Help replacing immermat central heating timer

BoobeR

Hi, I'm looking to replace my central heating switch but getting a bit confused. The timer switch pictured controls the heat to rads with on off and timer. Timer is now broken so I'm looking for a LCD replacement on the cheap. Preferably just screw that one off, wire in new one and job done. None of the Wi-Fi contolled electronic valve stuff.

I looked up that immermat one and it's listed as water heater (I assume immersion) controller ?? But this controls the rads and I flip another switch for immersion .. 2nd one down in other pic. The top switch I have no idea what it does. Is always on. Probably just to turn off immersion also, the bottom plug one controls the timer which is odd as the cable from the timer leads right into the top of that first switch. Maybe it's the power for the oil burner?

Anyway enough rambling but when I look for central heating controls I always find ones that you just set the temperature and it comes on at that temp I assume? Which would waste a lot of oil. We only turn it on when we need it or for a half hour to an hour to heat rads then the cooker will keep heat in the rads. Can someone point me to where/what I need to get? Again .. cheap preferably as my wedding is coming up 😨 Apologies for wall of text.

Thanks

cnocbui

I would say the top Switch in the second photo is likely for the boiler. Looks just like mine.

I got a programmable thermostat timer for my CH, placed between the outputs from the main switch and the boiler.

The one I got lets you program the times of day when you want the heating to be on or off and the air temperature you want the CH to heat to.

My CH is technically 'on' year round and I never touch it. It won't turn on if the air temp in the house is at or above the set temperature.

DGOBS

Replace with a horstmann centaurplus c11