Electric boiler for hot water only, and removing all radiators

[Philip Mcnutt]

Hi,

The house I am buying is a 2 bed mid terrace, and is not on the gas network. The gas combi-boiler is run off LPG cylinders, and provides both hot water and heating. This is a direct system, and there is no storage tank.

I am planning to go solar at some point in the future, and I want to replace the gas boiler with an electric one, and replace all the radiators with electric underfloor heating. I would like to locate the boiler and an indirect unvented cylinder in the loft, and once I get solar, use that to heat up the water during the day for use in the evening, or heat water during low electricity cost period.

I have a question about boiler power and selection. If I am planning to use an electric boiler in conjunction with a cylinder, does the boiler power not matter all that much? I don't want to over spec the boiler, and I figure that since it won't be feeding radiators, the power requirements will be lower.

I will be living by myself, so I am not expecting to use much hot water, but I want to make sure it's fit for purpose if a family move in after me.

Does this sound like a silly idea? Any advice would be appreciated.

 

[Mottie]

If you’re not using a boiler for heating, why not use an immersion heater?

 

[ericmark]

I would look at the Willis External Immersion Heater an Irish invention never seen them used but the idea is it heats tank from top down so within minutes you have hot water, but in fullness of time it will heat the whole cylinder.

As to under floor heating it does depend on the house, it is very slow to react, so depends on how much the sun warms up rooms. My first and second house no problem, but mothers house and this house the sun can heat up living rooms quickly when it comes out. So I need fast acting TRV heads to turn off heating when the sun comes out.

Also slow to heat up, fitted electric UFH to mothers wet room with the idea it would dry the floor, total failure, shower would cool floor, and it would take an hour to warm up again and nearly 3 hours to dry unless you mopped floor after having a shower. It took around 3 hours to get to full 27°C which is maximum permitted which was not enough to keep room warm with the required size of extractor fan. With fan off, it had to be on 24/7 to keep room warm, lucky also had a towel rail.

So I think for an OAP home where you don't want hot radiators, and heating is used 24/7 the under floor heating may be really good, but the idea today is only to heat rooms as and when required, and under floor heating is too slow.