Danfoss Randall 4033 Electromagnetic Timer

The Danfoss Randall 4033 is an electromagnetic analogue timer that can both control heating and hot water separately. It’s a very old model that provides basic settings when compared to what the current day programmers offer. Reliability overall is very good, but the main thing that fails on this model, is the timer dial motor either stops working altogether, or slows down to a pace that makes it annoying, potentially noisy, and unreliable to use. But other than that, for the most part the 4033, particularly the older model in terms of the manufacturer date, has served many users extremely well, giving a good majority of them several decades of good service.

This is one of the main reasons why some users want to play it safe and buy the same model again. And this is possible even today. The 4033 is still available for sale online from eBay, Amazon UK, and several other plumbing outlets.

However, for some people that want to get a bit more up-to-date and want a few more features at their disposal when it comes to central heating and hot water. This is where either a digital non-smart replacement or even a smart replacement may fit the bill.

There are many replacements available from the digital Danfoss programmers, to the Honeywell and HIVE Smart ranges, but most will require some level of DIY / electrical knowledge of wiring / heating systems to swap over. For some systems it won’t be that difficult, but for others it might require the help of a professional just to be on the safe side.

How to install and use: The PDF instruction manual / wiring diagram can be read / downloaded here. This is a free download and there is no log-in required to view or download the file.