heatrae sadia - looking for advice on electric heating and hot water

  • 6 March 2021
  • 7 replies

Userlevel 1

Hi, can anyone help a 57yr old builder with a 55yr old eco friendly wife? I’m looking at the heatrae Sadia heater. I can plumb it and get my sparky to live it up so installation costs will be very low. We live in an old(small) house with poor insulation (plenty in loft but 9inch brick walls). heating is an oil fired Rayburn, something I converted years ago, just a plain wick burner but it heats the water for us two to shower daily.  Other heating is two oil filled rads and a log burner. So,, as we get older we need more/some comfort. Given that we only need 5 rads totalling around 30’000 btu’s, will a 9 or 11kw HS do the job? and at what cost? My Mrs is against using too much oil and nearest gas is 4miles away.  




7 replies

Userlevel 7
Badge +11

hi @benthebuilder 

you don’t say what device you are considering, the name heatrae Sadia heater could apply to any of their products, water heater, megaflo, electromax etc. and although you may get advice on here I would have thought a better place to ask would be on one of the plumbing forums?

As far as eco is concerned whatever electric you choose will be supplied by green electricity if you’re with a green supplier, but the detailed costings will depend on many factors. 30,000 btu is just under 9kWh, which I suppose would be sufficient for your heating needs. I can’t see an 11kW version of the electromax and the amptec says it’s for heating only, so all of this depends on what you have now.

The only comment I would make is that providing heating and hot water solely by electric will likely cost maybe up to 4 times (3.5 to 4 times?) what it costs using oil only. (depends on oil prices and how efficient your current system is)

Others may add their thoughts but you need the advice of a good heating engineer /plumber who understands your current configuration and the best way to convert it. You’ll also likely need some substantial work at the consumer unit end and wiring even at 9kW you’ll need 6mm cable and at 11kW you’ll need 10mm cable (all depends on length of run) and is your main fuse suitably rated?

Get some professional advice.

Sorry if I’ve misunderstood your query.

Userlevel 7
Badge +11


and THIS might be of interest

Electric heating is the most efficient, the easiest to install and in most homes does not require any additional power provision and the existing ring main will cope. Check first. Most of us have at least an 80 amp fuse on the incoming supply which can cope.

As @woz so rightly says though it ain’t cheap to run and it is dearer to install. For a 4 bedroom home installers will quote you around £10k. But you can buy the radiators needed for about £5k and install it yourself. You need a screwdriver, an electric drill and some of those plastic plugs you screw supports in with! Mind you you may get them with the radiators.

That’s the installation cost. You get that back over the years for its life expectancy is  double or more of that of a boiler. But the running costs! I found suppliers were reluctant to provide figures. Indeed, they ignored me when I asked. I worked out that running an electric system would cost me a little over £2k per annum to heat the house. As opposed to £460 per annum to run a gas boiler.

As for size of boiler, most homes can be heated with a boiler of 12kW. Indeed probably less. Domestic hot water will need more so the boiler must be adjustable such that you can reduce the central heating maximum without affecting the domestic hot water.  Most installers will not advise you of this and most install your 90%+ efficient boiler leaving it running at far less efficiency.

Take care getting quotes. As I have found installers promote the boiler they are used to working with, and possibly get more commission for, they will tell you you need a new boiler when you may not, they will tell you you need new radiators but you probably don’t in most cases. The better makes of boiler are Viessmann and Intergas.

Last  Friday I was advised of a family in a 5 bedroom house with three bathrooms that the house was not getting as warm as they wanted whose “expert” immediately said they needed a new combi boiler. A combi for them would be completely wrong. The house still struggled to get warm so he then advised they replaced the radiators! So far they have I am told spent over £9k.

Before deciding to step over the edge, do some research, have a very good read of this site and indeed all of it. There is valuable helpful information therein - https://www.theheatinghub.co.uk

I am not on commission or employed by them, and whilst I did not employ their services, I found what they advised, and some other sites, focussed my mind.

Userlevel 7
Badge +9

In an old house from 6 years ago i had a 9kw amptec flow boiler fitted. It more than coped with 7 rads. Found it cheaper than a very old oil burner it replaced. With the log burner it was always toasty in the house when we were home. 

Itt did not do the hot water but we were told it was capable if we wanted to add it later. 

@Mavis1 that size boiler would probably handle a dozen radiators.

Hey @benthebuilder 

Great to hear you’re interested in more sustainable alternatives for your home :blush:

Just to let you know, I’ve moved your post to our section all about renewables and sustainability - sounds like your wife may be really interested in some of the topics being discussed here! I’ve also edited the title of your post slightly to help others searching for similar posts :thumbsup:

Looks like you’ve received some really in-depth replies already, hope it’s helped you with your thinking? 

Userlevel 1

Thanks everyone, all very interesting and positive. Looks like we’re going down the Amptec road and also ditching the ‘stinky’ Rayburn.