Horstmann 423 Diamond Mechanical Timer

Description

I’ve had this Horstmann 423 Diamond timer for years – it’s one of those things I never thought I’d actually sell, but now it’s time. It’s a real gem, not something you see every day. The 423 Diamond was a staple in central heating systems back in the day, and honestly, it’s still one of the most reliable units you can find.

It’s been fully tested with live wiring before I took it out, so I know it works as it should. The faceplate is clean, with only a bit of wear – no dents, no chips, nothing that looks like it’s been battered. All the dials and switches work fine, and it’s easy to set up. No fiddly menus, no digital nonsense – just solid mechanical controls.

If you’ve got an old 423 Emerald or Diamond backplate, you can just swap it in and go. No rewiring, no hassle. I’ve kept it running for years on my own system, and it’s never failed me. It’s like a classic car – you don’t need to go flashy, you just know it’ll get you where you need to go.

I’ve included the main unit, the original backplate (if it came with it), and all the fixing screws. It’s ready to go into your system if you’re looking to replace a failing timer without a full overhaul.

It’s in great shape and I’ve used it for real, not just for show. I’m not selling it for a fancy price – it’s £45, but I’m not going to say that in the title, like I don’t have to. Just thought someone might find it useful, especially if they’re looking for something that actually works without all the tech nonsense.

Stourbridge, Dudley – it’s right there, just a quick trip to get it.