Horstmann C21 Electronic Programmer

This worked perfectly, it was easy to set up. easy to read display. Bear in mind the switching timer is in 10 minute segments, which isnt a problem, it only makes things easier to change a time. One big advantage is you can set the HW and CH independently. you don't always want the heating on at the same time in the day as the hot water. I also have found the clock to be very accurate and has a date setting too. and the biggie is a 3amp switching which means I can use one of these controllers for a completely different purpose. lovely product.

Bought this to replace a C21 unit which had developed a fault. New unit slotted straight into existing contacts plate and worked perfectly.

This programmer replaced an old electro-mechanical programmer. The clock had stopped working after over thirty years so fitted this new one. It simply fitted onto the original single patress box and then wired as before taking into account the simple instructions provided. Job done and looks good.

Yes, it's OK but I nearly returned it to Amazon as it would not fit onto its backplate. However, I persevered and, with my innate skill, fixed it and it is now working fine. True, the price was reduced as what I take to be an item that was 'used', although it looked perfectly untouched when I received it. Anyway, Amazon's returns policy is very good; no quibbling.

The programmer is not working and as such prevents the entire heating system ( ie both hot water and central heating ) from operating. My only option now is to purchase another programmer having only had it installed for a short period of time.

Oh joy, oh joy. For years we all struggled with my elderly Mum's old programmer, that's 2 people with degrees, an engineer and myself. No one fully mastered it and I finally persuaded her that as I live 70 miles away and tend to be the one she phones to get jobs done that we needed a timer that was easy to set and adjust. Having had Horstmann previously and currently I immediately opted for this one. Was set in minutes after fitting and as the cold weather sets in has been equally easy to reset since. I'd be confident I could even talk her through resetting it over the phone as it's that easy. The hot water boost and advance is equally handy. Brilliant.

First class programmer which is extremely efficient and solved all the issues which I was previously experiencing with my central heating system.

Bargain at £35 (2015). Easy to install and program.