Anyone got an electric (wet) boiler?

[briggster]

Does anyone in here have an electric (wet) boiler (i.e. plumbed into a standard Y plan system)?

If so, can I ask roughly what size property you have and what your 'leccy bills are? (If that's not too personal a question )

The reason I ask is that we are in the middle of an extension and need a new boiler and up 'till yesterday it was pretty cut and dry that we were going to install a new condensing oil boiler. (There's no mains gas to property)

But our plumber's suggested fitting a 12wk electric boiler instead and claims that he's done at least three of them in our town (Frome) and that each customer has claimed a reduction in fuel costs!?! (one customer was oil, another one lpg/propane I believe).

Now I know if you run the numbers purely on BTUs/Kw for kerosene and electric and figure in 92% efficiency of an oil boiler that electric works out around twice as expensive as oil. But I'm wondering if the combination of combusting oil/heat exchange/exhaust heat/boiler cycling (starting and stopping the burner to mainting the water at 80deg) can possibly lead to a complete system (boiler) that can put anywhere near 92% of the energy of the kerosene in to the circulating water?

On the other hand the 'leccy boiler is direct in the circulating water and except for losses due to do resistance it is as near to 100% efficient as possible. (second law of thermo and all that)

Can you see my dilemma? Please chirp in with any definitive answers or especially if you have a wet electric boiler yourself!

 

[briggster]

Has nobody got any data on this?

A useful figure would be an average oil consumption for a 15-19 boiler?

I've since found the following figures on the 'net:

1) figure in 10% loss in efficiency for the duty cycle of a boiler
2) 5% loss for transport through the pipes (which would be the same for elec or oil)

cheers

 

[gas4you]

I've only ever fitted one, a 6Kw Amptec. Was costing the customer approx £450-£500/quarter 3 years ago

 

[simond]

This is a simple one;

Cost per KwH of oil heating typically 5p-6p per Kwh

Cost per Kwh of electricity typically 11p-12p per Kwh

Cost of LPG per kwh typically 6p


The aforementioned assume a condensing boiler and electricity at a normal day tariff. NB: To be pedantic you can run elecs at 4p per unit when on an Economy 7 tariff but this is in the middle of the night....when you don't have your heating on.

So to summarize, what a load of nonsense you have been told, find another installer.

Before I go, look at air source heat pumps. These are available from Nibe, Mitsubishi Ecodan and Worcester Bosch amongst others (there is an easy to understand page and manufacturer links on my website, see profile). With an air source heat pump running off electricity, you could be running your system at around 3p per Kwh........

 

[diverdee]

they do seem to be much more to run than gas.they are used mainly where gas supply is not available or commercial where 3 phase is available

 

[simond]

3 phase doesn't make a heater more eco to run.

 

[diverdee]

no i agree but the price of three phase commercial is much cheaper hence often used in offices ect at commercial buildings