Horstmann 425TIARA Programmer, Black

Product Information

I did it now - i thought that the outer plastic frame was already a backplate and that what got me confused. In principle the 3 channel will work if you alter the pin layout but since the original wiring is suspect one would need to be on site to make any sense of it. Obviously this isn't ideal, you get a real mess if you try and use the timers, as each pin does something it isn't supposed to. I'm sure it's not that complex but I like to know how things work in my head before I spend the cash. Thanks for the reply, I have got a friend checking it out tuesday and he diagnosed exactly what you said, he said that it will be the motorised valve more than likely.

It has 16 programmes available for fully pumped systems, including independent programming of heating and hot water as well as 10 programmes for gravity hot water/pumped heating systems.

I am exactly at the same stage of trying to remove the same panel and only see it being stuck solid to the backplate. The list should not be considered a complete list of all available, excellent central heating controls. There are lots of options, with a smallish number of variations, so if you decide what features you want we'll probably know of one which will do them. You want to have look at their controller for gas street lights, a work of art, clockwork movement is brass,.

You are right it’s not rocket science, I haven’t taken the cover of the old unit yet but I was a bit puzzled as to why I could not find a wiring circuit for this unit or any other correspondence for it online. currentley have the Horstmann 425 Coronet single circuit timeswitch and the thing can lose an hour or more over a few days, so we are constantley messing with it. Its difficult to understand why this programmer has been used if your CH and HW is not already separate.

Although it says "not user serviceable" I thought I'd have a looksee anyway - I'm not without some skills in the repair and replacement of PCB components - however I can't get the bloody thing off the wall. For instance, I *hope* the cabling to each thermostat allows for me to install the NEST power supply (supplies? No more damage to anything although I did need to fill and strengthen the partitioning wall around where my previous attempts had ruined the structure. Honeywell used to do programmers up to 4 or 5 zones, I think - now they seem to go with wireless room stats as you suggest.

I can get a screwdriver between the wall box and the stand-off but there's no way they are going to separate without my breaking one of them. And a pumped circulation for the energy to the radiators which is controlled by the pump being on or off.

Having checked thousands of central heating control reviews, we can say that the Horstmann is the best choice for most people. The whole idea is that the expansion of the hot water in the radiator / boiler pipework is taken up by an air pocket in the primatic hot water cylinder. Using the average ratings, you can check what all the reviewers think instead of just viewing the subjective opinion of one specific reviewer. If you are poking around with a screwdriver, make sure the system is isolated - there are live terminals near the top edge. The Tiara has all the programme capability and features of the 425 Diadem but without the indicator lights.

Personally I think they are fairly expensive for a mechanical basic clock, but they have been around for many years. When you remove your Coronet from the wall you will find all the wiring is attached to a backplate fixed to the wall, the Coronet clips and screws onto the backplate. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page. By pulling outward and generally downward I can clearly see the single wall box because I am dragging that towards me too. I also don't really understand how each of the two-way valves operate - whether the timer "job shares" between the two zones and whether two NEST thermostats can replace that functionality.in the hot tank cupboard (where the timer currently lives) and power each thermostat (remotely) that way. As others have said, the front is located on two lugs at the bottom of the backplate and hinges down from the top - you'd normally just pull the top towards you. Thank you KIAB for the tip, - I never have seen those Horstmann lights and certainly will keep an eye out for them. I really would not advise that this is done on your system without changing the HW cylinder and other changes to accomodate expansion.