System boiler better than a Comi Boiler?

Good evening, System boilers piped with hot water storage cylinders give you a greater flow rate (if installed correctly). With you having 2 bathrooms the demand for hot water is calculated to be greater than most combi boilers can achieve also you are more likely to achieve higher temperatures with most combi boilers only achieving 35°c rise from the incoming cold water temperature. If you want to guarantee instant hot water it would be better to leave it on all day but if you have a up to date cylinder thermostat and good cylinder insulation the heat loss is minimal and the boiler only comes on to boost the stored temperature. Hope that helps

for a 4 bedroom 2 bathroom house your hot water storage cylinder is to small,if you go for a combi you will be disapointed unless you have great pressure and volume even those combis the the makers say can supply 2 bathrooms will not,proper controls and insulate everything,most modern cylinders stay hot for 24 hours,if your pipework is properly sized and lagged heat losses can be cut down,and at least you will not get water starvation in one bathroom when using the other.