Copyright 2007 to 2016 Michael Bryant

Replacing an istor boiler...

I am asked from time to time which boiler would make a goods replacement for an istor. Unfortunately there isn't a single good answer to this question. 

Unfortunately replacing an istor can never be a straightforward 'like-for-like' changeover as the flue fitted to an istor cannot be connected to any other boiler (not even a new istor, as the istor is a discontinued product).

The Glow Worm Ultrapower SXI (Google it!) is the closest equivalent boiler in the same format. Fitting one will involve installation of new air supply and flue tubes from the boiler to outside - rarely straightforward unless the boiler is against an outside wall. Usually the old flue has been installed above the ceiling, and fitting a new flue involves cutting away the ceiling to fit the new, followed by repair and re-plastering and re-decorating.

To avoid all this the other option is to fit a wall-hung combi boiler on an outside wall, say in the kitchen. this is still not straightforward as the water and gas pipes will need to be extended from the original istor location to the new combi location.

A third possibility is to abandon gas heating and fit an electric boiler. These can still heat the radiators but although maintenance of electric boilers can be far simpler (no servicing or gas safety certificates - attractive to landlords) running costs can be astronomical compared to gas. Research the running costs carefully before making this decision. 

First published 8th January 2015
Last updated 8th January 2015

Copyright 2015 Michael Bryant