No power at programmer

[lxbn]

I have a problem with my Drayton LP241 programmer as it has no power ie all lights off. It is a gravity CH system, Worcester Bosch conventional boiler, the system has two motorised valves one for CH the other HW. All these controls are in the airing cupboard with the hot water tank.

This morning noticed that the heating didn't come on and saw that the programmer had no power. The programmer is powered through a 3amp fused spur. The spur is also wired to the immersion heater switch. Checked the fuse and it had blown. Changed the fuse and switched on - the programmer came on very briefly, heard one of the motorised valves start to operate, then the fuse blew afer about 1 second.

Any ideas please? Is the problem with the programmer, a motorised valve or a short in the box where all the wires from the spur, valves, and programmer are? The system was working fine, nothing was touched before this happened.

 

[seco services]

pos that your pump is causing it to short.

 

[seco services]

and your spur shouldn't be coming off the immersion spur as that is already 13 amp.

 

[twgas]

problem with mv, pump or boiler
if you have a meter to test components, disconnect and test them one at a time. if no meter but plenty of fuses turn bits on until fuse blows, repair and try again. I'd start with pump.

 

[lxbn]

The boiler, pump and programmer are about 2 years old. Of the motorised valves one is 2 years old and the other much older. Can a motorised valve be the cause? Also the immersion heater being run from the same spur does not help - would a short in the immersion cause a problem. The immersion was off though. Sorry I don't have sophisticated tools to make any meaningful checks.

 

[seco services]

the immersion wouldn't be the problem. it's just that you have spured of a spur. the immersion should be on it's own
it could be the mv but i would go for the pump first.

 

[WDIK]

do you have 2 seperate spurs? one with a 13A fuse and another with a 3A fuse?

if so its probabley one of the motorised valves as these usually move to energised the limit switchs, but it depends how its been done.

 

[lxbn]

do you have 2 seperate spurs? one with a 13A fuse and another with a 3A fuse?

No. The mains comes into the 3amp spur. The programmer is powered from the spur (though the junction box with all the other cables from thermostat, MVs etc. as decribed in my first post) not via a plug but a flex directly into the front of the spur. From the spur a heavy duty cable leads to a switch which switches the immersion on/off. This switch is quite bulky but in an awkward place so can't get a good view of it, it's old but I doubt anyone would put a fuse in that - certainly nothing to be seen from the outside. So there does not seem to be a separate spur for the immersion. Not ideal but that's how it is and has been for years before even my time.

 

[WDIK]

the imersion will draw 12.4 AMP

ensure its switched off and try again, thinking about it,
what some clever devil has done is use the immersion feed that went directly to the double pole switch (fused at the consumer unit) fed off the dedicated immersion circuit and tapped off for the spur but best to check the obvious first
hopefully its tapped off the incoming side of the spur

 

[lxbn]

Problem fixed - seco services got it right, it was the pump. But it took the corgi registered plumber 4 and a half hours to arrive at the conclusion and change the pump. At one point he was convinced that it was the PCB and he removed it and was on his way to get a new one. I was a bit skeptical as I had debated the merits of the Worcester Bosch in this forum before installing it about 3 yrs ago and the comments were good on reliability. So I decided to contact Worcester Bosch and the technical person asked to speak with the plumber. That was a close one - almost replaced an expensive part that proved to be OK. So a word of praise for Worcester Bosch who couldn't be more helpful. I must say the plumber is a decent bloke and I'm sure wasn't trying to con me - but because of the time he'd spent, it's cost about twice what it would have been to replace just the pump. I only wish he'd had the intuition that seco services had.

 

[WDIK]

goods result, yes Seco is a good guy and carries with him a great deal of respect.

 

[seco services]

glad you got it done
but 4 hours to suspect the pump is abit much,but everyone has different ways of checking for faults i surpose.

 

[superdupergasman]

glad you got it done
but 4 hours to suspect the pump is abit much,but everyone has different ways of checking for faults i surpose.

When in doubt get a big bag of 3 amp fuses and start disconnecting things till it stops blowing!!!