Hi, just a quick post to ask anyone out there if you have any views on the following boilers:-

Worcester 30 cdi system boiler
Vailant ecotech 630 system boiler
Baxi Megaflow 28 he system boiler
and Veissman system boilers

We are having our old combi removed, and will be replacing with a system boiler and range unvented cylinder.  Each installer who has quoted has a differing opinion of which is better boiler and I am totally confused.   Can anyone help please.

Thanks everyone.

What thescruff said.

System boilers can be smaller than combi boilers because they have more time to heat up the DHW. Combi boilers effectively have seconds to heat the water as it rushes through the boiler on the way to the shower so they need to be powerful if you want a decent flow rate. A system boiler has perhaps 30-60min to heat the water in the tank so the power output can be lower.

A Combi sized to deliver lots of DHW will usually be more than big enough to heat the house - perhaps twice as big as necessary to heat the house.

Your new system boiler should be sized to suit the heating load and some additional capacity added to ensure it can reheat/recharge the DHW tank quickly enough.