central heating electrics problem

[johnsm]

my central heating programmer burt out and i replaced with a new one and it started to over heat so i took it out and bypassed it by joining up the three cables to get my central heating going,it works ok for a few hours and it then blows the 13 amp fuse at the power supply switch,does anyone know what is causing this and please help me and explain how to rectify this problem as its freezing up here in scotland.
and oblige johnsm

 

[toasty]

just a guess but I'm assuming a simple system with no cylinder thermostat.

The three cables at your programmer will be the mains in , boiler/pump feed and the room stat.

You've connected them all together (brown to brown, blue to blue, green/yellow to green/yellow) so all is fine until the room stat is satisfied, at which point it crowbars (shorts out) the mains and blows the fuse.

No offense, but as you don't seem to understand what you are dealing with it might be an idea to just set the room stat to a high temperature that your system will never reach (i.e 30 or so C) and wait until after christmas till you can get a plumber/electrician to fix it.

You can always regulate the temperature manually by switching the whole system off when it gets too warm and then back on when it's cold.

Good luck!

 

[breezer]

why do you suppose it burnt out ion the first place? there is something wrong and bodiging it will never solve the problem, you need a heating engineer to look at it.

 

[2face]

remove the 13 amp... should be a 3 amp...

all separate plug heads .

best temporary way is plug the boiler in.
plug the pump in .
manually open the zone valves.

the heating will work then only on the boiler stat but will get you through xmas..

this is purely temporary and should be sorted as soon as possible.

3amp max fuse size. !!!!!!!!!!!!

 

[Click-Sure]

Unless its an oil burning system, which generally use a 5 Amp fuse.

 

[2face]

general rule of thumb 3 amp to a f/spur 5 amp to a 3 pin plug.. (dont know why)

i always use a 3 amp .. usually plenty .. but yes as you say oil can be 5 amp .

 

[Lectrician]

general rule of thumb 3 amp to a f/spur 5 amp to a 3 pin plug.. (dont know why)

Where has that come from

 

[johnsm]

hi guys,i found the problem,it was a short on the boiler cable,because its a back boiler i had to strip the fireplace and remove the front of the boiler to get to it,the neutral wire was shorting against the the side of the boiler frame,the boiler was fitted over 20 yrs ago and the wire was pretty bad,it was hard and burnt,thanks for your help.
best regards john