficult to control to fit most peoples' lifestyles.

Yes, I am pleasantly surprised how little our electric boiler C.H is costing us especially considering the recent cold spell.

I too looked at E10 but dismissed it when looking at the cheap rate of 8.5p/Kwh and the peak rate at 16.5p/Kwh compared with our 10.5p/Kwh on the standard rate. The chronostat currently shows 19c with no heating being on since 07:00 - just shows what really good insulation can achieve. :j

malc_b

My mother has E7 storage rads. These have a central miser control which senses the outside temperature overnight and adjusts the charge time. So cold night you get a full 7 hrs, warm night you get less. The miser has a knob on the front so can can adjust it for how you like it (cool house or warm house).

E7 storage probably works best for people at home all the time, but having said that the difference between 24hr and not 24hr in any house is not that much (15-5%) because of the heat storage in the house structure.

I don't know if they have improved storage radiators since my mother had them fitted but if I was going down that route I'd want remote control of the rad flap (which you open to let more heat out).

Ben84

gc_bus wrote: »

p.s. the new electric boiler/CH system replaced some previously installed "electric radiators" that we pretty useless to be honest - cheapish to run but ineffective as they seem to modulate down really low to save energy but then of course gave out little heat.

That's why they were cheap to run, they weren't emitting enough heat. There's no difference in the efficiency of electric heaters, for every kWh of electricity going in a kWh of heat comes out.

Anyway, not all electric heaters are good. There's some really flimsy panel type heaters which are pretty much a thin metal case full of wires similar to a toaster. They emit almost no radiant heat and tend to make your house smell like burning dust all winter. If I had to buy an electric heater, I'd get an oil filled heater, they emit heat in a very similar way to a hot water radiator and the element is properly hidden inside the case, making it safer, plus dust and dirt can't get inside.