Replacement Options

We currently have a System Mate 111 fitted in a cupboard, with the boiler unit on the wall (Maxol brand). The problem we have is that the flue is in the roof space and we have no access to it. Therefore if we want a new boiler fitted the only option we have is an outside wall in one of the bedrooms.

We are reluctant to do this, however looking over your site and reading up on thermal stores, I wondered if it was possible to replace only the thermal store itself without touching the boiler unit and if we did do this does that mean we can keep it in the cupboard.

We have a warning sticker from BG, but we have had that for 5 years or more since moving in. And doesn't alter our contract.

Any advice would be great.