help with which heating system, electric radiators vs water filled radiators

elpato

Grateful for some help. My son and partner need to upgrade their oil powered central heating (combi boiler). They are off-grid. The house is mid-terrace and on 3 floors but nearly all the time only the ground floor is occupied. They keep erratic hours so storage heaters probably wouldn't work. All the water-filled radiators (12) are very old and need replacing.  Also an extension add-on will need another 3 radiators.  They spend nearly all their time in 2 or 3 rooms so don't need to heat the whole house. The insulation will be upgraded and new windows fitted. The payback time for solar makes it difficult to consider.  Not really interested in heat-pumps ecause of installion and running costs.  Don't really want underfloor heating either as it takes a long time to heat up.  So the question seems to be to add a new electric boiler (which I understand would need to be the most powerful available to meet the energy demands on the rare occasions that the property is fully occupied) and upgrade all the radiators or to, e.g., have electric radiators (but which ones?) in the rooms they use most with the other radiators upgraded....unless anyone has any better suggestions...please!!  Also, would batteries that can download cheap nighttime electricity be a good idea?

elpato

Forgot to mention, would like the system to be on 2 controls (1 for ground floor and 1 for the others) so something like hive.

Gerry1

An electric boiler will bankrupt them, and electric radiators on day rate electricity will also be ludicrously expensive.  Just look at the kWh prices !

BUFF

I would just upgrade/replace the existing oil-fired system but future-proofing by making sure that the new pipework/radiator sizes were compatible for future use with a heat pump & lower flow/return temperatures. 

molerat

Upgrade the oil boiler.  Electric wet boilers are about the most expensive form of heating out there.  Local council here are ripping them all out and installing gas and the ones they are keeping the tenants are getting a heating subsidy.

matelodave

Don't even think about an electric boiler to run radiators, they were a cheap and nasty way to install a central heating system but the cost of leccy just makes them ludicrously expensive to run.

Oil is far far cheaper than leccy, especially if you've got the infrastructure already there. Oil would have to be over £3 a litre to cost the same to run as an electric boiler.

As said above, if you've go to replace radiators then it would be a good idea to ensure that they are large enough to cope with low flow temperatures in the even that heatpumps become a bit cheaper to install and run in the future.

BTW I'm not against heatpumps, I've got one and I'm very happy with it but they aren't any cheaper to run than oil or mains gas at the moment and are very expensive to install

BUFF

matelodave said:

As said above, if you've go to replace radiators then it would be a good idea to ensure that they are large enough to cope with low flow temperatures in the even that heatpumps become a bit cheaper to install and run in the future.

the incoming Part L in June for England mandates low (<55C) flow temp. for new installs (assuming that a complete replacement of boiler, rads & hopefully controls too = new install rather than a replacement). Even lower flow temp. would be better though.

canaldumidi

Stick to oil.

Thermostats on all the radiators and separate control zones, so you only heat the areas you want to heat.

Forget any idea of using electricity.......

Reed_Richards

elpato said:

Not really interested in heat-pumps ecause of installion and running costs. 

The running cost of a heat pump, properly installed, would be about one third of the running cost of an electric boiler with wet radiators or electric radiators and an immersion heater.  You would need to replace all the radiators but you plan to do that anyway.  You can get a £5k grant to set against the cost of the heat pump so it might not be much more expensive to install than a new oil boiler, given that you will replace all your radiators either way.