immersion heater for central heating?

[centricx]

Am putting in solar and battery system. I know I can heat my hot water with an immersion heater, but can I also fit an immersion heater into the closed central heating system that is currently heated by my oil-fired boiler?

I can't find anything online about immersions in the wet central heating system. Is it possible? common? where would I fit it?!

 

[AdrianUK]

Well you could, but I think you're gonna be disappointed with the performance.

An immersion heater is 3kW. Your oil boiler - you'd have to tell us what size it is but probably in the regions of 15 - 20kW.....

 

[Taylortwocities]

Hmm. If only. In summary and in answer to your questions

Is it possible: yes but not at all effective
Common: no
Where would you fit it: you wouldn’t.

An immersion heater has a low power output. Usually about 3KW. A central heating boiler can have an output of as much as 10 times that.

 

[CBW]

An immersion heater will need to be immersed in water (hence the name) and I doubt you’d be able to fit it anywhere or get the right output. You might be able to fit a heat exchanger

 

[DiyNutJob]

3kw should be Ok for 3 radiators. I was using a 500w radiator and it was do-able with extra clothes.

 

[Harry Bloomfield]

I can't find anything online about immersions in the wet central heating system. Is it possible? common? where would I fit it?!

If you used a hot water cylinder, heating that up with the immersion element, and if it were very well insulated, you could pump that hot water through radiators as required, but the warmth would not last very long. Heat in, in Kwh equals heat out. A 3kw immersion might take 90 minutes to heat up 120L of water to 60C, so you would have maybe 4.5Kwh of stored heat. 1Kw per radiator, so one radiator hot for 4.5 hours.

 

[ericmark]

My brother in law had that system, two very large tanks with hot coils and immersion heaters so wood burner, solar panels, LPG could all heat the tanks, which in turn could heat the house.

But to be able to thermo syphon the tanks needed to be up stairs and the floor was reinforced to take the weight, since a new build this was not a problem, all part of the house design.

However as a retro fit the cost would rule it out, when he moved he did look at doing it all again, but looking at 30k.

Without solid fuel it would be possible to be on ground floor but still expensive. One would need a massive array to do much, it was not really intended to run the central heating, however when he visited his daughters in Germany one return there was enough to reheat house ready for his return.

 

[centricx]

ok all many thanks. Will park that idea for now!