Back boiler and fire have to be compatible, you cannot just fit any fire. Some back boilers only have a choice of 1 or 2 fires.
The boiler manufacturers instructions should tell you which fires are compatible. If you let me know the make and model i may be able to advise more.
Replacement fires aren't cheap normally Â£300 - Â£400 what you have to ask yourself is - how long will the boiler last, is it in good working order ? is it worth spending Â£400 on a new fire or would it better to save and install a combi and a new fire (there'll be a lot more choice of fires and most people prefer the inset fires)
and the boiler is one of the following - Baxi Bermuda 45/3 OR 57/3
I guess it looks like I'll need a new fire and boiler. Not sure how long it's been fitted but the date range on Baxi website is 1996 -2002 so somewhere in between there. Do you think it's better to get another fire with back boiler or is there a better solution?
You're talking between Â£400 for a radiant fire to Â£800 for a more decorative fire. Alot of money to spend on an old boiler, i would recommend saving and getting a new boiler and fire.
The type of heating system you require depends on the size of your house and the number of bathrooms, you have a choice of a system boiler or a combi boiler. For an average 2/3 bed house and 1 bathroom - you can get a combi boiler from Â£550ish.
There's alot of gas fires to choose from. Most people prefer live fuel effect inset gas fires.