New to Combi system, confused

[Minty_Cymru]

Hello all.

I'v recently moved home and we've gone from a back boiler to a combi system.

It's the first time I've ever had an experience with a combi and, although I love the convenience of it, I'm a little confused at one of the functioning states.

The combi is a Ravenheat CSI/HE 85 (model 85AaaT)

ok, so the front panel is simple, from left to right we have:

Hot Water/Heating & hot water switch (with reset)
Water Temp (with highlighted condensing mode setting)
Heating Temp (with highlighted condensing mode setting)
Timer
Power & Warning Lights
Pressure Gauge

All quite self explanatory, my confusion comes from the hot water only operation;

There is a switch on the wall next to the combi, with the switch on the power light on the combi is lit and we have hot water and if the timer is engaged or it is knocked on manually (conrolled via the timer) we also have heating. With the switch off, the light goes out and there is no hot water (obviously) however the timer is still finding power from somewhere.

Here's my question, what is the point of that switch on the wall if there is a 'water only' option on the control panel and the manual on/off/timed control only affects the heating?

Should I be knocking it on and off at the wall? Is there a danger in doing that?

Thanks!

 

[lame plumber]

combi means hw at any time, no programmer required, water only on panel is summer winter option to turn off heating, the wall programmer is for ch only, just leave the wall switch on. you can google your manual online to explain in deatail. ps start saving now for a new boiler, ravenheats are the budget of the budget models Im afraid.

 

[village idiot]

hot water should be on demand (in effect, whenever a hot tap is opened). Any external switching should be for the central heating, except you're reffering to switch that provides power to boiler? Regardless, the switch should be left alone.
If the heating timer is not properly installed, get an RGI from here to come have a look for you

 

[stevetheplumber]

are you sure the clock is going of display will stay alight as it has battery back up in it

 

[Minty_Cymru]

Ah, battery back up on the timer explains that.

Happily, the boiler's maintenance is covered by the tenancy agreement (we are renting) so that isn't a concern.

I just couldn't figure out why I'd need a means to cut the power to the unit while there is a water only option AND the ability to switch the heating off on the timer (Off/Timed/Constant).

I should leave it on then?

I did look through the manual although I couldn't find any references to a switch so I thought I'd ask.

Couldn't find anything about the 'Super Efficient Condensing Mode' either. This is apparently achieved by having the water and heating settings at the right points. Can anyone enlighten me?

Thanks for the help too.

 

[AWheating]

the mains switch/isolator is to enable the electrics to be turned on and off when needed. Its not ment to be used daily, more for maintenance etc.....

 

[Minty_Cymru]

Wicked.

Thanks for your time.