Honeywell ST699

Product Information

PF Community Forums General Off-Topic Chat For Sale & Wanted Make a suggestion about the forum in general Do you have a multi meter and able to trace the wires, in theory one core provides the live input to the boiler (#8) and one the live input to the pump (#3). I can see from your photo that there are two separate cables as the wires going ino terminals 1,2,3,4 on the ST9400 as they have slightly different characteristics If only 3 & 8 were originally connected as per pdf .... For a gravity HW system, the hot water coming on fires up the boiler and the central heating being on powers the pump. To get you up and running should require the following links on the ST9400C

I assume the current picture of the ST699 is after it has been removed from the wall and it's sitting on a table so to speak. You had a hard wired link between Live, 5 (common for CH) and 6 (Hot water on). That's why I thought your hot water was permanently on. There was also a hard link between 3 (CH on) and 7 (HW off). Then there were connections to all four terminals for CH on/off and HW on/off which is not normal. So I wonder if the other end of those wires go to the expected places. No, I meant "have" cables linking on the ST699 as they are still connected. So I disconnected the power supply, the boiler and the water and these were left connected. I can confirm the hot water was never permanently on and came on twice a day. We also have the option of switching on the emersion for water. You can have hot water only, but you can't have heating only - the hot water has to be on for the heating to work, although I have no idea how the two are connected from a system point of view...You have what they call BASIC SYSTEM 1 or 2. Gravity hot water, pumped CH and with/without room thermostat. Now just need to see how that maps to the ST9400. However you should ensure you know what went where on the ST699. The use of three blue cores, two brown cores and one red core coming into the ST699 is a recipe for confusion. Strangely enough the links between terminals is the least of the problems. Unfortunately the part did not fit, with the attachment being too large. This does make me wonder why you are advertising indesit parts, that do not fit I don't have any pics of the ST699 wiring - schoolboy error, I should have taken some prior to disconnecting, but I thought it was a straightforward swap so didn't bother.

to the terminals of the dual channel Hive that have exactly the same functions. So N goes N, L to L, Hot water on, to Hot water on etc... As this information is anonymised and aggregated it cannot be used to identify any individual user actions. With the older type of systems, (without motorised valves) it's not possible to have the heating 'on' without the hot water being 'on' as well. These are usually older systems installed before 1980's, but can be upgraded. Changing the Hive to gravity mode just makes it automatically turn the hot water on whenever the heating is selected on. If so, you have a fully pumped system, but it's not being used to its full ability because the ST699 has not been wired correctly. Fortunately the changes I mentioned (motorized valves!) will not be necessary. It's just a case of installing a new programmer, correctly wired, and a thermostat.As you say, the junction box on the floor is just to extend the cable from CH valve, so it doesn't hang in the air. This has lead me to think that while I'm replacing valves anyway I may as well use the opportunity to fit Thermostatic valves to all the upstairs radiators. I always thought I would need to replace the boiler system to get these but (unless I'm very mistaken) it's just a case of swapping the valves on the existing system. Not so worried about downstairs but our upstairs rooms are very prone to overheating and I think TRVs would really help and save money. Whilst wire colours do necessarily mean anything on a central heating system, the combinations you have are a bit unusual. For example blue being used for CH on & HW on and brown for hot water off. That's based on your indication above about wiring on ST699. If you have a S-Plan system with a single heating zone 3 for HW-On and 4 for CH-On, nothing to either 1 or 2.

The only reason I wasn't going to bother with downstairs was because we don't really have trouble with the heat levels downstairs, if anything it's hard to keep it warm even when heaters are on constantly as it is a large open plan space and has a very large bay window at one end and French doors at the other.We have good water pressure in the house so I don't think a combi would be a problem, however that's a couple of years off yet (or until the current one dies!). Also on your prior ST699 connections. The hard link from L to 5 means that when the hot water was "off" power would have gone across to 3 (CH-On)

I would really like to get rid of the thermostat in the hall altogether for cosmetic purposes and I would love to have more flexible control over the heating than the draconian timer we have now that has one setting for all days for both the heating and the hot water at the same time. Using "ST9400c Wiring 1.jpg" going left to right can you indicate which core went into which connection on the ST699 Ideally I would like a modern digital timer with flexibility for multiple programmes for different days and times and a wireless thermostat in the living room to control the temperature. And one that doesn't lose all it's settings whenever there is a power interruption! I opened up the Honeywell wiring hub near the boiler power switch to try to get a better idea of what the wires were doing Whilst Hive has an earth terminal it isn't actually connected to anything. Hive doesn't need an earth connection itself. The terminal is just there to 'park' any earth wires that happen to be present and keep them together so that they are safely out of the way of the other terminals.Just wondering if anyone knew what would be the best replacement programmer for the Honeywell ST699? Other than like for like.