Replacement boiler advice

[Seaside99]

Hello,

My Rameha Avanta Plus 24C Combi boiler needs replacing and I have been quoted for a Worcester Bosch 4000 30kW. We use two LPG gas bottles and we live in a small 2 bed house with three radiators (which we only use about twice a year, due to having a woodburner) and one bathroom. I did originally ask about the 25kW version since my existing boiler is 24kW but was advised the 30kW has a greater flow rate which I can see the advantage of and the price difference between the two is nominal.

Will there be any negatives to getting a 30kW (apart from the increased gas use when using radiators, I assume)? Will it use considerably more gas on a daily basis for just the hot water usage?

Any advice would be really helpful.

Many Thanks

 

[oldbuffer]

1. In theory, for boilers of equal efficiency, the amount of gas used to raise the temperature of water for either domestic hot water or space heating to the same temperature, will be the same. The only difference being that it should heat a bit quicker.
2. However:
2a. For hot water you may well use more if it heats quicker, and you may be able to use two outlets at once.
2b. For space heating there should be little or no difference.

 

[Johntheo5]

Your 24kw combi will give a flowrate of 11.5LPM at 40C from mains at 10C, the 25kw marginally more, 11.9LPM and the 30kw, 14.3LPM, if you are happy with your present flowrate then the 25kw will do the job fine but if if you require that bit extra then go for the 30kw.