Heating Issues

Mr_Pom

Hi, I believe it's a common issue but when I select hot water only my heating also comes on. I've done a bit of investigating and notice that the mid-position valve, Seimens DVA3, is mega hot, nearly too hot to touch. Also as soon as hot water is selected on, the actuator goes to the 'manual' mode and the lever is free to move and ineffective. Syncronous motor change, actuator box change or something more sinister. Thanks in advance.

Alex1983

Does the heating work if you select central heating only? If it does then its probably not the motor or head. It’s likely to be dirt on the valve seating allowing water to pass to the heating when you select hot water only.

Le_Kirk

I have had this happen twice. first time it was a bit of dirt as per post #2 and the second time it was a failed component in the head - the plastic pillar that holds the spring (for spring return) had snapped and was not allowing the motor to move the valve. Temporarily fixed by using a screw to replace the plastic pillar until I could buy a replacement head. I cleared the dirt by constantly working the valve with the manual lever until it cleared.

Alex1983

Le_Kirk in work we use plastic nuts and bolts when the clips snap and leave it as a permanent repair, saves you replacing the actuator if you ever get it again.

Le_Kirk

Thanks for that ^^^^ but it wasn't the clip it was the plastic pillar. I note that on the replacement head, the design had been changed for a metal pillar!!