Electric Combi Boilers

[Chris Sheppard]

Currently hunting round for soething to replace the knackred oil combi we've got and have been considering an electric one.

 

We're lucky enough to get our electricity really cheap and what we'd spend extra on electricity shouldn't be any more than what we pay a year on oil I'd think.

 

But, am struggling to find an electric combi boiler that just does the hot water on demand and can be used independantly of the central heating so we can switch the heating off for the rest of the year.

 

We don't have a hot water cylinder fitted anywhere so a self contained combi seems to be the simlest solution.

 

Been looking at Heatrae Sadia Electromax Combined Electric Boiler but it has a 180l tank inside it and is huge - surely they can't all be like this as our current oil one is half the size and that includes all the burner and everthing too!

 

It's not like we have a huge demand for hot water and the heating never really comes on a lot either, but the fire isn't up to warming the whole house and it's going to be a while til I can swap it out for a stove.

 

Anyone any suggestions or experiences? It's all baffling me a bit now.

[openspaceman]

 

It's not like we have a huge demand for hot water and the heating never really comes on a lot either, but the fire isn't up to warming the whole house and it's going to be a while til I can swap it out for a stove.

 

 

A 10kW on demand electric heater, as used in showers, can deliver 50C heat at a reasonable rate for DHW. with a delta T of 40 every 10 litres of hot water should use around 1.7 kWh, this is an acceptable but not invigorating shower. ( My heart sinks when I arrive at a B&B and see one of those instant showers that feel like standing under an incontinent rat )

 

If you do use electricity for space heating and depending on how low the outside temperature gets then a split air conditioning unit can be worthwhile. If the inside target temperature is about 20 and outside is 5-10 the COP is around 3. I'd avoid using your current wet system radiators as they will not get enough power out of the lower flow temperatures.