La Marzocco Linea Classic Pump Runs with Hot Water

#1: Post by **amateurdad** » November 16th, 2021, 11:38 am

Hi all,

Recently refurbished a Linea Classic 2grp and on testing the hot water tap, the pump runs constantly when it's dispensing.

The main PCB is new, as is the hot water switch and touchpads.

Anyone come across this before?

Cheers

#2: Post by **Brew who** » December 3rd, 2021, 2:13 am

Probably one of the jumpers on the board- compare the jumper positions between the new board and any other linea boards you may have.

or it's a software programmable setting but I could tell you how

#3: Post by **Giampiero** » December 3rd, 2021, 4:27 am

Probably a sort of mixing hot/cold water function is enabled?

#4: Post by **jpboyt** » December 5th, 2021, 9:24 pm

Compare P2, P3, and P4 jumpers. Jumper on adds pump to operation. P4 is normally on as it is pump and fill. P3 and P4 depend on whether or not you want pump with water. Which relay is activated depends on whether you connect the 6 wire hot water switch to touch pad 1 or 2. Third relay on newer board replaces triac used on older boards. Triacs tend to fail conductive which is why I suspect that switched to a relay.
jpboyt