Diverter valve hot on a switched off system

[mswift]

I have not used my CH system (neither CH or DHW) for a while now. The system is switched off at the Honeywell programmer. Have noticed that the Honeywell mid-position diverter is hot to the touch. The pipes entering/leaving the diverter are cold. Please can you help because I'm a little worried about a fire risk. Thanks.

 

[newbie1]

best to get it replaced as both ch and dhw are off valve should be doing nothing if boiler isnt firing

 

[wildcard]

If the boilers not firing which it obviously is not as you say the pipes are cold around the valve,then the valve body is seized.Short answer needs replacing.

 

[Plumbstar Tom]

sounds like a motor fault to me so as above get it replaced

 

[doitmyself]

The system is switched off at the Honeywell programmer. Have noticed that the Honeywell mid-position diverter is hot to the touch.

Presumably you have just set the programmer to CH OFF and HW OFF. The problem with this is that, if the Valve was in the CH only position when you turned the programmer OFF, there will still be current through the motor from the HW OFF terminal, holding it in the CH only position.

What you need to do is turn the power to the programmer off, which will reset the valve to the default HW only position. You can turn the power back on if you want to. Alternatively set the HW thermostat to Min and turn the programmer to HW ON, this also resets the valve.