Choosing the right boiler

barrowvian

Hi all,

I've had a few different quotes (which I'm happy with), but my main question is to do with the size, kW and hot water flow rate, of the two boilers I've been quoted for.

My property is currently 2 bedrooms 1 bathroom, however, over the next couple of years we are planning on extending above the garage to make it 3 bedrooms 1 bathroom 1 en suite. We wanted to make sure the boiler would be adequate to meet our needs going forwards otherwise we'd have to upgrade the boiler at a later date.

At the moment there is an old Potterton Profile conventional boiler in so all that's going to be ripped out. I think the engineer said it had something like 8 kW output.

1st is a Worcester 30si Compact Combi
- 30kW heat output
- Hot water flow rate (l/min) @ 35 degrees = 12 and @ 40 degrees = 10
- Electrical usage when firing = 114W / Standby 1W
- Hot water heating efficiency = 75%
- SAP winter efficiency rating = 90.7%

2nd is a Worcester 36Cdi Compact Combi
- 36kW heat output
- Hot water flow rate (l/min) @ 35 degrees = 14 and @ 40 degrees = 12
- Electrical usage when firing = 130W / Standby 1W
- Hot water heating efficiency = 72.4%
- SAP winter efficiency rating = 90.7%

There is about £185 difference between the two boilers. I know it's not a huge difference but looking at the figures is it really worth it to go for the slightly bigger boiler in this instance? Or would the 30si be sufficient for our future plans?

Thank you.

Plumber90

If your going to have a bathroom and ensuite I would recommend a boiler and unvented cylinder, it will give you a much better hot water performance than a combi boiler.