Replacing a honeywell st9400c controller with a hive setup..

[simzep]

Hi, I'm about to replace my honeywell st9400c central heating/hot water controller with a hive system. I know that the hive can be attached straight to certain backplates of certain controllers. Would this be the case with mine? I have a conventional glow worm boiler.

 

[Boiler buddy]

No, the ST9400c backplate is rectangular, even though it’s single gang. You get ID stickers with the hive kit, make sure you isolate your electrics and identify which wire goes where, the plate should read left to right, N,L,1,2,3,4. Follow that and you should be ok, the only problem you may have is linking through the room thermostat in the wiring centre, to make sure the existing thermostat no longer has a live feed

 

[simzep]

Thanks for the advice, hopefully installing it tomorrow. We currently don't have a room thermostat, which is the main reason for getting hive installed.. So should be fairly straightforward..

 

[Boiler buddy]

Should be ok then, as your central heating on in the wiring centre from your programmer should go straight to the white on your mid position valve if there is no room thermostat. If you need any help Just ask

 

[simzep]

Thanks for the advice. Installed it today, all set up, nice and straightforward.. now to set the schedule.

 

[Boiler buddy]

Great, pleased the advice helped. Use the app, easy to set a schedule, geolocation is a good tool too.

 

[Calum Coomes]

Hi. I'm new here and was wondering if I could get some advice. Today I fitted a hive heating only system to my glow worm cxi24 combi boiler. Wired it all up. Hot water ok but when system called for heating it wouldn't fire up. Looked online at possible causes and like a numpty ended up blowing the options board. This I can get replaced no problem. The boiler still works for hot water but when I put the old stat back on to check it would work it still wouldn't fire up when heating was called.

Basically would the failed options board be the reason there is no signal going to the thermostat?

 

[Calum Coomes]

Basically just to let you know the current set up but when connecting black and grey common and load there is still no reaction from the boiler now.

N BLUE
L BROWN
1 BLACK
2 -
3 GREY
4 -

 

[Echo the husky]

In what way is the board blown up?

 

[Boiler buddy]

It all depends on where you put your black and grey, if it is on the voltage free connections(the small pink and blue wires on the PCB cover) and you linked from L to 1 on your hive this would create 240v on your volt free side. On a CXI there is a plug on your control board for 240v controls. If you can take photos I can probably help get a clear picture

 

[Calum Coomes]

So when I originally installed the hive I put the black on 1 and the Grey on 3 and then someone advised me to put a link in from L to 1. This was a bad move. There is a small pcb that has the L and N to it and some coloured wires that has a couple if resistors blown. I ordered a new one and it was called interface PCB. I'm hoping this is the only damage that has been done.

This morning the boiler wouldn't start at all and came up with a mixture of fault codes ranging from F1 F13 F16. Im presuming the failure of the small pcb would be the reason this is hapenning?

Unable to take pictures as I am at work until tomorrow morning.

 

[Calum Coomes]

Glow-worm 2000801923 interface card printed circuit board

This is the part that visually failed and am just curious as to what it's function is. Also hoping that it is the sole cause of my woes

 

[Boiler buddy]

All depends where your old control was wired to, if it went onto the old board on the 240v plug, can’t see why it went, but as I said if it was wired to the low volt/volt free connector, with two pink or pink/blue wires which are quite small and it was linked L to 1 this would of blown the resistors on the volt free switching. Let me know where your old control was wired to

 

[Calum Coomes]

My old control was wired to black and grey. Which at the boiler changed to pink and blue. One was in C and one was in LOAD. And that is exactly what it did. It blew the resistors. All black and crusty. So therefore I'm assuming this is why the boiler refuses to work and just by replacing this part of the PCB will bring it back to life?

 

[Boiler buddy]

No, you will need to change the interface board, and DO NOT link L to 1 in the hive. Put grey in 1 and black in 3,(doesn’t matter which way round) this will then make the hive volt free switching which should make the CXI fire ok.