MrPotts

How can you get a return temp that’s higher than the flow? Unless the heat in the HW cylinder is being sucked out by the boiler flow. My return temps are normally about 10c lower than flow when heating the HW cylinder and about 20c when space heating.

OK, i think its time to get someone in that can investigate how the boiler has been wired.

Have you made all the connections to the boiler as per attached?

What’s the GC number of your boiler? Edit found it on post 1

If the link is still in place I think the boiler will think there’s is a permanent demand for CH hence why it stays on until you turn the boiler off.

It looks like the link is providing a permanent live to terminal 1 on connector X1 which looks like it is the CH demand hence the boiler runs continually.

So the connection has been made within the boiler to connector X1 position 1 and the link removed? This is going by what the boiler install manual says.

Sorry but I am confused now. You don't have the CH demand connected to the boiler so presumably CH isn't working? Maybe I missed something, again!

Sorry, I missed the bit where you said you had the browns together, yes that would also work.

Use the switched live orange from the NC valve to apply power to the NO valves live connection. Then when there is a call for HW the NC HW valve will apply live to the NO CH valve thus closing it.

If you watch through the video he describes how to convert an s plan to PDHW with a NO valve.

Good video here……..

In an arrangement where you have NC and NO valves the NC HW valve controls the NO CH valve. You just connect the orange of the NC valve to the brown of the NO valve.

We have the technologies but are being ripped off with the cost! Not many people have £20k to install PV and a heat pump.

Ignore me! Lock shield valves don’t always have direction of flow on them.