Internal fuse keeps blowing when i connect HW zone i to my wiring centre!

[chris watkins]

Have you taken Lr to the Grey's on the 2 ports & Ls to the Orange's ?

 

[Brambles]

You must be GSR to access behind the casing of your boiler.

Have you wired the zone valves for 240v or low volt across the micro switch?

Sounds like you are calling for heat with a 240v signal across a low voltage jumper. If so you are lucky that the fuse is acting before the pcb is damaged

The fuse on the pcb is to protect the board against a fault in the 240v circuit, not to protect against 240v being sent into a low or no volts input

 

[Murdoch]

I suspect there is more to this than the OP is telling us .............

 

[John Smiley]

Yeah i have a multimeter. I think i have mixed up between my 2 tank stat cables and valve cables. I had to extend the valve cables a few meters in flexi conduit come up a wall and through to the back of my wiring centre.
I did mark my cables but only with T1...T2 for tank valve 1/ tank valve 2 and S1 and S2 for both tank stats. I must have got them mixed up. (the boiler is in a dissused area which has no lights so been using a crap LED workligh)I am going to bell out all the cables from scratch tomorrow.

Zone valves are wired 240v accross micro switch. Boiler isnt giving me volt free contacts. Its giving me a Live supply and Looking for a switched live. The central heating valve and thermostat are working fine. The minute i connect a hot water valve with a tank stat it blows the internal fuse again.

As I said im going back tomorrow night to check for continuity and identify all my cables again.

 

[ShaunCorbs]

thats because the boiler isnt volt free

 

[Brambles]

John

LS LR on your boiler pcb is a low volt / no volt jumper connection. You actually pointed that out in the second paragraph of your initial posting.

Control valve micro switches should be wired low volt / no volt too.

 

[Murdoch]

As I said im going back tomorrow night to check for continuity and identify all my cables again.

Interesting comment ........ I had read this as it was your own home, but are you doing this for a paying customer?

Are you a spark or GSR?

 

[Harvest Fields]

Just because he says Ls is low voltage doesn’t mean it is. As you are talking about LS and LR and clearly don’t know what you are talking about he needs to get a GSR in to remove the boiler cover and correct the wiring which is clearly wrong by the sounds of it.

 

[Harvest Fields]

Im a spark doing it for my uncle. Its a void guest house. Ls from boiler is 240v..and Lr is a 240v switched live. Im going to sort it tonight. Ill let you know what the f**ck up was. Thought id have a bit more sense from the forum. But it was obviously a bad idea coming here to be pointed in the right direction.

I have posted the best sense that I can give you above. Put the case back on the boiler and get a GSR out. Either your wiring is wrong or the boiler is at fault. Either way get a pro out.

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