PCB Fuse blowing on Potterton Suprima 30 - 80

[fjh]

My wall mounted boiler has recently started blowing the fuse (rated 3.15A) on the circuit board. I've taken out the board and checked for burning or scorching, nothing evident.

I've replaced the fuse with a 4A to see if that changed anything and it still happens.

Up to 48 hours ago I had no problems with the heating.

Any ideas?

fjh

 

[breezer]

putting in a bigger fuse is not the answer, a fuse is there to protect things, you must have a short some where, look for any chfed wires, or else something is starting to draw too much current, perhaps you could try all options of your heating to see when it goes. ie, just hot water, just heating, etc

 

[CH4]

fjh,

You might try disconnecting everything from the PCB except for the mains supply. If the fuse still blows when the power is switched on then you will know that the PCB is faulty. Otherwise, you may be able to identify the cause if the fuse only blows after a particular external component is reconnected.

Before doing any tests, double check that you have been supplied with replacement fuses of the right type. They should be Anti-Surge (identifiable by a 'T' on the cap) and not Quick-Blow (identifiable by an 'F' on the cap).