I have a Potterton oil fired combi boiler its ok on the heating but absolute rubbish on the hot water supply.
Can it be stripped of the combi parts and used as a conventional boiler and add a invented stainless steel cylinder as its about 7 years old

Brian, March 2011

The problem is it's a combi, when the heating cuts in it takes the heat away and theres not enough for the hot water heat exchanger three way valve works ok flow switch ok. We get round this problem by manually switching off the heating via room stat then hot water not to bad. What hassle when you just want to run hot water in the kitchen sink. Boiler manual shows 7.5 ltrs a minute WOW If the house is up to temp then somtimes it's ok it's just pot luck

Brian, March 2011

you don't need to strip it down simply leave one or two taps on the combi and re-connect all the others to the unvented cylinder first though i would check why the present h/water is rubbish (you have'nt said) next compare price of unvented cylinder plus fittings and labour against price of a new boiler there may be very little difference and whilst you're improving your h/water output you're decreasing the efficiancy and increasing maintenance costs

brian, March 2011