Hi,
I'm trying to decide on which combi boiler to fit in a 1 bedroom house with one bathroom with bath/shower (I may add a shower room in the future) and three 600x1000mm double radiators. I've been looking at the Ferroli Optimax II HE combi as the depth is small enough to be located in a cupboard space and it has a 5 year warranty.
This combi comes in 18S, 25S, 31C etc. capacities. I've read conflicting things such as "if it's too powerful, it'll always be cycling on/off which will be less efficient" and "the power of most combis can be adjusted so overpowered ones can be just as efficient".
I've had one quote recommending the 18 and another recommending the 25. Is there any advantage to getting the more powerful model? e.g. would I get hot water faster for a bath? The price difference between each isn't much. This particular boiler seems to be gas modulator which I believe means it will be efficient in low use.
I've also read that high capacity radiators are best as it lowers the return water temperature (thanks bengasman!), increasing efficiency. I'm planning to slightly oversize my new radiators because of this.
Thanks.
I'm trying to decide on which combi boiler to fit in a 1 bedroom house with one bathroom with bath/shower (I may add a shower room in the future) and three 600x1000mm double radiators. I've been looking at the Ferroli Optimax II HE combi as the depth is small enough to be located in a cupboard space and it has a 5 year warranty.
This combi comes in 18S, 25S, 31C etc. capacities. I've read conflicting things such as "if it's too powerful, it'll always be cycling on/off which will be less efficient" and "the power of most combis can be adjusted so overpowered ones can be just as efficient".
I've had one quote recommending the 18 and another recommending the 25. Is there any advantage to getting the more powerful model? e.g. would I get hot water faster for a bath? The price difference between each isn't much. This particular boiler seems to be gas modulator which I believe means it will be efficient in low use.
I've also read that high capacity radiators are best as it lowers the return water temperature (thanks bengasman!), increasing efficiency. I'm planning to slightly oversize my new radiators because of this.
Thanks.