fuse keeps blowing in wiring centre

[27oak]

Hi can anyone help

the glass fuse in the wiring centre in my airing cupboard started blowing randomly, after inital fire up of CH after the summer months, I have a standard gravity fed system?

changed motorised valve, (v4073a) and pump (grundfos) but still blows fuses randomly??

I have sort of worked out that if I switch on the CH only and let it get up to temperature and pump has switched off, and then hit the HW button fuse blows....... and vice versa

Hope above is clear

Any help would be appreciated

 

[picasso]

what amperage glass fuse are you using ?

 

[rojaca]

What blr and other controls do you have?

 

[seco services]

you not got a damaged pcb or burnt connections in the wiring centre ?

 

[27oak]

what amperage glass fuse are you using ?

fuse is 2amp

 

[27oak]

What blr and other controls do you have?

I have a baxi solo boiler (3 years old) standard programmer and roomstat

 

[27oak]

you not got a damaged pcb or burnt connections in the wiring centre ?

no all seems good, checked all connections all seem ok

 

[bhm1712]

something is drawing more than 2 amps in the circuit. you say you have replaced the pump and MV, so therefore something else must be drawing the current. if it only happens when you select hot water, then you need to think what is on the HW side.
what exactly is your system? is it a pumped CH gravity hot water or fully pumped? you say its a standard gravity system, but do you mean open vent?

does the pump come on for the HW?

normally, Heating systems are fused with a 3 amp not 2...

 

[seco services]

is it a pumped CH gravity hot water or fully pumped? you say its a standard gravity system, but do you mean open vent?

does the pump come on for the HW?

normally, Heating systems are fused with a 3 amp not 2...

i think the (v4073a) 3 port gives it away.

 

[picasso]

wrong conversion

 

[27oak]

something is drawing more than 2 amps in the circuit. you say you have replaced the pump and MV, so therefore something else must be drawing the current. if it only happens when you select hot water, then you need to think what is on the HW side.
what exactly is your system? is it a pumped CH gravity hot water or fully pumped? you say its a standard gravity system, but do you mean open vent?

does the pump come on for the HW?

normally, Heating systems are fused with a 3 amp not 2...

Hi, thanks for your response, I am a CH/HW novice, but i am almost sure that the system is a Pumped CH gravity system, the pump does come on for the HW, but goes off when up to temp, which i believe is correct??

I have 1 x honeywell v4073 mid position valve, (new powerhead)

 

[picasso]

was it doing it before you changed th head?

 

[27oak]

was it doing it before you changed th head?

fuse blew when switched on after summer, motorised valve was not working, so changed that, that is working ok now, but fuse still kept blowing, so i was advised to have the pump changed, which i did, but fuse still blows??

 

[picasso]

your wiring centre , does it have " honeywell smartfit " written on the front cover?

 

[bengasman]

Double check the wiring of the valve