Worcester Heatslave 26/32 advance hotwater function, why?

[ottosump]

Hello group, we recently moved into a property which has oil fired central heating, the boiler is a Worcester Heatslave 26/32, we've never had oil before and were just seeking clarification on an couple of issues regarding the hot water advance function. Firstly, is it more economical to have this turned on, or off, what is the purpose of it? The previous owner told us that it was best to leave it on as the hot water would take ages to heat up if disabled. We can hear the unit kicking in during the day and night, presumably heating the water up, is there a reservoir inside the boiler, and if so what capacity will it be?
Thanks group, any advice gratefully appreciated.
Otto in West Cumbria

 

[dcawkwell]

Set the timer to switch the hot water off during the night unless you want hot water durin gthe night.

The advance has no function for an oil combi boiler.

The boiler has it's own heat store inside that it uses to heat hot water coming from the mains. It is therefore necessary to keep this hot
while you want water during the day. If you are out at work simply set the timer to have the hot water on when you are in the house. The boiler will heat the heat store up and be ready to supply virtually limitless hot water in about 15 minutes.
When the hot water timer is set to off you get no hot water as the boiler won't kick in to supply any.

 

[ottosump]

Thank you very much for the informative and prompt reply, it makes sense now, and explains why sometime we don't get hot water for the shower.
Regards Otto

 

[Burnerman]

Just for info, the heatslave tank holds around 10 litres (from memory) so even if the DHW is timed off, you can still draw on this stored hot water until its gone.
Saves the boiler coming on during the night to keep the heat level topped up, if you like.
John