Baxi Potterton Gold Combi, Danfoss 715i clock and Stat

[crazyk69]

Hi

Just been to look at a property which has a Baxi Potterton Gold Combi boiler, the Danfoss 715i clock and a Horstamnn HRT3 room stat.
The owner is complaining when the 1hr boost is pressed the boiler doesn't switch off after the hour.
We have checked and everything seems to be working correctly, obvioulsy don't want to hang around for an hour to see if this is the only problem (which would be very strange).
Checked the wiring looks fine, is connected via a junction box as follows

Boiler BK 1 = No 3 (load) on Stat
Boiler BK 2 = No 1 Clock + No 1 (line) on Stat
the rest as per norm, N L vis a 3 amp spur etc,
Looks fine to me and the boiler responds to hot water and timer but the customer is complaining that it isn't switching off after the 1 hr but never said anything about it not switching off after the timer has been used, we checked this and it works.
Can anyone shed any light or is it just the programmer (it is quite new, not that means a lot )
Thanks in advance

 

[Agile]

Why not post in the trade CC section?

Or do you think that customers will have to help you?

 

[namsag]

Proper way to wire it is LNE from same fused spur as the LNE for boiler as i think you have done .
No links in the clock .

Out of boiler terminal 2 to terminal 1 on the clock backplate
out of terminal 4 on clock backplate to terminal 1 on your room stat
out of terminal 3 on roomstat to terminal 1 on boiler

 

[crazyk69]

Thanks Guys,
No don't expect customer to help

Thanks namsag, have found the fault, the stat has a fault, it is controlling the on/off of the boiler completely, we have checked the wiring again (doing it old way of drawing a diagram ) put a new stat on and it works.
thanks guys

 

[namsag]

Find it VERY strange that it is the roomstat as it is only a switch and should only have had power to it if the clock was supply in it
So after the boost hour from clock had timed out the internal circuit within the clock would break and no power would go to the roomstat and then on to the boiler

 

[crazyk69]

No
we took the wiring back to scratch and re-wired the clock and stat again as well, but the stat was controlling everything, then we found the stat had a short inside.

 

[namsag]

Your problem was the wiring then the stat fault was secondary for reason given previously