Please can some experts advice me on boiler replacement size for a regular size 3 bedroom home feeding 7 radiators. The boiler will be fitted inside a kitchen cabinet with rear flu out the back. The boiler Ive been looking at is the glow worm flexicom 24hx. Please could anybody advise me if the size would be adequate enough to heat the house sufficient? Also what price would I expect to pay to install and test only?