Do I need to remove the back boiler before installing a wood-burning stove?

The question

When removing old open fireplaces in order to install a wood-burning stove, it is fairly common to encounter an old back boiler. This is a boiler system designed to take heat generated by the fire and transport it to heat radiators or water in other parts of the property.

It usually takes the form of a shoebox-sized boiler behind your fireplace and will be connected to a cylinder.

The question is, does this back boiler need to be removed during the stove fitting process, or is it simply enough to dismantle and disconnect the boiler from the system and seal the pipes?

The answer

Regardless of what measures have been taken to decommission the old boiler, it is very important to remove it before fitting your woodburner. The reason for this is that leaving the boiler in situ can cause an explosion.

With the pipes and boiler sealed, the heat from the woodburner coupled with any residual moisture in the boiler will lead to pressure building inside. The outcome can be a potentially fatal explosion.

NOTE: This applies even to back boilers that are no longer live and disconnected from the plumbing system. A Health and Safety Executive warning updated previous industry advice to recommend a total removal of the boiler.

The solution

As alluded to above, the first thing to do is to get a plumber to disconnect and remove the back boiler.

Some people want to keep the back boiler for reasons of convenience and not having to remove it. As we have established, that is not a safe or sensible option.

If the reason you were keen to keep the back boiler is because you wanted to take advantage of the opportunity to heat your radiators and generate hot water using your wood-burning stove, the solution is to install a specialist boiler stove.

This is a wood-burning stove that comes with its own back boiler, which can be plumbed into your heating system and achieve those results.