Lp20rf not firing up cdi35 worcester bosch boiler

[Grifter]

I recently moved into a flat with a Worcester Bosch CDi 35 Compact (or Classic System maybe?) and the thermostat on the boiler was broken (the thermostat was visibly damaged). I replaced it with a Drayton LP20RF receiver and thermostat. The boiler guy came round once other work was completed to reconnect the gas and sign off the boiler - he said it all looked ok, but that was before I had got the thermostat connected and running. I have connected everything up now, and although the thermostat is requesting heat and the LP20RF unit is responding, the boiler never actually produced hot water for the radiators.

I have spoken to Drayton and they think the thermostat and receiver are working fine, and the boiler can make hot water for the taps, it just never seems to interpret the signal to come on correctly for central heating. Therefore I thought maybe I needed to do some rewiring inside it - I opened it up and I think I need to do something with the switched live and live return terminals, but I don't know where the signal wires from the thermostat (connected with a ribbon) are coming out...

Is it clear what I need to do, looking at the attached photo? I don't think I can afford the boiler repair guy coming out again (certainly not this month!) and it is getting really cold now, so I could definitely do with some central heating!

 

[ShaunCorbs]

😀 he never reinstalled the link that you require should link ls to lr

 

[Grifter]

😀 he never reinstalled the link that you require should link ls to lr

Just literally a connector between ls and lr - like if I took a 1.5mm2 wire with its sleeve from some cable offcut and used about 20mm of that to connect the two terminals, it would do the job?

 

[ShaunCorbs]

Yep

 

[Grifter]

It worked! Brilliant and amazing! This has made such a huge difference to my quality of life! It was looking to be a very cold Christmas, what with callout charges - Thank you so much! One small wire for the boiler, one giant leap for me! This is wonderful! 😀