How efficient are Storage Combination Boilers?

[jaynana]

some boilers have a small hot water storage capacity. one example is the Vaillant 937.

they provide instant hot water by having heated water in a small storage tank in the boiler.

question is, what if the water has not been used for a while? the water in the tank would then go cold!

do they constantly keep heating up the water in the hot water tank? - even when the water is not used?

that would hardly be energy efficient!

 

[ianmcd]

The internal cylinder is extremely well insulated and yes the boiler will keep it constantly hot, they are very good if you dont have too large a HW demand the boiler you mention is one of the good ones

 

[jaynana]

thanks