CH wiring help needed. revamp of old system plus adding Hive

[Tattz]

Hi folks. ive been using/following this site for a while now while I renovate an old house I bought but this is my 1st post...

first the history: I have a very old system that hasn't been updated for probably 30 years or so. I have swapped out all the old (rusted/leaking/broken beyond recognition) plumbing connections and in doing so also replaced all the components for modern units (apart from the pump which seems ok) I have not moved anything the positions are all as before.

I believe it to be a fully pumped S plan system. 2 x 2 port zone valves and a large water fill and small F/E tank in the loft

I have bought a Honeywell sundial wiring centre to help me out which is pretty self explanatory as far as the connections are concerned.

so far i have connected everything apart from the cylinder stat, I was going to use the old switchmaster one that was there but this has different wires and i cannot find any info on it to determine which is which so i will buy a new one tomorrow and fit this in the wiring center shortly

so far i have snipped the links as per the instructions inside the lid and also joined the room stat terminals as i am not using one (the Hive should be taking care of this) when i switch on the power all is ok, both zone valves stay closed as they should and nothing blows up. But when i click for heating on the hive the system seems to start correctly but then blows the fuse in the wiring centre.

so 2 questions.

1 - Is it ok for the cylinder stat to not be connected for now
2 - and the elephant in the room! and the hell do i do with the Hive heating off wire (as you can see ive just put it in a terminal block while I ask you guys what ive done wrong lol)

if ive missed any relevant info please let me know . thanks in advance

 

[picasso]

What do you have the hw off connected to ?(black cable on the left to the programmer connection block)

 

[Tattz]

Hi Picasso, thanks for your reply. ive attached the wires as per the Hive dual channel wiring diagram (attached) or at least hope i have lol

so the L/N & earth from the Hive are in the RH cable. Hive terminals 1&2 (HW off black/HGT off red) are in the LH cable and Hive terminals 3&4 (HW on black HGT on red) are in the centre cable to the programmer block.

so if i move the CH on wire to room stat 3 what do i do with the CH off wire? does this remain unused and made safe?

thanks

 

[picasso]

Remove any connections to the hot water off and heating off terminals as you dont need them, you only need the ch on and hw on , leave the rest as is until you get the cylinder stat done.

 

[Tattz]

Perfect. thanks a lot for your help. i can pick up a new cylinder stat tomorrow easily enough so should hopefully get it all wired up tomorrow night. although i will need to try and find a new fuse for wiring centre, typically after a quick google they dont look something screwfix or similar would stock. hopefully the electrical supply shop might have some

I'll let you know how i get on

cheers

 

[Tattz]

Hi Picasso. I've wired in the new cylinder stat. (See pic) black is call for heat, brown satisfied, blue common.

When I turned the power on all seems ok nothing blows.

But when I pressed the hive CH button all looked like it was working ok, the pump came on and the CH zone valve opened but no hot water came through. I went down stairs to check the boiler and the pcb fuse had blow and by the time I got back upstairs the same had happened to the fuse in the wiring centre.
I must have something wrong somewhere but I cant see what.
The only other point of note is I havent taken out the wires from the Hive yet, (hgt/hw off)

I just disconnected them from the wiring centre and capped them off while I tested it. I was planning to sort it later, and not sure it should make any difference anyway

Any ideas? Thanks

 

[picasso]

You dont need the brown (satisfied connection) for the cylinder stat so remove it, what boiler do you have and can you post a pic of the boiler wiring ?

 

[Tattz]

Sorry for the slow reply

I'll remove the satisfied wire now.

I have a worcester green star 24ri. A pretty basic condensing boiler. I've attached pics below the fuse that's blown is top left of the pic. There is just 1 cable that runs directly to the woring centre

Thanks a lot

 

[picasso]

Remove the yellow/green cable from the LP connection as you have connected earth to the pump live.

 

[Tattz]

These are the 4 wire that connect to the boiler block in wiring centre.

The the green/yellow is in the earth of boiler block.

I take it the red tape means this isn't actually an earth wire?

 

[picasso]

It was probably used as a pump live but you have connected the other end (in the wiring centre to earth) remove it and see how the boiler runs as the pump is connected in the wiring centre,

 

[Tattz]

No power at all. In either the boiler or the Hive receiver.

I've just changed both fuses so they should be ok

 

[picasso]

Have you removed the yellow/green wire ? you need to check the fuse at the fused spur or plug for the whole system.

 

[Tattz]

Ooooooo your good. Lol bloody 3 amp fuse in socket had gone as well.

I've just done a system check and everything seems to be working as it should. All thermostats work correctly and all Hive controls seem ok.

You my friend are a bloody superstar... thank you very much for your help.

If your ever down Weymouth way let me know and I will buy you many pints.. (if we are ever let out again)

Just to finish am i ok to tape off and leave loose in the wiring centre the boiler green/yellow and the cylinder stat satisfied wires i have disconnected?

Thanks

 

[Johnmdc]

That boiler requires a pump over- run which is what that earth wire has been used for.
It should have some brown or red tape wrapped around it and connected to the P/L terminal with the rest of the boiler connections in the wiring centre.
You should also cut link 3.