keston c55 temperature control

[dudsbury6]

I have just had a Keston C55 fitted by a heating engineer. He has used just the zone 2 potentiometer (DHW?) to control the heat for the whole system. Keston tell me this is a non-modulating control and the zone 1 is the one that is modulating (i.e. I have a modulating boiler which is not modulating!). There is no information in the literature about this. Anybody have any information, please?
Also, with 1 set of flow and return coming from the boiler, how does the boiler provide different heats to CH and DHW, or know which is which? The pipework follows the correct layout for a sealed system, but the electrical circuit diagrams are not too helpful.

 

[Boilerman2]

Get the person who wired the boiler to swap Sw/L 2 to SW/L 1 (THe keston has to switched live connections one for HW and the other for Heating, he has connected to the wrong one.

 

[mikely]

Also, with 1 set of flow and return coming from the boiler, how does the boiler provide different heats to CH and DHW, or know which is which? .

Looking at the installation instructions, the boiler is intended to be wired in an S plan system which provides separate zone valves to control CH and HW. The zone valves provide separate switched demands back to the boiler (terminals SL1 and SL2) thus the boiler knows whether it is supplying the CH or HW circuit.

It sounds like you don't have an S plan system and thus can only use one control.