Gravity System But Programmer c-plan???

[ericmark]

I have been thinking about with a tank thermostat, where I have the problem is if tank thermostat calling for heat, and programmer is not, there was a mechanical link on the old programmers which stopped you turning the central heating on without also turning on domestic hot water, and as a result can't see how a tank thermostat can be added unless the person setting the schedule always sets the DHW on at same time as CH.

 

[adamfozz]

Looks like I have it working. It seems there is a delay between the pump starting and the boiler. I turned water off on the nest so that I was sure that the water wasn't activating the water and then I turned up the temp on the nest. The pump kicked in and about 20 seconds later the boiler too.

Thanks alot for all of your help!
Adam