I am looking to replace my 12 year old Glow worm 60FF with a condensing boiler in my 4 bedroom, 2 bathroom detached house.
The 60FF has a stated max heat output of 18kw. The total radiator output is calculated at 14kw (15 radiators), I've recently had cavity wall insulation fitted, the house is double glazed with good loft insulation, the current boiler has always managed to cope in the past with all but the most coldest weather and hopefully the wall insulation will improve this.
However I have had the following contradictory advice and i'm getting confused about the most appropriate replacement. Any advice/clarification would be appreciated from you knowlegeable bunch out there!!
I've had the following advice so far:-
Glow worm advice - direct replacement is 24HX Flexicom, same gas supply pipe diameter 15mm, heating flow/return 22mm, rear flue.
Local Installer 1 - 24HX will be too high an output and could cause a kettle sound in the 22mm output pipes, receommended 18HX same output as current boiler.
Local Installer 2 - Recommend Worcester Bosch Greenstar 24Ri, but will need to bore new flue or lower position of boiler (currently rear flue), install 22mm gas supply pipe.
British Gas (think of a price and double it !!) - Worcester Bosch Greenstar 24Ri, but will need additional work to convert to 22mm gas pipe, bore new flue and convert to 28mm fully pumped (6m head) ??
I have read that condensing boilers should be worked as close to full output as possible for maximum efficiency, is this true.
Any advice would be appreciated.
The 60FF has a stated max heat output of 18kw. The total radiator output is calculated at 14kw (15 radiators), I've recently had cavity wall insulation fitted, the house is double glazed with good loft insulation, the current boiler has always managed to cope in the past with all but the most coldest weather and hopefully the wall insulation will improve this.
However I have had the following contradictory advice and i'm getting confused about the most appropriate replacement. Any advice/clarification would be appreciated from you knowlegeable bunch out there!!
I've had the following advice so far:-
Glow worm advice - direct replacement is 24HX Flexicom, same gas supply pipe diameter 15mm, heating flow/return 22mm, rear flue.
Local Installer 1 - 24HX will be too high an output and could cause a kettle sound in the 22mm output pipes, receommended 18HX same output as current boiler.
Local Installer 2 - Recommend Worcester Bosch Greenstar 24Ri, but will need to bore new flue or lower position of boiler (currently rear flue), install 22mm gas supply pipe.
British Gas (think of a price and double it !!) - Worcester Bosch Greenstar 24Ri, but will need additional work to convert to 22mm gas pipe, bore new flue and convert to 28mm fully pumped (6m head) ??
I have read that condensing boilers should be worked as close to full output as possible for maximum efficiency, is this true.
Any advice would be appreciated.