Reducing Furnace Cycling

[jpanhalt]

I never think it's a good idea to simplify at the start. It's best to understand a complex system and then simplify. Right now, you have a few goals in mind with simplicity.

Interesting approach. I have no concerns about trying to simplify so long as it works.

I am leaving in a few minutes for a couple of days. Attached are the electrical schematic and boiler diagram (done with Eagle).

John

 

[large_ghostman]

I think it looks ok, for me all i would do/Add would be a by pass switch, and I would look at changing the relays for solid state. the last comment however is spendy and purely based on the fact i have had 3 relays pack in over the last month!! Nothing important running on them but I am starting to dislike contact relays .
As for the logic I assume you can adjust the 20 min thing in your loop? Or is that on the thermostat?
Depending how cold it was I would want to control that part of the loop if needed, but I am in Scotland and you are there so I doubt conditions are the same.
So yeah thumbs up from me it looks like it should do the job, and seeing as you building the pic circuit there is nothing stopping you tweaking the code if you find you need to.

 

[nsaspook]

I think it looks ok, for me all i would do/Add would be a by pass switch, and I would look at changing the relays for solid state. the last comment however is spendy and purely based on the fact i have had 3 relays pack in over the last month!! Nothing important running on them but I am starting to dislike contact relays .

I've had lots of problem with cheap relays but for a critical control circuit I still tend to use them. I really like the Magnecraft types like this for when a manual override (on the relay) for circuit power is needed if the controller is dead.
https://www.mouser.com/ds/2/357/850-0210-204252.pdf