3 way valve replaced and not working

[Sime]

the old 3 way valve honeywell unit replaced after a power cut central heating works no hot water so I replaced it and now still no hot water and the unit is warm too touch like the old one i replaced any ideas wondering about changing the programmer which is Towerchron 2000 help needed thanks

 

[charliejamesuk]

Sure the manual arm is not stuck? Had this with one recently.

 

[doitmyself]

It will be either the cylinder thermostat or the programmer

Central heating only lights the boiler via the orange wire from the valve.
HW only or HW & CH lights the boiler via the cylinder stat, which is powered from HW On terminal of the timer.


If you have a multimeter:

Check for 240V at the programmer HW ON terminal, with HW ON continuously.
NO 240v = faulty programmer

If OK, check 240V at the common terminal of the cylinder stat
NO 240 V = faulty wire from programmer to cyl stat

If OK, turn cyl stat to Max and check for 240V on terminal 1 of cylc stat
NO 240v = faulty cyl stat.

If OK, check for 240V on terminal with valve orange wire connected.
NO 240V = faulty wire to cyl stat.

The boiler should still light if the lever is locked in the MAN position.

Motorized valves do get warm to the touch - it does not mean it is faulty. So you may have changed it unnecessarily.

 

[dontknowitall]

Take note dkia!!!