Continously running pump

Edward67 · May 4, 2023

Friend asked me to wire in a hive on a conventional 1 zone heating system. So I fitted it tested the HIVE and all was working.
I then said to him after about 20 minutes your pump is still running even though water and heat were turned off.
Response it's always been like it. So me been fussy reinstalled his old stat and programmer and yes pump continuously runs.
The 3 port valve had moved over to the water side as expected when nothing is calling but it just seems wrong to me.
Pump is at least 10 years old and the 3 port is approximately 10 years old.
Any help guidance appreciated.
Thx.

Edward67 · May 4, 2023

Sorry boiler is a potterton prima B

Mike Johnson · May 4, 2023

Sounds to me like the three port valve is wired up incorrectly and demands the pump to be on when no demand for heating, check the CH junction box is wired up to the correct Y plan.

Edward67 · May 4, 2023

I agree somethings not right but surely it can't have been like this for years?

Edward67 · May 4, 2023

Edward67 said:
I agree somethings not right but surely it can't have been like this for years?

This is a picture of the untouched y plan. From the bottom 1,2,3,4 were too the stat so I removed these and linked 1 and 4 together. I know it's hard from Pic but I imagine you experienced engineers will probably see any issue straight away.
This is how it's been for at least a decade