Can I use a Boiler stove without connecting it to the water?

This is a regular question we get asked at The Stove Yard, and unfortunately the answer is definitely 'no' – not if you ever want to use the stove again as a boiler stove.

Stove boilers are made of steel or stainless steel, a much thinner steel than is used on the bodywork of a steel-bodied stove for example, and they require the cooling effect of the water as it passes through the boiler to stop them from over-heating and warping, which could potentially cause any welded seams to open up and leak. Operating a boiler stove without water would certainly invalidate any manufacturer's warranty but also provide you with limited heat, as the air in an empty tank also acts like insulation limiting the heat output of the stove. This would be most apparent in boiler stoves where the boiler is of the 'wrap- around' type. Some older boiler stove models (eg Broseley Hercules) use the actual boiler as the sides and back of the stove to maximise the heat to the room (like three large radiators) and therefore excessive heat to the thinner boiler steel without the protection of the water's cooling properties could also create a potential fire risk.

Elsewhere on the internet you may come across information where it says that it is OK to fill a stove boiler with sand. Again we would not recommend this, even if it could be done in the first place and you could then, somehow, get it out again. Any residual sand left after you want to revert to a boiler stove would probably wreak havoc with pumps, valves, radiators and any manufacturers' guarantees.

So, simply think of a boiler stove in the same way as you think about using your electric kettle – you'd never boil it without water and you'd never put anything else, except water, in it.