Why does my fusebox trip out when i put the C/H on

[j4ffa]

Right i have a ideal classic lxff & ff fanned flue gas boiler anyway its been running fine lately but today somethings wrong went to put the C/H on as we have and it didnt come on so checked the boiler and nothing checked the fusebox nothing so checked the upstares and noticed the power light next to the imersion heater wasnt on so changed fuse and it kicked in yay. So didnt think anything of it then maybe 5min later the power trips so i went to check and when i tried to put it back on it would trip again so i turned off power to the C/H and it stayed on so then moved the switch and again power goes off.

So im stuck we have no heating so after ideas on what it might be and how to fix or would i need to get a plumber in to solve it and fix??

 

[JohnD]

when you say your fusebox trips, you mean one of the devices inside it trips. What is printed on the thing that trips?

Where is this fuse that you changed?

"moved the switch" What switch?

 

[j4ffa]

You know the main fusebox in the house if the RCD switch for the C/H is on the main RCD trips off and if i turn the C/H RCD off then i can turn the main RCD switch on and it dosnt trip off.


The fuse i changed was in the airing cupboard you have the water heater panel and then a central heating panel with the off on switch theres a off switch and then a fuse panel well thats where i changed it on the central heating panel i can get pics if needed. next to the central heating panel theres a white box with all the wiring in which leads to the imersion heating and then to downstares

 

[JohnD]

what is printed on these two devices that trip?

 

[MrPlumbician]

If rcd trips, it's a neutral to earth fault.

Has anything got wet lately??

 

[j4ffa]

huh i said the central heating RCD and if thats on the main RCD trips but if the central heating RCD is off the main RCD dosnt trip.


We had a little leak from one of the drain valves in the airing cupboard and that leaked into the kitchen but i fixed that and since then its been fine.
Any idea where to start looking? would it be in the wire box in the airing cupboard or would it be on the fusebox.

 

[gigz]

Is it gravity HW and pumped heating ? If so it could be the pump.

 

[JohnD]

If you tell me what is printed on the two devices that trip, I can make an educated guess.

For example the might say "B32" or "B15" or they might say "30mA" "80A" and there might be a T or test button on one or more of them.

 

[j4ffa]

I had the pump replaced not long ago as it went and got told its a part that often goes

 

[JohnD]

<gives up>

 

[kidgreen61]

What's printed on the two devices that trip?

We're gagging to know

 

[j4ffa]

If you tell me what is printed on the two devices that trip, I can make an educated guess.

For example the might say "B32" or "B15" or they might say "30mA" "80A" and there might be a T or test button on one or more of them.

I didnt see that just now brb will check

heres the fusebox

If the central heating rcd is on the main switch trips and if the central heating rcd is off it dosnt

 

[kidgreen61]

Well there's a surprise, the CH switch has tripped.

Pump, div valve, boiler fan not necc in that order.

 

[j4ffa]

Well there's a surprise, the CH switch has tripped.

Pump, div valve, boiler fan not necc in that order.

I turned that off because if its on then the main switch trips

 

[kidgreen61]

Then you've found your fault, you just need to narrow down which component in the CH system is defective.