Swap oil boiler timer with immersion timer??

areidy

Hey guys, not sure if i'm going nuts so would like some help please. Pics below if it helps... Want to change out a Drayton SM1 (as it only turns on and off twice a day) with an APT IMM24. Can i do this or do i have to change like for like?? thanks

Irish Steve

They are both very basic timers, if the APT does what you need it to do, then there should be no problems with doing that swap, the main difference is that the APT does not have the option to be on from time 1 to off at time 4, effectively ignoring 2 & 3, but it can be set to switch on for short periods several times a day. If that does what you need, then technically, it will work,

Presumably, the boiler can't be split for hot water or heating, it's all or nothing, or are there other controls elsewhere, if there are, then a more capable timer might be more suitable.

areidy

Thanks Irish Steve, i thought this was the case but the wiring in my place is a disaster, been here 6 months and still trying to figure out how some things are even working!! I think the wiring in the back of the Drayton threw me. We don't have any thermostats or split heating setup. Also, the switched spur is wired after the timer! Been a long time since i was a leccy but this can't be right...

Irish Steve

areidy wrote: »

Thanks Irish Steve, i thought this was the case but the wiring in my place is a disaster, been here 6 months and still trying to figure out how some things are even working!! I think the wiring in the back of the Drayton threw me. We don't have any thermostats or split heating setup. Also, the switched spur is wired after the timer! Been a long time since i was a leccy but this can't be right...

That sounds strange, what's connected to the spur? if it's the pump or the boiler, then that's sort of OK, though normally, these devices would be hard wired rather than on a switched circuit. It could be that the switch is for the pump, and the hot water circuit is gravity circulation rather than pumped, so that's how the radiators can be off and the hot water on for summer use. The best way to determine that will be the routing and size of the pipe going to the hot water cylinder, if the directions of the pipes are avoiding horizontal runs, and are using 1" pipe, then it could be that is how you can split the 2 systems. If that is the case, there's no way to have radiators on and hot water off, but the other way round will work.

Another way to tell will be if there are 2 pipes going in to the bottom of the boiler, and the relative sizes of those pipes. If it is a gravity system, the pump will be on one of them, and the other pipe will usually be larger.

Sorry if that seems slightly vague, it's been a while since I've seen a gravity system, and describing it accurately in words is proving to be harder than I'd like.

Hope that helps a little. Good luck with it.