Replacing Honeywell D40 with BEOK313WIFI

[Griswold]

Hello,
Could be this has been solved on here already, but if so, I can't find it. SO any help much appreciated.
As per title, I am attempting to replace an old Honeywell D40 with a BEOK 313WIFI.
The Honeywell was wired as shown and I have wired the BEOK as shown in the second pic, bridging from terminal 4/L to 6, which I have found advised in various places.
But the new stat doesn't fire the boiler (a Worcester Bosch 38 CDI Classic Combi).
I was worried I had blown the boiler circuits by doing something incorrectly, but when I require the Honeywell, everything works fine.
What am I doing wrong?
Many thanks!

 

[CBW]

Well you’ve got call and switched mixed up for starters, but it could be that open and closed terminals are used instead? Usually on those, the 2 you have used are for underfloor heating.

 

[jackthom]

The online installation manual is poor IMHO.

I'd make sure the unit was in manual mode (ie we aren't relying on the timer) as in the instructions. Then use the up button to select a high room temperature.

I'd then expect either 1 or 2 to become live. TBH I'm not sure which if any.

If you don't have a multimeter, power off and then move only the yellow wire alternately into 1 and 2 to see what happens and report back.

 

[Griswold]

Thanks for your replies.
My understanding from reading around online is that ports 1 and 2 are for boilers with actuators, and that if you put the s-live into them it can cause damage to the boiler's circuitry.

 

[CBW]

Thanks for your replies.
My understanding from reading around online is that ports 1 and 2 are for boilers with actuators, and that if you put the s-live into them it can cause damage to the boiler's circuitry.

Yep, I’ve just read the manual. So you need to connect 5 and 6 to your boiler, which is what you’ve done, it shouldn’t matter which way as it’s a switch, but try it the other way, so link from live to number 5 and yellow wire to number 6.

 

[jackthom]

Deleted

 

[Griswold]

So I rewired as per Chris's suggestion, but no joy.
I then used a mains voltage tester in the Close (1) and Open (2) ports, both when the thermostat was calling for heat and when it wasn't.
First, when it wasn't calling for heat, Close gave a reading of 220+V and Open read 36V.
Then, when the stat was calling for heat, Close gave a reading of 36V and Open read 220+V
Pictures showing this attached in the above order.
Here's a weird thing, though. As I took the readings, the boiler fired up, when the called for temp on the stat was lower than the ambient temp (ie the first stage above). The read out on the boiler flashed between a rising number, as the heating fired and the strange symbol on the last photo here, which doesn't feature in the boiler manual as far as I can see. Then, when I turned up the called for temp beyond the ambient temp (as per second state of voltage tester process), the boiler stopped working again, the strange symbol stopped showing and the number on the boiler dropped again.
I'm foxed, but I'm sure this must make some sense to folk more experienced than me.
Thanks again for your input!

 

[ianmcd]

Every time you cut and restore the power to your boiler , it will come up with that display for about 15 mins or so, it is the boiler doing the condensate filling mode , you cant over ride it, engineers can but dont try it yourself, just let it do what it does

 

[ianmcd]

Post better pics of the wiring connections at both ends of the cable, that tester you are using is as much use as a chocolate fireguard

 

[Griswold]

Thanks for your responses, Ian. I'm very fond of my chocolate fireguard!
Doesn't the changing voltage read out on the Volt-o-Meter 2000 at least suggest something is happening? Or is it so useless that it's completely untrustworthy?
I opened up the boiler's electrics, and I guess because it was moved a few years ago, the lines going into it are not a match for those going into the thermostat. Fiddly to get to, I'm afraid, so poor pictures again, attached (along with a clearer one of the stat's wires). The two lines of white flex appear fro the wall, all the rest head further into the boiler. Only Black, Brown and Earth coming from the one to the left Black, Brown, Earth and Grey from the one on the right.
Can anything be discerned?
Thanks again.