Water Heater Switches

tlinn91

Water heater help needed please.

I am struggling to work out which switches need to be turned to operate the OSO unvented heater in a flat I have just moved into.

There are 5 switches near the heater in the airing cupboard (Excluding the light), as numbered in black in the attached photos. Switch 3 is labelled as an isolator and I assume two of the remaining switches are for the two heating elements in the tank (One for the bottom off-peak heater and one for the boost). There is no controller, and without labels, it is hard to understand what the switches are for. I don’t want to keep everything turned on without understanding the impacts, so I need to figure this one out.

Probably a long shot, but it would be great if someone can help shed some light on what these switches might be for and what I need on for the water heater? I’m a complete rookie with heating/electrics so any help would be much appreciated please.

grumbler

My immersion heater switch isn't fused. A fused one is for the bathroom fan.

nofoollikeold

1. Normally keep the lower immersion heater switched on permanently - assuming you have a cheap rate source such as Economy 7.  That will heat the full tank up overnight, and will probably give you enough hot water for the whole day.
2. Leave the switch for the upper immersion heater off, unless you run out of hot water and need to boost the top third of the cylinder.  Costs two to three times the rate of Economy 7 electricity. 
3. Either immersion will switch itself off once the water has reached it pre-set temperature, normally around 60 degrees.  

tlinn91

Cheers for the replies. Sounds like the switches for the immersion heaters are probably the ones on the right (4&5 in the photos). We are on Economy 7 so will figure out which one is for the bottom heater and will see if it does the job on its own over night. Thanks for the help, much appreciated.

Homer_home

Chase the cables for switches 4 and 5 and see where they go that will tell you what heater is which 

As for the other 3 not a scooby doo , you can check the fuse box to see if anything is labelled and turn it off to see if the lights on 1 and 2 go out 

In your last pic is that a fuse box sideway?

tlinn91

Cheers. Found which switch was for the lower heater and seemed to do the job overnight.

Yeah the fuse box is sideways and has no meaningful labels unfortunately.